Build gardener/gardener dev images

[oliver-goetz]

/kind enhancement

What this PR does / why we need it:
Builds gardener/gardener dev images in prow.

presubmit jobs:

• pull-gardener-verify-image-build builds all targets of Dockerfile but is not pushing the results anywhere
  • these are examples how the jobs look like in prow
• pull-gardener-publish-test-images is an optional job to build and publish images of an PR to eu.gcr.io/gardener-project/gardener
  • it it started on request in a PR /test pull-gardener-publish-test-images and takes about 5 minutes
  • these are examples how the jobs look like in prow
• Both jobs exist for release branches too pull-gardener-verify-image-build-release, pull-gardener-publish-test-images-release

postsubmit jobs:

• post-gardener-build-dev-images builds and publishes images from master branch to eu.gcr.io/gardener-project/gardener
  • is not running when only VERSION file is changed to not interfere release builds
  • these are examples how the jobs look like in prow

This approach is slightly different than the current setup, but still allows to build test images from a PR.
Another option could be changing pull-gardener-publish-test-images to a non-optional prow job, to publish images from each commit of any PR and remove pull-gardener-verify-image-build

A minor change is updating kaniko to the latest patch level 1.8.1.

Which issue(s) this PR fixes:
Fixes #180 partly

Special notes for your reviewer:
concourse-ci/publish should be deactivated in gardener/gardener when merging this PR

[timebertt]

Note: we need make councourse-ci/publish not required anymore in branch protection.

[timebertt]

/lgtm
/hold
for @oliver-goetz

[oliver-goetz]

/lgtm
/unhold

[gardener-prow]

@oliver-goetz: you cannot LGTM your own PR.

In response to this:

/lgtm
/unhold

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[gardener-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: oliver-goetz, timebertt

The full list of commands accepted by this bot can be found here.

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Needs approval from an approver in each of these files:

• OWNERS [oliver-goetz,timebertt]

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[gardener-prow]

@oliver-goetz: Updated the following 2 configmaps:

• job-config configmap in namespace prow at cluster gardener-prow-trusted using the following files:
  • key build-gardener-images.yaml using file ``
  • key gardener-build-dev-images.yaml using file config/jobs/gardener/gardener-build-dev-images.yaml
  • key gardener-test-builds.yaml using file config/jobs/gardener/gardener-test-builds.yaml
  • key gardener-build-dev-images-release.yaml using file config/jobs/gardener/release/gardener-build-dev-images-release.yaml
  • key gardener-test-builds-release.yaml using file config/jobs/gardener/release/gardener-test-builds-release.yaml
• config configmap in namespace prow at cluster gardener-prow-trusted using the following files:
  • key config.yaml using file config/prow/config.yaml

In response to this:

/kind enhancement

What this PR does / why we need it:
Builds gardener/gardener dev images in prow.

presubmit jobs:

• pull-gardener-verify-image-build builds all targets of Dockerfile but is not pushing the results anywhere
• these are examples how the jobs look like in prow
• pull-gardener-publish-test-images is an optional job to build and publish images of an PR to eu.gcr.io/gardener-project/gardener
• it it started on request in a PR /test pull-gardener-publish-test-images and takes about 5 minutes
• Both jobs exist for release branches too pull-gardener-verify-image-build-release, pull-gardener-publish-test-images-release

postsubmit jobs:

• post-gardener-build-dev-images builds and publishes images from master branch to eu.gcr.io/gardener-project/gardener
• is not running when only VERSION file is changed to not interfere release builds

This approach is slightly different than the current setup, but still allows to build test images from a PR.
Another option could be changing pull-gardener-publish-test-images to a non-optional prow job, to publish images from each commit of any PR and remove pull-gardener-verify-image-build

A minor change is updating kaniko to the latest patch level 1.8.1.

Which issue(s) this PR fixes:
Fixes #180 partly

Special notes for your reviewer:
concourse-ci/publish should be deactivated in gardener/gardener when merging this PR

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.