Kubectl Cheetsheat

Pods

• kubectl get pods
• kubectl describe pod
• Command Line in Pod – kubectl exec –stdin –tty – /bin/bash
• kubectl logs
• Logs from previous instance of pod – kubectl logs -p

Apply Yaml files

• kubectl apply -f
• kubectl apply -f (runs all yamls in the folder)

Diagnose failed start for container:

If your pod and deployment are failing to start and they do not record any logs when using “logs -p” then you can add a terminationMessagePath to your Deployment spec which will help trap the last error that occurs and log it for you.

Add the terminationMessagePath to your Deployment spec as follows:

spec:
    replicas: 1
    selector:
        matchLabels:
            app: ghost-blog
    template:
        metadata:
            labels:
                app: ghost-blog
        spec:
            containers:
            - name: ghost-blog
              image: ghost:4
              terminationMessagePath: "/tmp/my-log" #ADD THIS LINE

Now run kubectl apply again

kubectl apply -f [filename]

It will fail again however this time you can go to your pods and describe the pod and get an error message included that will hopefully shed light on your problem.