Skip to main content

Using oc to manage OpenShift

The Basics

Examples of the basic need to know oc commands to deploy and manage containers on OpenShift.

Pods

Using oc explain it is simple to get the ducumentation for the running version of OpenShift. Here are a few basics.

Get built-in documentation for Pods

oc explain pod

Get the pod spec

oc explain pod.spec

Details on the pod's containers

oc explain pod.spec.containers

Details about the pod's containers images

oc explain pod.spec.containers.image

Example of a pod file

apiVersion: v1
kind: Pod
metadata:
  name: hello-world-pod
  labels:
    app: hello-world-pod
spec:
  containers:
  - env:
    - name: MESSAGE
      value: Hi there! You've run a pod.
    image: docker.io/mcleary/helloworld-go
    imagePullPolicy: Always
    name: hello-world-override
    resources: {}

Create a Pod on OpenShift based on a file

oc create -f pod.yaml

Use oc get to information from OpenShift

Get pods

oc get pods

Watch pods deploy

oc get pods --watch

Get all resources

oc get all

Access the shell of a running container. Use oc get pods to get the pod name.

oc rsh <pod-name>

Use port forwards to interact with the pod on the local machine. Get the pod name from the oc get pods.

oc port-forward <pod-name> <local_port>:pod_port>

Delete OpenShift resources use the following syntax

oc delete <resource type> <resource name>

Delete a pod

oc delete pod <pod-name>

Deployments

Deploy an existing image based on its tag

oc new-app mcleary/helloworld-go:latest --as-deployment-config

Deploy an application from Git

oc new-app https://github.com/clusterapps/helloworld-go.git --as-deployment-config

Follow build progress when using

oc logs -f bc/helloworld-go

Set the name for the DeploymentConfig

oc new-app mcleary/helloworld-go --name hello-app --as-deployment-config

DeploymentConfig with a parameter

oc new-app MESSAGE="This is a parameter" mcleary/helloworld-go --name hello-app --as-deployment-config

DeploymentConfig with many patameters

oc new-app mysql MYSQL_USER=user MYSQL_PASSWORD=pass MYSQL_DATABASE=testdb -l db=mysql

Get information about a DeploymentConfig

Describe the DC to get its labels

oc describe dc/hello-app

Get the full YAML definition

oc get -o yaml dc/hello-app

Roll out the latest version of the application

oc rollout latest dc/hello-app

Roll back to the previous version of the application

oc rollback dc/hello-app

Delete a single resource

oc delete <resource> <name>
oc delete dc hello-app # Delete deployment config
oc delete svc hello-app # Delete a service

Delete all application resources using labels (get labels from oc describe)

oc delete all -l app=app=hello-app

Delete everything in a project

oc delete all --all

Networking

Get service documentation

Access oc explain documentation oc explain service

Get information about Service spec

oc explain service.spec

Get YAML definition for a service

oc get -o yaml service/hello-world

Get YAML definition for a route

oc get -o yaml route/hello-world

Creating services

Create a service for a single pod

oc expose --port 8080 pod/hello-world-pod

Create a service for a DeploymentConfig

oc expose --port 8080 dc/hello-world

Check that the service and pod are connected properly

oc status

Using Pod environment variables to find service Virtual IPs

Log into a pod. Get pod name from oc get pods

oc rsh pod/helloworld-2

Inside the pod, get all environment variables

env

Testing connectivity using environment variables with wget

wget -qO- $HELLOWORLD_GO_PORT_8080_TCP_ADDR:$HELLOWORLD_GO_PORT_8080_TCP_PORT

Creating Routes

Create a Route based on a Service. Get the service name from oc get svc

oc expose svc/helloworld-go

Get the Route URL

oc status

Check the route

curl helloworld-go-lab1.apps.okd4.example.com

ConfigMaps

Create a ConfigMap using literal command line arguments

oc create configmap helloconfig --from-literal KEY="VALUE"

Create from a file

oc create configmap helloconfig --from-file=MESSAGE.txt

Create from a file with a key override

oc create configmap helloconfig --from-file=MESSAGE=MESSAGE.txt

Create using --from-file with a directory

oc create configmap helloconfig --from-file pods

Verify

oc get -o yaml configmap/helloconfig

Consuming ConfigMaps as Environment Variables

Set environment variables

oc set env dc/hello-app --from cm/helloconfig

Secrets

A simple generic (Opaque) Secret

oc create secret generic <secret-name> --from-literal KEY="VALUE"

Check the Secret

oc get -o yaml secret/<secret-name>

Consume the Secret as Environment Variables the same as ConfigMaps

oc set env dc/<dc-name> --from secret/<secret-name>
Back to top