Sinker

sinker syncs container images from one registry to another. This is useful in cases where you need to have images that exist in a public container registry, in a private one.

See the example folder for more details on the produced files.

Installation

GO111MODULE=on go get github.com/plexsystems/sinker

Releases are also provided in the releases tab on GitHub.

The image manifest

All commands either create, update, or read from the image manifest (.images.yaml).

While the create and update commands assist with managing the image manifest, the push command will not modify the image manifest. Allowing you to manually control the manifest if desired.

The target section

target:
    registry: mycompany.com
    repository: myteam

The target section is where all of the images will be synced to. The above yaml would sync all images to the mycompany registry in the myteam repository: mycompany.com/myteam/....

The repository field is optional.

The images section

target:
    registry: mycompany.com
    repository: myteam
images:
  - repository: coreos/prometheus-operator
    version: v0.40.0
    source: quay.io
  - repository: jimmidyson/configmap-reload
    version: v0.3.1
    source: docker.io
  - repository: super/secret
    version: v1.0.0
    source: privatecompany.org
    auth:
        username: USER_ENVIRONMENT_VARIABLE_NAME
        password: PASSWORD_ENVIRONMENT_VARIABLE_NAME

The images section includes the source registry and the repository for the image. During a sync, an image push would result in mycompany.com/myteam/coreos/prometheus-operator:v0.40.0

Auth

All auth is handled by looking at the clients Docker auth. If the client can perform a docker push or docker pull, sinker will be able to as well.

In the event that an image that needs to be sync'd is in another registry, the auth section allows you to set the names of environment variables that will be used for creating basic auth to the registry. This is useful in CI pipelines.

Usage

All examples are taken from running commands in the examples/ folder.

Create command

Create an image manifest that includes a target registry and a collection of images that should be synced to the target.

$ sinker create --target mycompany.com/myteam

--target flag (required)

Specifies the target registry (and optionally a repository) to sync the images to

--autodetect flag (optional)

While this tool is not Kubernetes specific, currently the create and update commands find all Kubernetes manifests and extracts the image references from them. This includes images specified in container arguments as well as CRDs such as Prometheus and Alertmanager.

$ sinker create --target mycompany.com/myteam --autodetect

target:
    registry: mycompany.com
    repository: myteam
images:
  - repository: coreos/prometheus-operator
    version: v0.40.0
    source: quay.io
  - repository: jimmidyson/configmap-reload
    version: v0.3.1
    source: docker.io
  - repository: coreos/prometheus-config-reloader
    version: v0.40.0
    source: quay.io

Push command

Push all of the images inside of the image manifest to the target registry.

$ sinker push

--dryrun flag (optional)

The --dryrun flag will print out a summary of the images that do not exist at the target registry and the fully qualified names of the images that will be pushed.

Update command

$ sinker update

Updates the current manifest to reflect new changes to Kubernetes manifests.

NOTE: The update command will ONLY update image versions. This allows for pinning of certain fields you want to manage yourself (source registry, auth)

--target flag (optional)

If desired, you can set a new target in the image manifest by using --target during an update.

List command

$ sinker list target

Prints a list of either the source or target images. This can be useful for piping into additional tooling that acts on image urls.

--output flag (optional)

Outputs the list to a file (e.g. images.txt)

Check command

$ sinker check

Checks if any of the images found in the image manifest have new updates. Currently only works for the source images that are hosted on Docker Hub.