# Provider Driver Development Guide

This document is intended as a guide for developers creating provider drivers for the Octavia API. This guide is intended to be an up to date version of the provider driver specification previously approved.

## How Provider Drivers Integrate

Available drivers will be enabled by entries in the Octavia configuration file. Drivers will be loaded via stevedore and Octavia will communicate with drivers through a standard class interface defined below. Most driver functions will be asynchronous to Octavia, and Octavia will provide a library of functions that give drivers a way to update status and statistics. Functions that are synchronous are noted below.

Octavia API functions not listed here will continue to be handled by the Octavia API and will not call into the driver. Examples would be show, list, and quota requests.

In addition, drivers may provide a provider agent that the Octavia driver-agent will launch at start up. This is a long-running process that is intended to support the provider driver.

### Driver Entry Points

Provider drivers will be loaded via stevedore. Drivers will have an entry point defined in their setup tools configuration using the Octavia driver namespace “octavia.api.drivers”. This entry point name will be used to enable the driver in the Octavia configuration file and as the “provider” parameter users specify when creating a load balancer. An example for the octavia reference driver would be:

    amphora = octavia.api.drivers.amphora_driver.driver:AmphoraProviderDriver

In addition, provider drivers may provide a provider agent also defined by a setup tools entry point. The provider agent namespace is “octavia.driver_agent.provider_agents”. This will be called once, at Octavia driver-agent start up, to launch a long-running process. Provider agents must be enabled in the Octavia configuration file. An example provider agent entry point would be:

    amphora_agent = octavia.api.drivers.amphora_driver.agent:AmphoraProviderAgent

## Stable Provider Driver Interface

Provider drivers should only access the following Octavia APIs. All other Octavia APIs are not considered stable or safe for provider driver use and may change at any time.

- octavia_lib.api.drivers.data_models
- octavia_lib.api.drivers.driver_lib
- octavia_lib.api.drivers.exceptions
- octavia_lib.api.drivers.provider_base
- octavia_lib.common.constants

## Octavia Provider Driver API

Provider drivers will be expected to support the full interface described by the Octavia API, currently v2.0. If a driver does not implement an API function, drivers should fail a request by raising a `NotImplementedError` exception. If a driver implements a function but does not support a particular option passed in by the caller, the driver should raise an `UnsupportedOptionError`.

It is recommended that drivers use the jsonschema package or voluptuous to validate the request against the current driver capabilities.

See the Exception Model below for more details.

Note

Driver developers should refer to the official Octavia API reference document for details of the fields and expected outcome of these calls.

### Load balancer

#### Create

Creates a load balancer.

Octavia will pass in the load balancer object with all requested settings.

The load balancer will be in the `PENDING_CREATE` provisioning_status and `OFFLINE` operating_status when it is passed to the driver. The driver will be responsible for updating the provisioning status of the load balancer to either `ACTIVE` if successfully created, or `ERROR` if not created.

The Octavia API will accept and do basic API validation of the create request from the user. The load balancer python object representing the request body will be passed to the driver create method as it was received and validated with the following exceptions:

1. The provider will be removed as this is used for driver selection.
2. The flavor will be expanded from the provided ID to be the full dictionary representing the flavor metadata.

Load balancer object

As of the writing of this specification the create load balancer object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
description | string | A human-readable description for the resource.
flavor | dict | The flavor keys and values.
availability_zone | dict | The availability zone keys and values.
listeners | list | A list of Listener objects.
loadbalancer_id | string | ID of load balancer to create.
name | string | Human-readable name of the resource.
pools | list | A list of Pool object.
project_id | string | ID of the project owning this resource.
vip_address | string | The IP address of the Virtual IP (VIP).
vip_network_id | string | The ID of the network for the VIP.
vip_port_id | string | The ID of the VIP port.
vip_qos_policy_id | string | The ID of the qos policy for the VIP.
vip_subnet_id | string | The ID of the subnet for the VIP.

The driver is expected to validate that the driver supports the request and raise an exception if the request cannot be accepted.

VIP port creation

Some provider drivers will want to create the Neutron port for the VIP, and others will want Octavia to create the port instead. In order to support both use cases, the create_vip_port() method will ask provider drivers to create a VIP port. If the driver expects Octavia to create the port, the driver will raise a NotImplementedError exception. Octavia will call this function before calling loadbalancer_create() in order to determine if it should create the VIP port. Octavia will call create_vip_port() with a loadbalancer ID and a partially defined VIP dictionary. Provider drivers that support port creation will create the port and return a fully populated VIP dictionary.

VIP dictionary

Name | Type | Description
--- | --- | ---
project_id | string | ID of the project owning this resource.
vip_address | string | The IP address of the Virtual IP (VIP).
vip_network_id | string | The ID of the network for the VIP.
vip_port_id | string | The ID of the VIP port.
vip_qos_policy_id | string | The ID of the qos policy for the VIP.
vip_subnet_id | string | The ID of the subnet for the VIP.

Creating a Fully Populated Load Balancer

If the “listener” option is specified, the provider driver will iterate through the list and create all of the child objects in addition to creating the load balancer instance.

#### Delete

Removes an existing load balancer.

Octavia will pass in the load balancer object and cascade boolean as parameters.

The load balancer will be in the `PENDING_DELETE` provisioning_status when it is passed to the driver. The driver will notify Octavia that the delete was successful by setting the provisioning_status to `DELETED`. If the delete failed, the driver will update the provisioning_status to `ERROR`.

The API includes an option for cascade delete. When cascade is set to True, the provider driver will delete all child objects of the load balancer.

#### Failover

Performs a failover of a load balancer.

Octavia will pass in the load balancer ID as a parameter.

The load balancer will be in the `PENDING_UPDATE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the load balancer to either `ACTIVE` if successfully failed over, or `ERROR` if not failed over.

Failover can mean different things in the context of a provider driver. For example, the Octavia driver replaces the current amphora(s) with another amphora. For another provider driver, failover may mean failing over from an active system to a standby system.

#### Update

Modifies an existing load balancer using the values supplied in the load balancer object.

Octavia will pass in the original load balancer object which is the baseline for the update, and a load balancer object with the fields to be updated. Fields not updated by the user will contain “Unset” as defined in the data model.

As of the writing of this specification the update load balancer object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
description | string | A human-readable description for the resource.
loadbalancer_id | string | ID of load balancer to update.
name | string | Human-readable name of the resource.
vip_qos_policy_id | string | The ID of the qos policy for the VIP.

The load balancer will be in the `PENDING_UPDATE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the load balancer to either `ACTIVE` if successfully updated, or `ERROR` if the update was not successful.

