dockeropenshiftminishift

Openshift & docker - which registry can I use for Minishift?


It is easy to work with Openshift as a Container As A Service, see the detailed steps. So, via the docker client I can work with Openshift.

I would like to work on my laptop with Minishift. That's the local version of Openshift on your laptop.

Which docker registry should I use in combination with Minishift? Minishift doesn't have it's own registry - I guess.

So, I would like to do:

$ maven clean install -- building the application
$ oc login to your minishift environment
$ docker build -t myproject/mynewapplication:latest
$ docker tag -- ?? normally to a openshift docker registry entry
$ docker push -- ?? to a local docker registry?
$ on 1st time: $ oc new-app mynewapplication
$ on updates: $ oc rollout latest dc/mynewapplication-n myproject

Solution

  • I use just docker and oc cluster up which is very similar. The internal registry that is deployed has an address in the 172.30.0.0/16 space (ie. the default service network).

    $ oc login -u system:admin
    $ oc get svc -n default  | grep registry
    docker-registry   ClusterIP   172.30.1.1     <none>        5000/TCP                  14m
    

    Now, this service IP is internal to the cluster, but it can be exposed on the router:

    $oc expose svc docker-registry -n default
    $oc get route -n default  | grep registry
    docker-registry   docker-registry-default.127.0.0.1.nip.io             docker-registry   5000-tcp                 None
    

    In my example, the route was docker-registry-default.127.0.0.1.nip.io

    With this route, you can log in with your developer account and your token

    $oc login -u developer
    $docker login docker-registry-default.127.0.0.1.nip.io -p $(oc whoami -t) -u developer
    Login Succeeded
    

    Note: oc cluster up is ephemeral by default; the docs can provide instructions on how to make this setup persistent.

    One additional note is that if you want OpenShift to try to use some of it's native builders, you can simply run oc new-app . --name <appname> from within the your source code directory.

    $ cat Dockerfile 
    FROM centos:latest
    
    $ oc new-app . --name=app1
    --> Found Docker image 49f7960 (5 days old) from Docker Hub for "centos:latest"
    
        * An image stream will be created as "centos:latest" that will track the source image
        * A Docker build using binary input will be created
          * The resulting image will be pushed to image stream "app1:latest"
          * A binary build was created, use 'start-build --from-dir' to trigger a new build
        * This image will be deployed in deployment config "app1"
        * The image does not expose any ports - if you want to load balance or send traffic to this component
          you will need to create a service with 'expose dc/app1 --port=[port]' later
        * WARNING: Image "centos:latest" runs as the 'root' user which may not be permitted by your cluster administrator
    
    --> Creating resources ...
        imagestream "centos" created
        imagestream "app1" created
        buildconfig "app1" created
        deploymentconfig "app1" created
    --> Success
        Build scheduled, use 'oc logs -f bc/app1' to track its progress.
        Run 'oc status' to view your app.