helm-hashtag

helm-hashtag

This plugin stores the docker digest hash of tags locally, as to avoid max tags limitations on 3rd party registries.

The source of truth has to be a Google Container Registry, it is assumed that one repository will be used to lookup digests for all overrides.

Usage

The values file needs to contain docker images and tags in the following format:

chart-name-here:
  image:
    repository: eu.gcr.io/foobar/imagename
    tag: foobar

The above value will then be overridden with:

chart-name-here:
  image:
    repository: eu.gcr.io/foobar/imagename@sha256
    tag: <long digest hash>

And stored into a the "hashtag" value file.

Which can then be used as helm values, helm install -f <original-values.yaml> -f <hashtag-values.yaml> ...

Add the repository to the hashtag.yaml

chart-name-here:
  image: null

# Install the plugin
$ helm plugin install https://github.com/balboah/helm-hashtag --version master

# Update tag hash digest values
$ helm hashtag -f values.yaml --tagfile hashtags.yaml --resolver="https://foobar/path"

# Use the override values
$ helm install -f values.yaml -f hashtags.yaml ...

Resolver format:

The resolver is any http server which serves the correct format.

http GET <resolver-url>/<image>/<tag>

some-other-registry.com/foobar/my-image@sha256:7639a940c07f15c0f842faccd2f0973da9875f02ac1139b72a704e206bdc4e8c
eu.gcr.io/foobar/my-image@sha256:3867e93f2ad17b12cda5e4dede5c21311826de2b022ab65804e53de3c401b7a1

This file content can be generated with:

docker inspect eu.gcr.io/foobar/my-image:tagname -f '{{range .RepoDigests}}{{. | printf "%s\n"}}{{end}}'

Which could be saved in Google Cloud Storage to be used as the resolver:

docker inspect eu.gcr.io/foobar/my-image:tagname -f '{{range .RepoDigests}}{{. | printf "%s\n"}}{{end}}' \
  | gsutil cp - gs://your-bucket-of-tags/my-image/tagname

This will typically be ran in the CI platform that creates the original image.