The driver is expected to validate that the driver supports the request. The method will then return or raise an exception if the request cannot be accepted.

Abstract class definition

    class Driver(object):

      def create_vip_port(self, loadbalancer_id, vip_dictionary):
          """Creates a port for a load balancer VIP.

          If the driver supports creating VIP ports, the driver will create a
          VIP port and return the vip_dictionary populated with the vip_port_id.
          If the driver does not support port creation, the driver will raise
          a NotImplementedError.

          :param: loadbalancer_id (string): ID of loadbalancer.
          :param: vip_dictionary (dict): The VIP dictionary.
          :returns: VIP dictionary with vip_port_id.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: The driver does not support creating
            VIP ports.
          """
          raise NotImplementedError()

      def loadbalancer_create(self, loadbalancer):
          """Creates a new load balancer.

          :param loadbalancer (object): The load balancer object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: The driver does not support create.
          :raises UnsupportedOptionError: The driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

      def loadbalancer_delete(self, loadbalancer, cascade=False):
          """Deletes a load balancer.

          :param loadbalancer (object): The load balancer object.
          :param cascade (bool): If True, deletes all child objects (listeners,
            pools, etc.) in addition to the load balancer.
          :return: Nothing if the delete request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          """
          raise NotImplementedError()

      def loadbalancer_failover(self, loadbalancer_id):
          """Performs a fail over of a load balancer.

          :param loadbalancer_id (string): ID of the load balancer to failover.
          :return: Nothing if the failover request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises: NotImplementedError if driver does not support request.
          """
          raise NotImplementedError()

      def loadbalancer_update(self, old_loadbalancer, new_loadbalancer):
          """Updates a load balancer.

          :param old_loadbalancer (object): The baseline load balancer object.
          :param new_loadbalancer (object): The updated load balancer object.
          :return: Nothing if the update request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: The driver does not support request.
          :raises UnsupportedOptionError: The driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

### Listener

#### Create

Creates a listener for a load balancer.

Octavia will pass in the listener object with all requested settings.

The listener will be in the `PENDING_CREATE` provisioning_status and `OFFLINE` operating_status when it is passed to the driver. The driver will be responsible for updating the provisioning status of the listener to either `ACTIVE` if successfully created, or `ERROR` if not created.

The Octavia API will accept and do basic API validation of the create request from the user. The listener python object representing the request body will be passed to the driver create method as it was received and validated with the following exceptions:

1. The project_id will be removed, if present, as this field is now deprecated. The listener will inherit the project_id from the parent load balancer. 2. The default_tls_container_ref will be expanded and provided to the driver in PEM format. 3. The sni_container_refs will be expanded and provided to the driver in PEM format.

Listener object

As of the writing of this specification the create listener object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
client_authentication | string | The TLS client authentication mode. One of the options `NONE`, `OPTIONAL` or `MANDATORY`.
client_ca_tls_container_data | string | A PEM encoded certificate.
client_ca_tls_container_ref | string | The reference to the secrets container.
client_crl_container_data | string | A PEM encoded CRL file.
client_crl_container_ref | string | The reference to the secrets container.
connection_limit | int | The max number of connections permitted for this listener. Default is -1, which is infinite connections.
default_pool | object | A Pool object.
default_pool_id | string | The ID of the pool used by the listener if no L7 policies match.
default_tls_container_data | dict | A TLS container dict.
default_tls_container_refs | string | The reference to the secrets container.
description | string | A human-readable description for the listener.
insert_headers | dict | A dictionary of optional headers to insert into the request before it is sent to the backend member. See Supported HTTP Header Insertions. Keys and values are specified as strings.
l7policies | list | A list of L7policy objects.
listener_id | string | ID of listener to create.
loadbalancer_id | string | ID of load balancer.
name | string | Human-readable name of the listener.
project_id | string | ID of the project owning this resource.
protocol | string | Protocol type: One of HTTP, HTTPS, TCP, or TERMINATED_HTTPS.
protocol_port | int | Protocol port number.
sni_container_data | list | A list of TLS container dict.
sni_container_refs | list | A list of references to the SNI secrets containers.
timeout_client_data | int | Frontend client inactivity timeout in milliseconds.
timeout_member_connect | int | Backend member connection timeout in milliseconds.
timeout_member_data | int | Backend member inactivity timeout in milliseconds.
timeout_tcp_inspect | int | Time, in milliseconds, to wait for additional TCP packets for content inspection.
allowed_cidrs | list | List of IPv4 or IPv6 CIDRs.

As of the writing of this specification the TLS container dictionary contains the following:

Key | Type | Description
--- | --- | ---
certificate | string | The PEM encoded certificate.
intermediates | List | A list of intermediate PEM certificates.
passphrase | string | The private_key passphrase.
primary_cn | string | The primary common name of the certificate.
private_key | string | The PEM encoded private key.

As of the writing of this specification the Supported HTTP Header Insertions are:

Key | Type | Description
--- | --- | ---
X-Forwarded-For | bool | When True a X-Forwarded-For header is inserted into the request to the backend member that specifies the client IP address.
X-Forwarded-Port | int | A X-Forwarded-Port header is inserted into the request to the backend member that specifies the integer provided. Typically this is used to indicate the port the client connected to on the load balancer.
X-Forwarded-Proto | bool | A X-Forwarded-Proto header is inserted into the end of request to the backend member. HTTP for the HTTP listener protocol type, HTTPS for the TERMINATED_HTTPS listener protocol type.
X-SSL-Client-Verify | string | When “`true`” a `X-SSL-Client-Verify` header is inserted into the request to the backend `member` that contains 0 if the client authentication was successful, or an result error number greater than 0 that align to the openssl veryify error codes.
X-SSL-Client-Has-Cert | string | When “`true`” a `X-SSL-Client-Has-Cert` header is inserted into the request to the backend `member` that is ‘’true’’ if a client authentication certificate was presented, and ‘’false’’ if not. Does not indicate validity.
X-SSL-Client-DN | string | When “`true`” a `X-SSL-Client-DN` header is inserted into the request to the backend `member` that contains the full Distinguished Name of the certificate presented by the client.
X-SSL-Client-CN | string | When “`true`” a `X-SSL-Client-CN` header is inserted into the request to the backend `member` that contains the Common Name from the full Distinguished Name of the certificate presented by the client.
X-SSL-Issuer | string | When “`true`” a `X-SSL-Issuer` header is inserted into the request to the backend `member` that contains the full Distinguished Name of the client certificate issuer.
X-SSL-Client-SHA1 | string | When “`true`” a `X-SSL-Client-SHA1` header is inserted into the request to the backend `member` that contains the SHA-1 fingerprint of the certificate presented by the client in hex string format.
X-SSL-Client-Not-Before | string | When “`true`” a `X-SSL-Client-Not-Before` header is inserted into the request to the backend `member` that contains the start date presented by the client as a formatted string YYMMDDhhmmss[Z].
X-SSL-Client-Not-After | string | When “`true`” a `X-SSL-Client-Not-After` header is inserted into the request to the backend `member` that contains the end date presented by the client as a formatted string YYMMDDhhmmss[Z].

