Migrate to quay.io

[abesto]

Why

• pro
  • Building on Docker Hub is requires a lot of manual clicking, because Docker Hub doesn't support automatically translating git tags to docker tags (https://github.com/docker/hub-beta-feedback/issues/165)
  • The UI is a pain to use, making the previous point even worse.
  • Building on the first push of a tag currently seems to not work, the builds are just not started.
  • Quay.io has a great API, with great documentation at http://docs.quay.io/api/swagger/. The API of Docker Hub is basically just the standard docker API, limiting our options in automation (no endpoint to query build status for example)
  • The Quay.io UI supports firing a specific build trigger (like "pretend 1.4.0-quay.io was just pushed") to re-build in case of intermittent failures, while Docker Hub UI only supports triggering all the build configurations.
• con
  • Any projects / people already using the docker images will need to update to the new images (the image names will look like quay.io/opnezipkin/zipkin-collector:1.4.0 instead of openzipkin/zipkin-collector:1.4.0
  • Docker Hub is the official, default docker registry.
  • Docker Hub will probably be supported as long as Docker, the company exists. Quay.io might only be supported until CoreOS exists.
  • The UI is great, when it works; sometimes it needs time or a few reloads (can be mitigated by automation)

    How

Docker Hub supports dependent builds but doesn't support automatic docker tags from git tags. Quay.io supports automatic docker tags, but not dependent builds. We use the former to simulate the latter by starting zipkin-base with tags like base-1.4.0, and building FROM that tag in the other images; the images to be used by our users will still be versioned normally, with tags like 1.4.0.

Example

By pushing base-1.4.0 I started this zipkin-base build, creating the docker tag base-1.4.0 on zipkin-base. Then I updated the Dockerfiles and pushed the tag 1.4.0-quay.io (if we choose to migrate, we'd of course drop the qualifier). This started builds for the rest of the services, creating the docker tag 1.4.0-quay.io, like here.

[codefromthecrypt]

LGTM thanks for streamlining things. We'll need to warn users about the repo change until we have a process down to push "major" versions to dockerhub.

[abesto]

Closing this, will open another PR where the process is automated.