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Uploading container images to your openshift registry

I recently started exploring OpenShift, and while I did find the concept of builds and imagestreams to be quite useful. I didn’t find a straight forward way to upload a docker image from my machine towards the cluster’s image registry.

So, for reference, I gathered this script from the CI scripts of the openshift logging project.

#!/bin/bash

# Define constants
registry_namespace=openshift-image-registry
registry_svc=image-registry
LOCAL_PORT=5000

# Get port where the remote registry is on
registry_port=$(oc get svc $registry_svc -n $registry_namespace -o jsonpath='{.spec.ports[0].port}')

# Get object that we'll port forward to
port_fwd_obj=$(oc get pods -n $registry_namespace | awk '/^image-registry-/ {print $1}' )

# Do port forwarding on the needed pod
oc --loglevel=9 port-forward "$port_fwd_obj" -n "$registry_namespace" "$LOCAL_PORT:$registry_port" > pf.log 2>&1 &

port_foward_proc=$!
echo "The process spawned is $port_foward_proc"

# Get token for kubeadmin user
oc login -u kubeadmin -p "$(cat ~/openshift-dev-cluster/auth/kubeadmin-password)"

# Use token to log in with docker
docker login -u "kubeadmin" -p "$(oc whoami -t)" localhost:5000

This allows you to use localhost:5000 as an endpoint to upload your images towards your clusters image registry. Note that you’ll need to specify the specific openshift “project” as part of the path when you’re uploading images.

Lets say, for instance, that you want to upload the image my-image, and you have access to the project default. You’ll do:

docker push localhost:5000/default/my-image:latest

Note when you want to use your new image in an application, you must replace localhost:5000 with image-registry.openshift-image-registry.svc:5000, since that’s the URL that OpenShift makes available.

So, you’ll have something as:

...
    spec:
      containers:
        ...
        image: image-registry.openshift-image-registry.svc:5000/default/my-image:latest
        imagePullPolicy: Always

Note that I also tried to create a route towards the openshift-image-registry service. However, that didn’t work for me, as the registry wasn’t getting my requests.

Special thanks to Rich Megginson for guiding my through the CI scripts.

tags: openshift

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