Skip to content
This repository has been archived by the owner on Aug 5, 2020. It is now read-only.

Latest commit

 

History

History
103 lines (79 loc) · 3.18 KB

k8s-operations-with-kubectl.md

File metadata and controls

103 lines (79 loc) · 3.18 KB
Raw

Kubernetes App Operations

Scale the number of Pods:

Check the # of wildfly pod by running kubectl get po:

kubectl get po

(SAMPLE OUTPUT)
NAME                         READY     STATUS    RESTARTS   AGE
modcluster-500718032-kfb17   1/1       Running   0          2h
omsagent-gj322               1/1       Running   0          16m
omsagent-hsc5r               1/1       Running   0          51m
wildfly-1364584080-2qswl     1/1       Running   0          1h

Or you can check by running kubectl get deploy:

kubectl get deploy wildfly

(SAMPLE OUTPUT)
NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
wildfly   1         1         1            1           1h

So you have 1 pod for wildfly. Then, if you want to scale the # of pods to 3, run the following command:

kubectl scale --replicas=3 deploy wildfly

Check the # of wildfly pod again:

kubectl get deploy wildfly

(SAMPLE OUTPUT)
NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
wildfly   3         3         3            3           1h

Update the kubernete app:

First of all, prepare a new container image for the app and push it to a container registry.

Option1: Update the app by running "kubectl set image":

Suppose you upgrade the container image for the app from tag version 1.0 to 1.1, run the following command:

kubectl set image deploy wildfly wildfly=<acrLoginServer>/yoichikawasaki/wildfly-ticketmonster-ha:1.1 --record

Option2: Update the app by running "kubectl apply":

Suppose you upgrade the container image for the app from tag version 1.0 to 1.1, Replace the container image part of kubernetes/wildfly-server.yaml file with the container name:tag:

containers:
- name: wildfly
    image: yoichikawasaki/wildfly-ticketmonster-ha:1.1

Then, run the following command to update the app in your kubernete cluster:

kubectl apply -f <repodir>/kubernetes/wildfly-server.yaml --record

You can check if it's actually updated in the cluster by running kubectl describe like this:

kubectl describe deploy wildfly

(SAMPLE OUTPUT)
...
   wildfly:
    Image:  yoichikawasaki/wildfly-ticketmonster-ha:1.1
...

Get a shell to the running Container

Get a list of Pods by running kubectrl get po:

kubectrl get po

(SAMPLE OUTPUT)
NAME                         READY     STATUS    RESTARTS   AGE
modcluster-500718032-0d7sv   1/1       Running   0          10h
omsagent-qgsgq               1/1       Running   0          10h
wildfly-1364584080-01z1x     1/1       Running   0          10h
wildfly-1364584080-bb2jt     1/1       Running   0          10h
wildfly-1364584080-hzqq0     1/1       Running   0          10h

Suppose you want to get a shell to the running Container in a Pod named wildfly-1364584080-01z1x (a Pod that has one Container), run the following command:

kubectl exec -it wildfly-1364584080-01z1x -- /bin/bash

See also Get a Shell to a Running Container to lean more about the command.

Cleanup all k8s objects selected by labels

Cleanup all objects that has a label "context=AKSDemo"

kubectl delete svc,deploy,ds -l context=AKSDemo