Support IPv6-Only Deployments

Support IPv6-Only Deployments

For years now, OpenStack has included and continually tested features for providing IPv6-ready environments, to the point where we’ve also seen interest in operating environments which have no traditional IPv4 at all. As a result, we need tests which can confirm this scenario also works well and does not regress.

This community wide goal cover the below scenarios:

  1. OpenStack services (include mysql, rabbitmq etc) listen and communicate with each other on only IPv6.

  2. OpenStack booted VMs can communicate (to other VMs or OpenStack service endpoint) over only IPv6. This scenario is much needed when OpenStack services like Octavia and Sahara need to communicate to other services from compute VM.

In most of the cases, above two scenarios might work fine but there is insufficient testing to prove it. The purpose of this goal is to add the integration testing of IPv6-only support setting for all the projects and adding the IPv6 support for inter-service communication where it doesn’t exist. This way we can at least make sure that OpenStack services work fine on IPv6-only environment.

Note

Covering all the possible IPv6 scenarios and testing all projects resources, backend vendors driver or hardware is out of the scope of this goal. That might need more work and a large number of testing across all projects with various drivers. Each project team should encourage their vendors and partners to head in the direction of ipv6 native operation. This goal may also entail the drafting of new standards such as a v6 equivalent for metadata services which popular clients can eventually implement.

Below are the next steps for respective team to extend the IPv6 testing scope or documentation:

  1. Encourage vendors/backends to extend the IPv6-only testing as per their specific scenarios and use cases. Corresponding Project team can choose to document the same if any limitation over their supported backends.

  2. OpenStack Deployment projects, can target to deploy the OpenStack using IPv6-only environment.

Note

The above listed work is specific to few projects and not applicable for all the OpenStack projects so these are out of scope if this goal and good to extend as per project requirement and scope.

Champion

Ghanshyam Mann(gmann) <gmann@ghanshyammann.com> has volunteered to drive this goal.

Gerrit Topic

To facilitate tracking commits related to this goal should use the gerrit topic:

IPv6-support-and-testing

Completion Criteria

In order for a project to call this goal complete it must:

  1. All Devstack plugins should use the standard variable like SERVICE_HOST, SERVICE_LISTEN_ADDRESS to create the service endpoint or service listen address. Devstack plugins should not use any hard-coded value or any other variables not adjusted by devstack when it is configured for IPv6.

  2. Run the voting integration job with IPv6-only setting (or through supervision which will fail the job if intra-stack communication attempts to utilize IP version 4 protocol) in check and gate pipeline. This job will be suffixed as -IPv6-only. This integration job does not need to run all the tests present (or running in other integration jobs) in that project. The set of tests to run on these jobs will be decided on runtime based on each project requirement and considering the two scenarios listed above under the scope of this goal. For example:

    • New IPv6-only Tempest job can install devstack with default services with IPv6-only mode and run the IPv6 related tests only.

    • Or have a single integrated tempest job install devstack with all services enabled and tests their endpoints etc.

IPv6 setting on Devstack and Devstack plugins

Devstack already has IPv6 setting support. Setting the SERVICE_IP_VERSION=6 and not setting the SERVICE_HOST in local.conf will make projects to configure their services to listen and create keystone endpoint on IPv6.

DevStack workflow:

  1. If SERVICE_IP_VERSION == ‘6’ then, devstack sets the SERVICE_HOST to HOST_IPv6 (if SERVICE_HOST is not set explicitly) and SERVICE_LISTEN_ADDRESS to [::] and other settings too.

  2. Each project will use the SERVICE_HOST to create their service endpoint with this address.

The above setting make sure each service listen and communicate over IPv6. These settings are confirmed for all six services which are configured by devstack. We hope all the devstack-plugins also follow the same setting which means use SERVICE_HOST to create the endpoints. If not, we then need to add that support on that project’s devstack-plugin. One example of missing this setting is in senlin’s devstack plugin (as of drafting this goal) which directly use HOST_IP as listen address so setting the SERVICE_IP_VERSION=6 does not make senlin to listen on IPv6 - https://opendev.org/openstack/senlin/src/commit/f4a00ff076df16591ef3cd073f51f42405d2c34c/devstack/lib/senlin#L44

Gate jobs for IPv6-only setting

  • devstack-IPv6 This base job already exists and configures devstack for IPv6-only setting. This base job set SERVICE_HOST: "" to make SERVICE_IP_VERSION: 6 working. If SERVICE_HOST is not reset or overridden by any derived job then SERVICE_IP_VERSION: 6 has no effect.

  • All *-IPv6-only integration jobs will use the devstack base job as parent.

  • Tempest will provide the IPv6-only integration job which can be added in integrated-gate template.

References

Devstack has base job ready to use.

Tempest run the Tempest IPv6 job running but as non voting.

Oslo utils common netutils to use for IPv6 settings and checks.

Reference of this goal idea in community-goals etherpad(#14).

Current State / Anticipated Impact

Most projects work fine with IPv6 already, but there is no testing to confirm IPv6-only functionality and to avoid any breaking change to merge. By having a voting job running IPv6-only setting (or failing on any v4 communication which hasn’t been whitelisted) will make sure we have the IPv6-only scenario working and will not regress.

Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.