1. devstack
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Document where we are going

Somewhat opinionated document on where we want to be going, should be
an accurate first approximation of what Dean and I have chatted about
over the last few weeks. Hopefully helpful in framing where we are
going.

Change-Id: Ia153af27a08203ffc44e37c7db73e04573d3be9f

Sean Dague authored on 2015/01/28 23:29:03
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FUTURE.rst
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+=============
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+ Quo Vadimus
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+=============
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+
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+Where are we going?
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+
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+This is a document in Devstack to outline where we are headed in the
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+future. The future might be near or far, but this is where we'd like
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+to be.
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+
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+This is intended to help people contribute, because it will be a
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+little clearer if a contribution takes us closer to or further away to
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+our end game.
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+
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+==================
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+ Default Services
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+==================
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+
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+Devstack is designed as a development environment first. There are a
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+lot of ways to compose the OpenStack services, but we do need one
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+default.
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+
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+That should be the Compute Layer (currently Glance + Nova + Cinder +
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+Neutron Core (not advanced services) + Keystone). It should be the
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+base building block going forward, and the introduction point of
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+people to OpenStack via Devstack.
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+
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+================
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+ Service Howtos
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+================
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+
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+Starting from the base building block all services included in
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+OpenStack should have an overview page in the Devstack
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+documentation. That should include the following:
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+
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+- A helpful high level overview of that service
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+- What it depends on (both other OpenStack services and other system
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+  components)
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+- What new daemons are needed to be started, including where they
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+  should live
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+
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+This provides a map for people doing multinode testing to understand
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+what portions are control plane, which should live on worker nodes.
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+
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+Service how to pages will start with an ugly "This team has provided
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+no information about this service" until someone does.
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+
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+===================
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+ Included Services
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+===================
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+
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+Devstack doesn't need to eat the world. Given the existence of the
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+external devstack plugin architecture, the future direction is to move
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+the bulk of the support code out of devstack itself and into external
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+plugins.
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+
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+This will also promote a more clean separation between services.
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+
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+=============================
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+ Included Backends / Drivers
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+=============================
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+
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+Upstream Devstack should only include Open Source backends / drivers,
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+it's intent is for Open Source development of OpenStack. Proprietary
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+drivers should be supported via external plugins.
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+
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+Just being Open Source doesn't mean it should be in upstream Devstack
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+if it's not required for base development of OpenStack
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+components. When in doubt, external plugins should be used.
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+
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+========================================
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+ OpenStack Services vs. System Services
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+========================================
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+
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+ENABLED_SERVICES is currently entirely too overloaded. We should have
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+a separation of actual OpenStack services that you have to run (n-cpu,
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+g-api) and required backends like mysql and rabbitmq.
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+
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+===========================
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+ Splitting up of Functions
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+===========================
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+
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+The functions-common file has grown over time, and needs to be split
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+up into smaller libraries that handle specific domains.
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+
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+======================
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+ Testing of Functions
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+======================
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+
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+Every function in a functions file should get tests. The devstack
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+testing framework is young, but we do have some unit tests for the
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+tree, and those should be enhanced.
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+
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+==============================
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+ Not Co-Gating with the World
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+==============================
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+
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+As projects spin up functional test jobs, Devstack should not be
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+co-gated with every single one of those. The Devstack team has one of
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+the fastest turn arounds for blocking bugs of any Open Stack
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+project.
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+
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+Basic service validation should be included as part of Devstack
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+installation to mitigate this.
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+
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+============================
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+ Documenting all the things
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+============================
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+
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+Devstack started off as an explanation as much as an install
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+script. We would love contributions to that further enhance the
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+comments and explanations about what is happening, even if it seems a
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+little pedantic at times.