Add org.opencontainers.image.* labels to Dockerfiles

[marccarre]

Why? What?

• This should ultimately help for image-to-code back references.
  See also: https://trello.com/c/wJv5EP8b/126-image-to-code-back-references
• org.label-schema.* labels are now deprecated, in favour of org.opencontainers.image.* labels.
  See also: https://github.com/opencontainers/image-spec/blob/master/annotations.md#back-compatibility-with-label-schema
• MAINTAINER is deprecated, in favour of the maintainer label.
• Git revision (git rev-parse --short HEAD) is now injected at docker build time.

Testing:

$ docker inspect quay.io/weaveworks/users
[
    {
        [...]
        "ContainerConfig": {
            [...]
            "Labels": {
                "maintainer": "Weaveworks <[email protected]>",
                "org.opencontainers.image.revision": "3df5592",
                "org.opencontainers.image.source": "https://github.com/weaveworks/service/tree/master/users",
                "org.opencontainers.image.title": "users",
                "org.opencontainers.image.vendor": "Weaveworks"
            }
[...]

Related to:

• Inject long git revision in Dockerfiles #2027
• weaveworks/service-ui/pull/2523
• weaveworks/service-conf/pull/2231
• Add opencontainers labels to dockerfiles build-tools#132
• Add org.opencontainers.image.* labels to Dockerfiles kubediff#55
• weaveworks/launch-generator/pull/290
• weaveworks/launch-generator/pull/291
• Add org.opencontainers.image.* labels to Dockerfiles grafanalib#127
• Add org.opencontainers.image.* labels to Dockerfiles fluxcd/flux#1075
• Add org.opencontainers.image.* labels to Dockerfiles weave#3299
• Add org.opencontainers.image.* labels to Dockerfiles cortexproject/cortex#825
• Add org.opencontainers.image.* labels to Dockerfiles scope#3171
• Add org.opencontainers.image.* labels to Dockerfiles launcher#195
• https://trello.com/c/wJv5EP8b/126-image-to-code-back-references

[marccarre]

FYI: I'll make similar changes to all other repositories/Dockerfiles soonish.