Creating a Fully Populated Listener

If the “default_pool” or “l7policies” option is specified, the provider driver will create all of the child objects in addition to creating the listener instance.

#### Delete

Deletes an existing listener.

Octavia will pass the listener object as a parameter.

The listener will be in the `PENDING_DELETE` provisioning_status when it is passed to the driver. The driver will notify Octavia that the delete was successful by setting the provisioning_status to `DELETED`. If the delete failed, the driver will update the provisioning_status to `ERROR`.

#### Update

Modifies an existing listener using the values supplied in the listener object.

Octavia will pass in the original listener object which is the baseline for the update, and a listener object with the fields to be updated. Fields not updated by the user will contain “Unset” as defined in the data model.

As of the writing of this specification the update listener object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
client_authentication | string | The TLS client authentication mode. One of the options `NONE`, `OPTIONAL` or `MANDATORY`.
client_ca_tls_container_data | string | A PEM encoded certificate.
client_ca_tls_container_ref | string | The reference to the secrets container.
client_crl_container_data | string | A PEM encoded CRL file.
client_crl_container_ref | string | The reference to the secrets container.
connection_limit | int | The max number of connections permitted for this listener. Default is -1, which is infinite connections.
default_pool_id | string | The ID of the pool used by the listener if no L7 policies match.
default_tls_container_data | dict | A TLS container dict.
default_tls_container_refs | string | The reference to the secrets container.
description | string | A human-readable description for the listener.
insert_headers | dict | A dictionary of optional headers to insert into the request before it is sent to the backend member. See Supported HTTP Header Insertions. Keys and values are specified as strings.
listener_id | string | ID of listener to update.
name | string | Human-readable name of the listener.
sni_container_data | list | A list of TLS container dict.
sni_container_refs | list | A list of references to the SNI secrets containers.
timeout_client_data | int | Frontend client inactivity timeout in milliseconds.
timeout_member_connect | int | Backend member connection timeout in milliseconds.
timeout_member_data | int | Backend member inactivity timeout in milliseconds.
timeout_tcp_inspect | int | Time, in milliseconds, to wait for additional TCP packets for content inspection.
allowed_cidrs | list | List of IPv4 or IPv6 CIDRs.

The listener will be in the `PENDING_UPDATE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the listener to either `ACTIVE` if successfully updated, or `ERROR` if the update was not successful.

The driver is expected to validate that the driver supports the request. The method will then return or raise an exception if the request cannot be accepted.

Abstract class definition

    class Driver(object):
      def listener_create(self, listener):
          """Creates a new listener.

          :param listener (object): The listener object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
        raise NotImplementedError()

      def listener_delete(self, listener):
          """Deletes a listener.

          :param listener (object): The listener object.
          :return: Nothing if the delete request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          """
          raise NotImplementedError()

      def listener_update(self, old_listener, new_listener):
          """Updates a listener.

          :param old_listener (object): The baseline listener object.
          :param new_listener (object): The updated listener object.
          :return: Nothing if the update request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

### Pool

#### Create

Creates a pool for a load balancer.

Octavia will pass in the pool object with all requested settings.

The pool will be in the `PENDING_CREATE` provisioning_status and `OFFLINE` operating_status when it is passed to the driver. The driver will be responsible for updating the provisioning status of the pool to either `ACTIVE` if successfully created, or `ERROR` if not created.

The Octavia API will accept and do basic API validation of the create request from the user. The pool python object representing the request body will be passed to the driver create method as it was received and validated with the following exceptions:

1. The project_id will be removed, if present, as this field is now deprecated. The listener will inherit the project_id from the parent load balancer.

Pool object

As of the writing of this specification the create pool object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
ca_tls_container_data | string | A PEM encoded certificate.
ca_tls_container_ref | string | The reference to the secrets container.
crl_container_data | string | A PEM encoded CRL file.
crl_container_ref | string | The reference to the secrets container.
description | string | A human-readable description for the pool.
healthmonitor | object | A Healthmonitor object.
lb_algorithm | string | Load balancing algorithm: One of ROUND_ROBIN, LEAST_CONNECTIONS, SOURCE_IP or SOURCE_IP_PORT.
loadbalancer_id | string | ID of load balancer.
listener_id | string | ID of listener.
members | list | A list of Member objects.
name | string | Human-readable name of the pool.
pool_id | string | ID of pool to create.
project_id | string | ID of the project owning this resource.
protocol | string | Protocol type: One of HTTP, HTTPS, PROXY, or TCP.
session_persistence | dict | Defines session persistence as one of {‘type’: <’HTTP_COOKIE’ | ‘SOURCE_IP’>} OR {‘type’: ‘APP_COOKIE’, ‘cookie_name’: <cookie_name>}
tls_container_data | dict | A TLS container dict.
tls_container_ref | string | The reference to the secrets container.
tls_enabled | bool | True when backend re-encryption is enabled.

#### Delete

Removes an existing pool and all of its members.

Octavia will pass the pool object as a parameter.

The pool will be in the `PENDING_DELETE` provisioning_status when it is passed to the driver. The driver will notify Octavia that the delete was successful by setting the provisioning_status to `DELETED`. If the delete failed, the driver will update the provisioning_status to `ERROR`.

#### Update

Modifies an existing pool using the values supplied in the pool object.

Octavia will pass in the original pool object which is the baseline for the update, and a pool object with the fields to be updated. Fields not updated by the user will contain “Unset” as defined in the data model.

As of the writing of this specification the update pool object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
ca_tls_container_data | string | A PEM encoded certificate.
ca_tls_container_ref | string | The reference to the secrets container.
crl_container_data | string | A PEM encoded CRL file.
crl_container_ref | string | The reference to the secrets container.
description | string | A human-readable description for the pool.
lb_algorithm | string | Load balancing algorithm: One of ROUND_ROBIN, LEAST_CONNECTIONS, or SOURCE_IP.
name | string | Human-readable name of the pool.
pool_id | string | ID of pool to update.
session_persistence | dict | Defines session persistence as one of {‘type’: <’HTTP_COOKIE’ | ‘SOURCE_IP’>} OR {‘type’: ‘APP_COOKIE’, ‘cookie_name’: <cookie_name>}
tls_container_data | dict | A TLS container dict.
tls_container_ref | string | The reference to the secrets container.
tls_enabled | bool | True when backend re-encryption is enabled.

