Using oc to manage OpenShift
The Basics
Examples of the basic need to know oc commands to deploy and manage containers on OpenShift.
Pod Documentation
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
Working with pod files
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-snc.okd.manor.one