octavia/specs/version1.1/enable-provider-driver.rst

Enable Provider Driver Support

Specification Table of Contents

https://storyboard.openstack.org/#!/story/1655768

Provider drivers are implementations that give Octavia operators a choice of which load balancing systems to use in their Octavia deployment. Currently, the default Octavia driver is the only one available. Operators may want to employ other load balancing implementations, including hardware appliances, in addition to the default Octavia driver.

Problem description

Neutron LBaaS v2 supports a provider parameter, giving LBaaS users a way to direct LBaaS requests to a specific backend driver. The Octavia API includes a provider parameter as well, but currently supports one provider, the Octavia driver. Adding support for other drivers is needed. With this in place, operators can configure load balancers using multiple providers, either the Octavia default or others.

Proposed change

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.

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:

octavia = octavia.api.drivers.octavia.driver:OctaviaDriver

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 <https://developer.openstack.org/api-ref/load-balancer/v2/index.html> 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.
  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.

  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 pkcs12 format.
  3. The sni_container_refs will be expanded and provided to the driver in pkcs12 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.
  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.
  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.

  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.
  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.

  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.

  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.
  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.

  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.
  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, or SOURCE_IP.
  loadbalancer_id	string	ID of load balancer.
  members	list	A list of Member objects.
  name	string	Human-readable name of the pool.
  pool_id	string	ID of pool to create.
  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>}

• 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.

  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.
  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>}

  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.
  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.

  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, members):
      """Creates, updates, or deletes a set of pool members.

      :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.
  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.
  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.
  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, or TLS-HELLO.
  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.

  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.
  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.
  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.
  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_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.

  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_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_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.
  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.

  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 specification (see References below). 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_keys

  Retrieves a dictionary of supported flavor keys and their description.

  {"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()

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 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.

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.

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
    """
    raise NotImplementedError()

Update statistics API

Provider drivers can update statistics for load balancers and listeners using the following API. Similar to the status function above, a single dictionary with multiple load balancer and/or listener statistics is used to update statistics in a single call. If an existing load balancer or listener is not included, the statistics those objects remain unchanged.

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

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

def update_loadbalancer_statistics(statistics):
    """Update load balancer statistics.

    :param statistics (dict): Statistics for loadbalancers and listeners:
          id (string): ID for load balancer or 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
    """
    raise NotImplementedError()

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 two Exceptions, one for each of the two API groups:

• UpdateStatusError
• UpdateStatisticsError

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

Alternatives

Driver Support Library

An alternative to this library is a REST interface that drivers use directly. A REST implementation can still be used within the library, but wrapping it in an API simplifies the programming interface.

Data model impact

None, the required data model changes are already present.

REST API impact

None, the required REST API changes are already present.

Security impact

None.

Notifications impact

None.

Other end user impact

Users will be able to direct requests to specific backends using the provider parameter. Users may want to understand the availability of provider drivers, and can use Octavia APIs to do so.

Performance Impact

The performance impact on Octavia should be minimal. Driver requests will need to be scheduled, and Octavia will process driver callbacks through a REST interface. As provider drivers are loaded by Octavia, calls into drivers are through direct interfaces.

Other deployer impact

Minimal configuration is needed to support provider drivers. The work required is adding a driver name to Octavia's configuration file, and installing provider drivers supplied by third parties.

Developer impact

The proposal defines interaction between Octavia and backend drivers, so no developer impact is expected.

Implementation

Assignee(s)

Work Items

• Implement loading drivers defined the Octavia configuration.
• Implement scheduling requests to drivers.
• Implement validating flavors with provider drivers.
• Implement getting and testing flavors with provider drivers.
• Implement a no-op driver for testing.
• Implement driver support library functions:
  • Update status functions
  • Update statistics functions
• Migrate the existing Octavia reference driver to use this interface.

Dependencies

• Octavia API: https://developer.openstack.org/api-ref/load-balancer/
• Flavors: https://docs.openstack.org/octavia/latest/contributor/specs/version1.0/flavors.html

Testing

Tempest tests should be added for testing:

• Scheduling: test that Octavia effectively schedules to drivers besides the default driver.
• Request validation: test request validation API.
• Flavor profile validation: test flavor validation.
• Flavor queries: test flavor queries.
• Statistics updates

Functional API tests should be updated to test the provider API.

Documentation Impact

A driver developer guide should be created.

References

Octavia API

https://developer.openstack.org/api-ref/load-balancer/v2/index.html

Octavia Flavors Specification

https://docs.openstack.org/octavia/latest/contributor/specs/version1.0/flavors.html