Usage of OpenShift ConfigMaps in DeploymentConfigurations

Question

On the OpenShift Documentation for ConfigMaps (https://docs.openshift.com/enterprise/3.2/dev_guide/configmaps.html) is only an example of usage within Pods. But can I use ConfigMaps also inside DeploymentConfig?

The parameter declarations inside Pods look symilar to the DeploymentConfig.

apiVersion: v1
kind: Pod
metadata:
  name: dapi-test-pod
spec:
  containers:
    - name: test-container
      image: gcr.io/google_containers/busybox
      command: [ "/bin/sh", "-c", "env" ]
      env:
        - name: SPECIAL_LEVEL_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config
              key: special.how
        - name: SPECIAL_TYPE_KEY
          valueFrom:
            configMapKeyRef:
              name: special-config
              key: special.type
  restartPolicy: Never

Both use the env property.

"spec": {
                        "containers": [
                            {
                                "env": [
                                    {
                                        "name": "PORT",
                                        "value": "${MF-PORT}"
                                    },
                                    {
                                        "name": "NODE_ENV",
                                        "value": "${MF-ENVIRONMENT}"
                                    }
                                ],

score 6 · Accepted Answer · answered Apr 17 '18 at 06:06

Yes, you can use ConfigMap from a DeploymentConfig.

If you already have a deployed application, you can add environment variables with them being set from a config map using the command:

oc set env dc/blog --from configmap/blog-settings

You can see how that translates into changes in the deployment config by instead running:

oc set env dc/blog --from configmap/blog-settings --dry-run -o json

For example, if the config map was originally created using:

oc create configmap blog-settings \
      --from-literal BLOG_BANNER_COLOR=blue \
      --from-literal BLOG_SITE_NAME="My Blog"

that would result in changes in the deployment config of:

                "env": [
                    {
                        "name": "BLOG_BANNER_COLOR",
                        "valueFrom": {
                            "configMapKeyRef": {
                                "name": "blog-settings",
                                "key": "BLOG_BANNER_COLOR"
                            }
                        }
                    },
                    {
                        "name": "BLOG_SITE_NAME",
                        "valueFrom": {
                            "configMapKeyRef": {
                                "name": "blog-settings",
                                "key": "BLOG_SITE_NAME"
                            }
                        }
                    }
                ],

You can find a details on using config maps, and secrets, in the free eBook on OpenShift at:

https://www.openshift.com/promotions/deploying-to-openshift.html

Usage of OpenShift ConfigMaps in DeploymentConfigurations

1 Answers1