The pool will be in the `PENDING_UPDATE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the pool to either `ACTIVE` if successfully updated, or `ERROR` if the update was not successful.

The driver is expected to validate that the driver supports the request. The method will then return or raise an exception if the request cannot be accepted.

Abstract class definition

    class Driver(object):
      def pool_create(self, pool):
          """Creates a new pool.

          :param pool (object): The pool object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

      def pool_delete(self, pool):
          """Deletes a pool and its members.

          :param pool (object): The pool object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          """
          raise NotImplementedError()

      def pool_update(self, old_pool, new_pool):
          """Updates a pool.

          :param old_pool (object): The baseline pool object.
          :param new_pool (object): The updated pool object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

### Member

#### Create

Creates a member for a pool.

Octavia will pass in the member object with all requested settings.

The member will be in the `PENDING_CREATE` provisioning_status and `OFFLINE` operating_status when it is passed to the driver. The driver will be responsible for updating the provisioning status of the member to either `ACTIVE` if successfully created, or `ERROR` if not created.

The Octavia API will accept and do basic API validation of the create request from the user. The member python object representing the request body will be passed to the driver create method as it was received and validated with the following exceptions:

1. The project_id will be removed, if present, as this field is now deprecated. The member will inherit the project_id from the parent load balancer.

Member object

As of the writing of this specification the create member object may contain the following:

Name | Type | Description
--- | --- | ---
address | string | The IP address of the backend member to receive traffic from the load balancer.
admin_state_up | bool | Admin state: True if up, False if down.
backup | bool | Is the member a backup? Backup members only receive traffic when all non-backup members are down.
member_id | string | ID of member to create.
monitor_address | string | An alternate IP address used for health monitoring a backend member.
monitor_port | int | An alternate protocol port used for health monitoring a backend member.
name | string | Human-readable name of the member.
pool_id | string | ID of pool.
project_id | string | ID of the project owning this resource.
protocol_port | int | The port on which the backend member listens for traffic.
subnet_id | string | Subnet ID.

weight

int

The weight of a member determines the portion of requests or connections it services compared to the other members of the pool. For example, a member with a weight of 10 receives five times as many requests as a member with a weight of 2. A value of 0 means the member does not receive new connections but continues to service existing connections. A valid value is from 0 to 256. Default is 1.

#### Delete

Removes a pool member.

Octavia will pass the member object as a parameter.

The member will be in the `PENDING_DELETE` provisioning_status when it is passed to the driver. The driver will notify Octavia that the delete was successful by setting the provisioning_status to `DELETED`. If the delete failed, the driver will update the provisioning_status to `ERROR`.

#### Update

Modifies an existing member using the values supplied in the listener object.

Octavia will pass in the original member object which is the baseline for the update, and a member object with the fields to be updated. Fields not updated by the user will contain “Unset” as defined in the data model.

As of the writing of this specification the update member object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
backup | bool | Is the member a backup? Backup members only receive traffic when all non-backup members are down.
member_id | string | ID of member to update.
monitor_address | string | An alternate IP address used for health monitoring a backend member.
monitor_port | int | An alternate protocol port used for health monitoring a backend member.
name | string | Human-readable name of the member.

weight

int

The weight of a member determines the portion of requests or connections it services compared to the other members of the pool. For example, a member with a weight of 10 receives five times as many requests as a member with a weight of 2. A value of 0 means the member does not receive new connections but continues to service existing connections. A valid value is from 0 to 256. Default is 1.

The member will be in the `PENDING_UPDATE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the member to either `ACTIVE` if successfully updated, or `ERROR` if the update was not successful.

The driver is expected to validate that the driver supports the request. The method will then return or raise an exception if the request cannot be accepted.

#### Batch Update

Set the state of members for a pool in one API call. This may include creating new members, deleting old members, and updating existing members. Existing members are matched based on address/port combination.

For example, assume a pool currently has two members. These members have the following address/port combinations: ‘192.0.2.15:80’ and ‘192.0.2.16:80’. Now assume a PUT request is made that includes members with address/port combinations: ‘192.0.2.16:80’ and ‘192.0.2.17:80’. The member ‘192.0.2.15:80’ will be deleted because it was not in the request. The member ‘192.0.2.16:80’ will be updated to match the request data for that member, because it was matched. The member ‘192.0.2.17:80’ will be created, because no such member existed.

The members will be in the `PENDING_CREATE`, `PENDING_UPDATE`, or `PENDING_DELETE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the members to either `ACTIVE` or `DELETED` if successfully updated, or `ERROR` if the update was not successful.

The batch update method will supply a list of Member objects. Existing members not in this list should be deleted, existing members in the list should be updated, and members in the list that do not already exist should be created.

Abstract class definition

    class Driver(object):
      def member_create(self, member):
          """Creates a new member for a pool.

          :param member (object): The member object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
      raise NotImplementedError()

      def member_delete(self, member):

          """Deletes a pool member.

          :param member (object): The member object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          """
          raise NotImplementedError()

      def member_update(self, old_member, new_member):

          """Updates a pool member.

          :param old_member (object): The baseline member object.
          :param new_member (object): The updated member object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

      def member_batch_update(self, pool_id, members):
          """Creates, updates, or deletes a set of pool members.

          :param pool_id (string): The id of the pool to update.
          :param members (list): List of member objects.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

### Health Monitor

#### Create

Creates a health monitor on a pool.

Octavia will pass in the health monitor object with all requested settings.

The health monitor will be in the `PENDING_CREATE` provisioning_status and `OFFLINE` operating_status when it is passed to the driver. The driver will be responsible for updating the provisioning status of the health monitor to either `ACTIVE` if successfully created, or `ERROR` if not created.

The Octavia API will accept and do basic API validation of the create request from the user. The healthmonitor python object representing the request body will be passed to the driver create method as it was received and validated with the following exceptions:

1. The project_id will be removed, if present, as this field is now deprecated. The listener will inherit the project_id from the parent load balancer.

