JARVICE Cache Pull

Kubernetes daemon set for JARVICE docker image cache

Getting Started

This project will build and deploy jarvice-cache-pull daemonset for JARVICE

Prerequisites

This project requires:

• kubectl
• docker
• ssh

Note remote access to ppc64le host required (with same prerequisites as above)

For Ubuntu:

apt-get install ssh snapd
snap install kubectl --classic
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
DEBARCH=$(dpkg --print-architecture) && echo "deb [arch=$DEBARCH] https://download.docker.com/linux/ubuntu ${LSB_REL_NAME} stable" > /etc/apt/sources.list.d/docker.list
apt-get update && apt-get install docker-ce

Building

The build-docker.sh script is used to build the required Docker images and create a multi-arch manifest list.

Required arguments:

• -h <ppc64le-host> := username and host for remote ppc64le host (e.g. khill@ppc64le.example.org)
• -r <docker-repo> := Docker repository for project (e.g. quay.io/khill/jarvice-cache-pull)
• -R <docker-registry> := Docker registry (e.g. quay.io)
• -u <docker-user> := Docker registry username
• -U <ubuntu-release> := Ubuntu release for Docker image (e.g. bionic)
• -g <github-repo> := GitHub repository for this project (e.g. github.com/nimbix/jarvice-cache-pull)
• -t <github-token> := GitHub username and access token (e.g. khill:<token>)

Deployment

This daemon set uses K8s Config Map and secrets to configure which Docker images to pull into a workers cache. The config map image-cache list the desired Docker images to cache using json format.

The default Docker secret used is jarvice-docker. Additional Docker secrets can be added following these instructions

Image Cache Format

The image-cache Config Map consist of a json file and interval literal:

Image Object

Key	Value	Description
ref	string	Name of Docker image
registry	string	Docker registry for image
private	bool	Indicates private image (require login)
config	string	Docker secret (default jarvice-docker)
arch	json object	Pointer for multi-arch support

Arch Object

Key	Value	Description
amd64	string	amd64 Docker image to pull from registry
ppc64le	string	ppc64le Docker image to pull from registry

Example

[
    {
        "ref": "ubuntu:xenial",
        "registry": "docker.io",
        "private": false,
        "config": "jarvice-docker",
        "arch": {
            "amd64": "docker.io/library/ubuntu:xenial",
            "ppc64le": "docker.io/ppc64le/ubuntu:xenial"
        }
    },
    {
        "ref": "fail-test",
        "registry": "docker.io",
        "private": true,
        "config": "jarvice-docker",
        "arch": {
            "amd64": "docker.io/kenhill/abc123:test"
        }
    }
]

Literal

interval := delay in seconds between cache update

Create K8s Daemon Set

1. Create image json file at config/image.config
2. Create image-cache Config Map

kubectl --namespace=<namespace> create configmap image-cache --from-file config/ --from-literal interval=300

3. Create Daemon Set

kubectl --namespace=<namespace> create -f jarvice-cache-pull.yaml

Update Image Cache

1. Update config/image.config
2. Replace Config Map

kubectl --namespace=<namespace> create configmap image-cache --from-file config/ --from-literal interval=300 -o yaml --dry-run | kubectl replace -f -

Add Docker Registry User

1. Create new kubernetes.io/dockerconfigjson secret in appropriate namespace
2. Update jarvice-cache-pull.yaml to include new secret

        volumeMounts:
...
        - name: jarvice-docker 
          mountPath: /root/.docker/jarvice-docker/config.json
          subPath: config.json
        - name: <new-secret>
          mountPath: /root/.docker/<new-config>/config.json
          subPath: config.json
      volumes:
...
      - name: jarvice-docker
        secret:
          secretName: jarvice-docker
          items:
          - key: ".dockerconfigjson"
            path: config.json
      - name: <new-secret> 
        secret:
          secretName: <k8s-secret>
          items:
          - key: ".dockerconfigjson"
            path: config.json

Note <new-config> must match the config key in config/image.json

Authors

• Kenneth Hill - Initial work - ken.hill@nimbix.net

License

This project uses an Open Source license - see the LICENSE.md file for details