Fork the repository (https://github.com/peterj/simple-http-page.git
) and use your fork in the YAML below.
apiVersion: v1
kind: Pod
metadata:
name: website
spec:
initContainers:
- name: clone-repo
image: alpine/git
command:
- git
- clone
- --progress
- <https://github.com/peterj/simple-http-page.git>
- /usr/share/nginx/html
volumeMounts:
- name: web
mountPath: "/usr/share/nginx/html"
containers:
- name: nginx
image: nginx
ports:
- name: http
containerPort: 80
volumeMounts:
- name: web
mountPath: "/usr/share/nginx/html"
- name: refresh
image: alpine/git
command:
- sh
- -c
- watch -n 60 git pull
workingDir: /usr/share/nginx/html
volumeMounts:
- name: web
mountPath: "/usr/share/nginx/html"
volumes:
- name: web
emptyDir: {}
Save the above YAML to sidecar-container.yaml
and create the Pod using kubectl apply -f sidecar-container.yaml
.
If you run kubectl get pods
once the init container has executed, you will notice the READY
column now shows 2/2
. These numbers tell you right away that this Pod has a total of two containers, and both of them are ready:
$ kubectl get po
NAME READY STATUS RESTARTS AGE
website 2/2 Running 0 3m39s
If you set up the port forward to the Pod using kubectl port-forward pod/website 8000:80
command and open the browser to http://localhost:8000
, you will see the same webpage as before.
We can open a separate terminal window and watch the logs from the refresh
container inside the website
Pod:
$ kubectl logs website -c refresh -f
Every 60.0s: git pull
Already up to date.
The watch
command is running, and the response from the last git pull
command was Already up to date
.
Let's make a change to the index.html
in the repository you forked - you change some values or add other HTML elements.
Next, you need to stage this and commit it to the master
branch. The easiest way to do that is from the Github's webpage. Open the index.html
on Github (I am opening https://github.com/peterj/simple-http-page/blob/master/index.html
, but you should replace my username peterj
with your username or the organization you forked the repo to) and click the pencil icon to edit the file.
Make the change to the index.html
file and click the Commit changes button to commit them to the branch. Next, watch the output from the refresh
container, and you should see the output like this:
Every 60.0s: git pull
From <https://github.com/peterj/simple-http-page>
f804d4c..ad75286 master -> origin/master
Updating f804d4c..ad75286
Fast-forward
index.html | 1 +
1 file changed, 1 insertion(+)
The above output indicates changes to the repository. Git pulls the updated file to the shared volume.
Start the port forward command:
kubectl port-forward pod/website 8000:80
Finally, refresh your browser where you have http://localhost:8000
opened, and you will notice the changes on the page.
kubectl delete pod website