Healthmonitor object

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
delay | int | The interval, in seconds, between health checks.
domain_name | string | The domain name to be passed in the host header for health monitor checks.
expected_codes | string | The expected HTTP status codes to get from a successful health check. This may be a single value, a list, or a range.
healthmonitor_id | string | ID of health monitor to create.
http_method | string | The HTTP method that the health monitor uses for requests. One of CONNECT, DELETE, GET, HEAD, OPTIONS, PATCH, POST, PUT, or TRACE.
http_version | float | The HTTP version to use for health monitor connections. One of ‘1.0’ or ‘1.1’. Defaults to ‘1.0’.
max_retries | int | The number of successful checks before changing the operating status of the member to ONLINE.
max_retries_down | int | The number of allowed check failures before changing the operating status of the member to ERROR. A valid value is from 1 to 10.
name | string | Human-readable name of the monitor.
pool_id | string | The pool to monitor.
project_id | string | ID of the project owning this resource.
timeout | int | The time, in seconds, after which a health check times out. This value must be less than the delay value.
type | string | The type of health monitor. One of HTTP, HTTPS, PING, TCP, TLS-HELLO or UDP-CONNECT.
url_path | string | The HTTP URL path of the request sent by the monitor to test the health of a backend member. Must be a string that begins with a forward slash (/).

#### Delete

Deletes an existing health monitor.

Octavia will pass in the health monitor object as a parameter.

The health monitor will be in the `PENDING_DELETE` provisioning_status when it is passed to the driver. The driver will notify Octavia that the delete was successful by setting the provisioning_status to `DELETED`. If the delete failed, the driver will update the provisioning_status to `ERROR`.

#### Update

Modifies an existing health monitor using the values supplied in the health monitor object.

Octavia will pass in the original health monitor object which is the baseline for the update, and a health monitor object with the fields to be updated. Fields not updated by the user will contain “Unset” as defined in the data model.

As of the writing of this specification the update health monitor object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
delay | int | The interval, in seconds, between health checks.
domain_name | string | The domain name to be passed in the host header for health monitor checks.
expected_codes | string | The expected HTTP status codes to get from a successful health check. This may be a single value, a list, or a range.
healthmonitor_id | string | ID of health monitor to create.
http_method | string | The HTTP method that the health monitor uses for requests. One of CONNECT, DELETE, GET, HEAD, OPTIONS, PATCH, POST, PUT, or TRACE.
http_version | float | The HTTP version to use for health monitor connections. One of ‘1.0’ or ‘1.1’. Defaults to ‘1.0’.
max_retries | int | The number of successful checks before changing the operating status of the member to ONLINE.
max_retries_down | int | The number of allowed check failures before changing the operating status of the member to ERROR. A valid value is from 1 to 10.
name | string | Human-readable name of the monitor.
timeout | int | The time, in seconds, after which a health check times out. This value must be less than the delay value.
url_path | string | The HTTP URL path of the request sent by the monitor to test the health of a backend member. Must be a string that begins with a forward slash (/).

The health monitor will be in the `PENDING_UPDATE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the health monitor to either `ACTIVE` if successfully updated, or `ERROR` if the update was not successful.

The driver is expected to validate that the driver supports the request. The method will then return or raise an exception if the request cannot be accepted.

Abstract class definition

    class Driver(object):
      def health_monitor_create(self, healthmonitor):
          """Creates a new health monitor.

          :param healthmonitor (object): The health monitor object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

      def health_monitor_delete(self, healthmonitor):
          """Deletes a healthmonitor_id.

          :param healthmonitor (object): The health monitor object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          """
          raise NotImplementedError()

      def health_monitor_update(self, old_healthmonitor, new_healthmonitor):
          """Updates a health monitor.

          :param old_healthmonitor (object): The baseline health monitor
            object.
          :param new_healthmonitor (object): The updated health monitor object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

### L7 Policy

#### Create

Creates an L7 policy.

Octavia will pass in the L7 policy object with all requested settings.

The L7 policy will be in the `PENDING_CREATE` provisioning_status and `OFFLINE` operating_status when it is passed to the driver. The driver will be responsible for updating the provisioning status of the L7 policy to either `ACTIVE` if successfully created, or `ERROR` if not created.

The Octavia API will accept and do basic API validation of the create request from the user. The l7policy python object representing the request body will be passed to the driver create method as it was received and validated with the following exceptions:

1. The project_id will be removed, if present, as this field is now deprecated. The l7policy will inherit the project_id from the parent load balancer.

L7policy object

As of the writing of this specification the create l7policy object may contain the following:

Name | Type | Description
--- | --- | ---
action | string | The L7 policy action. One of REDIRECT_TO_POOL, REDIRECT_TO_URL, or REJECT.
admin_state_up | bool | Admin state: True if up, False if down.
description | string | A human-readable description for the L7 policy.
l7policy_id | string | The ID of the L7 policy.
listener_id | string | The ID of the listener.
name | string | Human-readable name of the L7 policy.
position | int | The position of this policy on the listener. Positions start at 1.
project_id | string | ID of the project owning this resource.
redirect_http_code | int | The HTTP status code to be returned on a redirect policy.
redirect_pool_id | string | Requests matching this policy will be redirected to the pool with this ID. Only valid if action is REDIRECT_TO_POOL.
redirect_prefix | string | Requests matching this policy will be redirected to this Prefix URL. Only valid if `action` is `REDIRECT_PREFIX`.
redirect_url | string | Requests matching this policy will be redirected to this URL. Only valid if action is REDIRECT_TO_URL.
rules | list | A list of l7rule objects.

Creating a Fully Populated L7 policy

If the “rules” option is specified, the provider driver will create all of the child objects in addition to creating the L7 policy instance.

#### Delete

Deletes an existing L7 policy.

Octavia will pass in the L7 policy object as a parameter.

The l7policy will be in the `PENDING_DELETE` provisioning_status when it is passed to the driver. The driver will notify Octavia that the delete was successful by setting the provisioning_status to `DELETED`. If the delete failed, the driver will update the provisioning_status to `ERROR`.

#### Update

Modifies an existing L7 policy using the values supplied in the l7policy object.

Octavia will pass in the original L7 policy object which is the baseline for the update, and an L7 policy object with the fields to be updated. Fields not updated by the user will contain “Unset” as defined in the data model.

As of the writing of this specification the update L7 policy object may contain the following:

Name | Type | Description
--- | --- | ---
action | string | The L7 policy action. One of REDIRECT_TO_POOL, REDIRECT_TO_URL, or REJECT.
admin_state_up | bool | Admin state: True if up, False if down.
description | string | A human-readable description for the L7 policy.
l7policy_id | string | The ID of the L7 policy.
name | string | Human-readable name of the L7 policy.
position | int | The position of this policy on the listener. Positions start at 1.
redirect_http_code | int | The HTTP status code to be returned on a redirect policy.
redirect_pool_id | string | Requests matching this policy will be redirected to the pool with this ID. Only valid if action is REDIRECT_TO_POOL.
redirect_prefix | string | Requests matching this policy will be redirected to this Prefix URL. Only valid if `action` is `REDIRECT_PREFIX`.
redirect_url | string | Requests matching this policy will be redirected to this URL. Only valid if action is REDIRECT_TO_URL.

