.. _CONTRIBUTING: ================= How To Contribute ================= Basics ====== #. Our source code is hosted on `OpenStack Kolla Git`_. Bugs should be filed on launchpad_. #. Please follow OpenStack `Gerrit Workflow`_ to to contribute to Kolla. #. Note the branch you're proposing changes to. ``master`` is the current focus of development. Kolla project has a strict policy of only allowing backports in ``stable/branch``, unless when not applicable. A bug in a ``stable/branch`` will first have to be fixed in ``master``. #. Please file a launchpad_ blueprint for any significant code change and a bug for any significant bug fix or add a TrivialFix tag for simple changes. See how to reference a bug or a blueprint in the commit message here_ #. TrivialFix tags or bugs are not required for documentation changes. .. _OpenStack Kolla Git: https://git.openstack.org/cgit/openstack/kolla/ .. _launchpad: https://bugs.launchpad.net/kolla .. _here: https://wiki.openstack.org/wiki/GitCommitMessages Development Environment ======================= Please follow our `quickstart`_ to deploy your environment and test your changes. .. _quickstart: http://docs.openstack.org/developer/kolla/quickstart.html Please use the existing sandbox repository, available at https://git.openstack.org/cgit/openstack-dev/sandbox, for learning, understanding and testing the `Gerrit Workflow`_. .. _Gerrit Workflow: http://docs.openstack.org/infra/manual/developers.html#development-workflow Adding a new service ==================== Kolla aims to both containerise and deploy all services within the OpenStack "big tent". This is a constantly moving target as the ecosystem grows, so these guidelines aim to help make adding a new service to Kolla a smooth experience. The image --------- Kolla follows Docker best practices (https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/) when designing and implementing services where at all possible. We use ``jinja2`` templating syntax to help manage the volume and complexity that comes with maintaining multiple Dockerfiles for multiple different base operating systems. Images should be created under the ``docker`` directory. OpenStack services should inherit from the provided ``openstack-base`` image, while supporting and infrastructure services (e.g. mongodb) should inherit from ``base``. Services consisting of only one service should be placed in an image named the same as that service, e.g. ``horizon``. Services that consist of multiple processes generally use a base image and child images, e.g. ``glance-base``, ``glance-api``, and ``glance-registry``. Jinja2 'blocks' are employed throughout the Dockerfile's to help operators customise various stages of the build (refer to http://docs.openstack.org/developer/kolla/image-building.html?highlight=override#dockerfile-customisation) Some of these blocks are free form however, there are a subset that should be common to every Dockerfile. The overall structure for a multi container service is as follows:: FROM {{ namespace }}/{{ image_prefix }}openstack-base:{{ tag }} MAINTAINER {{ maintainer }} {% import "macros.j2" as macros with context %} << binary specific steps >> << source specific steps >> << common steps >> {% block << service >>_footer %}{% endblock %} {% block footer %}{% endblock %} {{ include_footer }} .. NOTE:: The generic footer block ``{% block footer %}{% endblock %}`` should not be included in base images (e.g. glance-base). {{ include_footer }} is legacy and should not be included in new services, it is superseded by {% block footer %}{% endblock %} Orchestration ------------- As of the Newton release there are two main orchestration methods in existence for Kolla, Ansible and Kubernetes. Ansible is the most mature and generally regarded as the reference implementation. When adding a role for a new service in Ansible, there are couple of patterns that Kolla uses throughout that should be followed. * The sample inventories Entries should be added for the service in each of ``ansible/inventory/multinode`` and ``ansible/inventory/all-in-one``. * The playbook The main playbook that ties all roles together is in ``ansible/site.yml``, this should be updated with appropriate roles, tags, and conditions. Ensure also that supporting hosts such as haproxy are updated when necessary. * The common role A ``common`` role exists which sets up logging, ``kolla-toolbox`` and other supporting components. This should be included in all services within ``meta/main.yml`` of your role. * Common tasks All services should include the following tasks: - ``do_reconfigure.yml`` : Used to push new configuration files to the host and restart the service. - ``pull.yml`` : Used to pre fetch the image into the Docker image cache on hosts, to speed up intial deploys. - ``upgrade.yml`` : Used for upgrading the service in a rolling fashion. May include service specific setup and steps as not all services can be upgraded in the same way. * Log delivery - For OpenStack services the service has be added oo the ``file_match`` paramater in the ``openstack_logstreamer_input`` section in the ``heka-openstack.toml.j2`` template file in ``ansible/roles/comm/templates`` to deliver log messages to Elasticsearch. * Logrotation - For OpenStack services there should be a ``cron-logrotate-PROJECT.conf.j2`` template file in ``ansible/roles/common/templates`` with the following content: .. code:: "/var/log/kolla/PROJECT/*.log" { } - For OpenStack services there should be a entry in the ``services`` list in the ``cron.json.j2`` template file in ``ansible/roles/common/templates``. Other than the above, most roles follow the following pattern: - ``Register``: Involves registering the service with Keystone, creating endpoints, roles, users, etc. - ``Config``: Distributes the config files to the nodes to be pulled into the container on startup. - ``Bootstrap``: Creating the database (but not tables), database user for the service, permissions, etc. - ``Bootstrap Service``: Starts a one shot container on the host to create the database tables, and other initial run time config. - ``Start``: Start the service(s).