The L7 policy will be in the `PENDING_UPDATE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the L7 policy to either `ACTIVE` if successfully updated, or `ERROR` if the update was not successful.

The driver is expected to validate that the driver supports the request. The method will then return or raise an exception if the request cannot be accepted.

Abstract class definition

    class Driver(object):
      def l7policy_create(self, l7policy):
          """Creates a new L7 policy.

          :param l7policy (object): The l7policy object.
          :return: Nothing if the create request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

      def l7policy_delete(self, l7policy):
          """Deletes an L7 policy.

          :param l7policy (object): The l7policy object.
          :return: Nothing if the delete request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          """
          raise NotImplementedError()

     def l7policy_update(self, old_l7policy, new_l7policy):
          """Updates an L7 policy.

          :param old_l7policy (object): The baseline l7policy object.
          :param new_l7policy (object): The updated l7policy object.
          :return: Nothing if the update request was accepted.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: if driver does not support request.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
          raise NotImplementedError()

### L7 Rule

#### Create

Creates a new L7 rule for an existing L7 policy.

Octavia will pass in the L7 rule object with all requested settings.

The L7 rule will be in the `PENDING_CREATE` provisioning_status and `OFFLINE` operating_status when it is passed to the driver. The driver will be responsible for updating the provisioning status of the L7 rule to either `ACTIVE` if successfully created, or `ERROR` if not created.

The Octavia API will accept and do basic API validation of the create request from the user. The l7rule python object representing the request body will be passed to the driver create method as it was received and validated with the following exceptions:

1. The project_id will be removed, if present, as this field is now deprecated. The listener will inherit the project_id from the parent load balancer.

L7rule object

As of the writing of this specification the create l7rule object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
compare_type | string | The comparison type for the L7 rule. One of CONTAINS, ENDS_WITH, EQUAL_TO, REGEX, or STARTS_WITH.
invert | bool | When True the logic of the rule is inverted. For example, with invert True, equal to would become not equal to.
key | string | The key to use for the comparison. For example, the name of the cookie to evaluate.
l7policy_id | string | The ID of the L7 policy.
l7rule_id | string | The ID of the L7 rule.
project_id | string | ID of the project owning this resource.
type | string | The L7 rule type. One of COOKIE, FILE_TYPE, HEADER, HOST_NAME, or PATH.
value | string | The value to use for the comparison. For example, the file type to compare.

#### Delete

Deletes an existing L7 rule.

Octavia will pass in the L7 rule object as a parameter.

The L7 rule will be in the `PENDING_DELETE` provisioning_status when it is passed to the driver. The driver will notify Octavia that the delete was successful by setting the provisioning_status to `DELETED`. If the delete failed, the driver will update the provisioning_status to `ERROR`.

#### Update

Modifies an existing L7 rule using the values supplied in the l7rule object.

Octavia will pass in the original L7 rule object which is the baseline for the update, and an L7 rule object with the fields to be updated. Fields not updated by the user will contain “Unset” as defined in the data model.

As of the writing of this specification the update L7 rule object may contain the following:

Name | Type | Description
--- | --- | ---
admin_state_up | bool | Admin state: True if up, False if down.
compare_type | string | The comparison type for the L7 rule. One of CONTAINS, ENDS_WITH, EQUAL_TO, REGEX, or STARTS_WITH.
invert | bool | When True the logic of the rule is inverted. For example, with invert True, equal to would become not equal to.
key | string | The key to use for the comparison. For example, the name of the cookie to evaluate.
l7rule_id | string | The ID of the L7 rule.
type | string | The L7 rule type. One of COOKIE, FILE_TYPE, HEADER, HOST_NAME, or PATH.
value | string | The value to use for the comparison. For example, the file type to compare.

The L7 rule will be in the `PENDING_UPDATE` provisioning_status when it is passed to the driver. The driver will update the provisioning_status of the L7 rule to either `ACTIVE` if successfully updated, or `ERROR` if the update was not successful.

The driver is expected to validate that the driver supports the request. The method will then return or raise an exception if the request cannot be accepted.

Abstract class definition

    class Driver(object):
        def l7rule_create(self, l7rule):

            """Creates a new L7 rule.

            :param l7rule (object): The L7 rule object.
            :return: Nothing if the create request was accepted.
            :raises DriverError: An unexpected error occurred in the driver.
            :raises NotImplementedError: if driver does not support request.
            :raises UnsupportedOptionError: if driver does not
              support one of the configuration options.
            """
            raise NotImplementedError()

        def l7rule_delete(self, l7rule):

            """Deletes an L7 rule.

            :param l7rule (object): The L7 rule object.
            :return: Nothing if the delete request was accepted.
            :raises DriverError: An unexpected error occurred in the driver.
            :raises NotImplementedError: if driver does not support request.
            """
            raise NotImplementedError()

        def l7rule_update(self, old_l7rule, new_l7rule):

            """Updates an L7 rule.

            :param old_l7rule (object): The baseline L7 rule object.
            :param new_l7rule (object): The updated L7 rule object.
            :return: Nothing if the update request was accepted.
            :raises DriverError: An unexpected error occurred in the driver.
            :raises NotImplementedError: if driver does not support request.
            :raises UnsupportedOptionError: if driver does not
              support one of the configuration options.
            """
            raise NotImplementedError()

### Flavor

Octavia flavors are defined in a separate flavor specification. Support for flavors will be provided through two provider driver interfaces, one to query supported flavor metadata keys and another to validate that a flavor is supported. Both functions are synchronous.

#### get_supported_flavor_metadata

Retrieves a dictionary of supported flavor keys and their description. For example:

    {"topology": "The load balancer topology for the flavor. One of: SINGLE, ACTIVE_STANDBY",
     "compute_flavor": "The compute driver flavor to use for the load balancer instances"}

#### validate_flavor

Validates that the driver supports the flavor metadata dictionary.

The validate_flavor method will be passed a flavor metadata dictionary that the driver will validate. This is used when an operator uploads a new flavor that applies to the driver.

The validate_flavor method will either return or raise a `UnsupportedOptionError` exception.

Following are interface definitions for flavor support:

    def get_supported_flavor_metadata():
        """Returns a dictionary of flavor metadata keys supported by this driver.

        The returned dictionary will include key/value pairs, 'name' and
        'description.'

        :returns: The flavor metadata dictionary
        :raises DriverError: An unexpected error occurred in the driver.
        :raises NotImplementedError: The driver does not support flavors.
        """
        raise NotImplementedError()

    def validate_flavor(flavor_metadata):
        """Validates if driver can support flavor as defined in flavor_metadata.

        :param flavor_metadata (dict): Dictionary with flavor metadata.
        :return: Nothing if the flavor is valid and supported.
        :raises DriverError: An unexpected error occurred in the driver.
        :raises NotImplementedError: The driver does not support flavors.
        :raises UnsupportedOptionError: if driver does not
              support one of the configuration options.
        """
        raise NotImplementedError()

### Availability Zone

Octavia availability zones have no explicit spec, but are modeled closely after the existing flavor specification. Support for availability_zones will be provided through two provider driver interfaces, one to query supported availability zone metadata keys and another to validate that an availability zone is supported. Both functions are synchronous.

#### get_supported_availability_zone_metadata

Retrieves a dictionary of supported availability zone keys and their description. For example:

    {"compute_zone": "The compute availability zone to use for this loadbalancer.",
     "management_network": "The management network ID for the loadbalancer.",
     "valid_vip_networks": "List of network IDs that are allowed for VIP use. This overrides/replaces the list of allowed networks configured in `octavia.conf`."}

#### validate_availability_zone

Validates that the driver supports the availability zone metadata dictionary.

The validate_availability_zone method will be passed an availability zone metadata dictionary that the driver will validate. This is used when an operator uploads a new availability zone that applies to the driver.

The validate_availability_zone method will either return or raise a `UnsupportedOptionError` exception.

Following are interface definitions for availability zone support:

    def get_supported_availability_zone_metadata():
        """Returns a dict of supported availability zone metadata keys.

          The returned dictionary will include key/value pairs, 'name' and
          'description.'

          :returns: The availability zone metadata dictionary
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: The driver does not support AZs.
          """
        raise NotImplementedError()

    def validate_availability_zone(availability_zone_metadata):
        """Validates if driver can support the availability zone.

          :param availability_zone_metadata: Dictionary with az metadata.
          :type availability_zone_metadata: dict
          :return: Nothing if the availability zone is valid and supported.
          :raises DriverError: An unexpected error occurred in the driver.
          :raises NotImplementedError: The driver does not support availability
            zones.
          :raises UnsupportedOptionError: if driver does not
            support one of the configuration options.
          """
        raise NotImplementedError()

### Exception Model

#### DriverError

This is a catch all exception that drivers can return if there is an unexpected error. An example might be a delete call for a load balancer the driver does not recognize. This exception includes two strings: The user fault string and the optional operator fault string. The user fault string, “user_fault_string”, will be provided to the API requester. The operator fault string, “operator_fault_string”, will be logged in the Octavia API log file for the operator to use when debugging.

    class DriverError(Exception):
        user_fault_string = _("An unknown driver error occurred.")
        operator_fault_string = _("An unknown driver error occurred.")

        def __init__(self, *args, **kwargs):
            self.user_fault_string = kwargs.pop('user_fault_string',
                                                self.user_fault_string)
            self.operator_fault_string = kwargs.pop('operator_fault_string',
                                                    self.operator_fault_string)

            super(DriverError, self).__init__(*args, **kwargs)

#### NotImplementedError

Driver implementations may not support all operations, and are free to reject a request. If the driver does not implement an API function, the driver will raise a NotImplementedError exception.

    class NotImplementedError(Exception):
        user_fault_string = _("A feature is not implemented by this driver.")
        operator_fault_string = _("A feature is not implemented by this driver.")

        def __init__(self, *args, **kwargs):
            self.user_fault_string = kwargs.pop('user_fault_string',
                                                self.user_fault_string)
            self.operator_fault_string = kwargs.pop('operator_fault_string',
                                                    self.operator_fault_string)

            super(NotImplementedError, self).__init__(*args, **kwargs)

#### UnsupportedOptionError

Provider drivers will validate that they can complete the request – that all options are supported by the driver. If the request fails validation, drivers will raise an UnsupportedOptionError exception. For example, if a driver does not support a flavor passed as an option to load balancer create(), the driver will raise an UnsupportedOptionError and include a message parameter providing an explanation of the failure.

    class UnsupportedOptionError(Exception):
        user_fault_string = _("A specified option is not supported by this driver.")
        operator_fault_string = _("A specified option is not supported by this driver.")

        def __init__(self, *args, **kwargs):
            self.user_fault_string = kwargs.pop('user_fault_string',
                                                self.user_fault_string)
            self.operator_fault_string = kwargs.pop('operator_fault_string',
                                                    self.operator_fault_string)

            super(UnsupportedOptionError, self).__init__(*args, **kwargs)

## Driver Support Library

Provider drivers need support for updating provisioning status, operating status, and statistics. Drivers will not directly use database operations, and instead will callback to octavia-lib using a new API.

Warning

The methods listed here are the only callable methods for drivers. All other interfaces are not considered stable or safe for drivers to access. See Stable Provider Driver Interface for a list of acceptable APIs for provider driver use.

Warning

This library is interim and will be removed when the driver support endpoint is made available. At which point drivers will not import any code from octavia-lib.

### Update Provisioning and Operating Status API

The update status API defined below can be used by provider drivers to update the provisioning and/or operating status of Octavia resources (load balancer, listener, pool, member, health monitor, L7 policy, or L7 rule).

For the following status API, valid values for provisioning status and operating status parameters are as defined by Octavia status codes. If an existing object is not included in the input parameter, the status remains unchanged.

Note

If the driver-agent exceeds its configured status_max_processes this call may block while it waits for a status process slot to become available. The operator will be notified if the driver-agent approaches or reaches the configured limit.

provisioning_status: status associated with lifecycle of the resource. See Octavia Provisioning Status Codes.

operating_status: the observed status of the resource. See Octavia Operating Status Codes.

The dictionary takes this form:

    { "loadbalancers": [{"id": "123",
                         "provisioning_status": "ACTIVE",
                         "operating_status": "ONLINE"},...],
      "healthmonitors": [],
      "l7policies": [],
      "l7rules": [],
      "listeners": [],
      "members": [],
      "pools": []
    }

    def update_loadbalancer_status(status):
        """Update load balancer status.

        :param status (dict): dictionary defining the provisioning status and
            operating status for load balancer objects, including pools,
            members, listeners, L7 policies, and L7 rules.
        :raises: UpdateStatusError
        :returns: None
        """

### Update Statistics API

Provider drivers can update statistics for listeners using the following API. Similar to the status function above, a single dictionary with multiple listener statistics is used to update statistics in a single call. If an existing listener is not included, the statistics that object remain unchanged.

Note

If the driver-agent exceeds its configured stats_max_processes this call may block while it waits for a stats process slot to become available. The operator will be notified if the driver-agent approaches or reaches the configured limit.

The general form of the input dictionary is a list of listener statistics:

    { "listeners": [{"id": "123",
                         "active_connections": 12,
                         "bytes_in": 238908,
                         "bytes_out": 290234,
                         "request_errors": 0,
                         "total_connections": 3530},...]
    }

    def update_listener_statistics(statistics):
        """Update listener statistics.

        :param statistics (dict): Statistics for listeners:
              id (string): ID of the listener.
              active_connections (int): Number of currently active connections.
              bytes_in (int): Total bytes received.
              bytes_out (int): Total bytes sent.
              request_errors (int): Total requests not fulfilled.
              total_connections (int): The total connections handled.
        :raises: UpdateStatisticsError
        :returns: None
        """

### Get Resource Support

Provider drivers may need to get information about an Octavia resource. As an example of its use, a provider driver may need to sync with Octavia, and therefore need to fetch all of the Octavia resources it is responsible for managing. Provider drivers can use the existing Octavia API to get these resources. See the Octavia API Reference.

### API Exception Model

The driver support API will include exceptions: two API groups:

- UpdateStatusError
- UpdateStatisticsError
- DriverAgentNotFound
- DriverAgentTimeout

Each exception class will include a message field that describes the error and references to the failed record if available.

    class UpdateStatusError(Exception):
        fault_string = _("The status update had an unknown error.")
        status_object = None
        status_object_id = None
        status_record = None

        def __init__(self, *args, **kwargs):
            self.fault_string = kwargs.pop('fault_string',
                                           self.fault_string)
            self.status_object = kwargs.pop('status_object', None)
            self.status_object_id = kwargs.pop('status_object_id', None)
            self.status_record = kwargs.pop('status_record', None)

            super(UpdateStatusError, self).__init__(self.fault_string,
                                                    *args, **kwargs)

    class UpdateStatisticsError(Exception):
        fault_string = _("The statistics update had an unknown error.")
        stats_object = None
        stats_object_id = None
        stats_record = None

        def __init__(self, *args, **kwargs):
            self.fault_string = kwargs.pop('fault_string',
                                           self.fault_string)
            self.stats_object = kwargs.pop('stats_object', None)
            self.stats_object_id = kwargs.pop('stats_object_id', None)
            self.stats_record = kwargs.pop('stats_record', None)

            super(UpdateStatisticsError, self).__init__(self.fault_string,
                                                        *args, **kwargs)

    class DriverAgentNotFound(Exception):
      fault_string = _("The driver-agent process was not found or not ready.")

      def __init__(self, *args, **kwargs):
          self.fault_string = kwargs.pop('fault_string', self.fault_string)
          super(DriverAgentNotFound, self).__init__(self.fault_string,
                                                    *args, **kwargs)

    class DriverAgentTimeout(Exception):
      fault_string = _("The driver-agent timeout.")

      def __init__(self, *args, **kwargs):
          self.fault_string = kwargs.pop('fault_string', self.fault_string)
          super(DriverAgentTimeout, self).__init__(self.fault_string,
                                                   *args, **kwargs)

## Provider Agents

Provider agents are long-running processes started by the Octavia driver-agent process at start up. They are intended to allow provider drivers a long running process that can handle periodic jobs for the provider driver or receive events from another provider agent. Provider agents are optional and not required for a successful Octavia provider driver.

Provider Agents have access to the same Stable Provider Driver Interface as the provider driver. A provider agent must not access any other Octavia code.

Warning

The methods listed in the Driver Support Library section are the only Octavia callable methods for provider agents. All other interfaces are not considered stable or safe for provider agents to access. See Stable Provider Driver Interface for a list of acceptable APIs for provider agents use.

### Declaring Your Provider Agent

The Octavia driver-agent will use stevedore to load enabled provider agents at start up. Provider agents are enabled in the Octavia configuration file. Provider agents that are installed, but not enabled, will not be loaded. An example configuration file entry for a provider agent is:

    [driver_agent]
    enabled_provider_agents = amphora_agent, noop_agent

The provider agent name must match the provider agent name declared in your python setup tools entry point. For example:

    octavia.driver_agent.provider_agents =
        amphora_agent = octavia.api.drivers.amphora_driver.agent:AmphoraProviderAgent
        noop_agent = octavia.api.drivers.noop_driver.agent:noop_provider_agent

### Provider Agent Method Invocation

On start up of the Octavia driver-agent, the method defined in the entry point will be launched in its own multiprocessing Process.

Your provider agent method will be passed a multiprocessing Event that will be used to signal that the provider agent should shutdown. When this event is “set”, the provider agent should gracefully shutdown. If the provider agent fails to exit within the Octavia configuration file setting “provider_agent_shutdown_timeout” period, the driver-agent will forcefully shutdown the provider agent with a SIGKILL signal.

### Example Provider Agent Method

If, for example, you declared a provider agent as “my_agent”:

    octavia.driver_agent.provider_agents =
        my_agent = example_inc.drivers.my_driver.agent:my_provider_agent

The signature of your “my_provider_agent” method would be:

    def my_provider_agent(exit_event):

## Documenting the Driver

Octavia provides two documents to let operators and users know about available drivers and their features.

### Available Provider Drivers

The Available Provider Drivers document provides administrators with a guide to the available Octavia provider drivers. Since provider drivers are not included in the Octavia source repositories, this guide is an important tool for administrators to find your provider driver.

You can submit information for your provider driver by submitting a patch to the Octavia documentation following the normal OpenStack process.

See the OpenStack Contributor Guide for more information on submitting a patch to OpenStack.

### Octavia Provider Feature Matrix

The Octavia documentation includes a Octavia Provider Feature Matrix that informs users on which Octavia features are supported by each provider driver.

The feature matrices are built using the Oslo sphinx-feature-classification library. This allows a simple INI file format for describing the capabilities of an Octavia provider driver.

Each driver should define a [driver.<driver name>] section and then add a line to each feature specifying the level of support the provider driver provides for the feature.

For example, the Amphora driver support for “admin_state_up” would add the following to the feature-matrix-lb.ini file.

    [driver.amphora]
    title=Amphora Provider
    link=https://docs.openstack.org/api-ref/load-balancer/v2/index.html

    [operation.admin_state_up]
    ...
    driver.amphora=complete

Valid driver feature support statuses are:

`complete`
  Fully implemented, expected to work at all times.
`partial`
  Implemented, but with caveats about when it will work.
`missing`
  Not implemented at all.

You can also optionally provide additional, provider driver specific, notes for users by defining a “driver-notes.<driver name>”.

    [operation.admin_state_up]
    ...
    driver.amphora=complete
    driver-notes.amphora=The Amphora driver fully supports admin_state_up.

Driver notes are highly recommended when a provider driver declares a `partial` status.

this page last updated: 2020-04-10 18:17:54

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