I have been using init-containers since they became available and find them super useful. My core image (below as web-dev) does not change much, but my init-container image (below as web-data-dev) does change often.
The init-container uses a container image with a version number. I change this version number to the latest value, and then do kubectl apply -f deployment.yaml
For instance, i change eu.gcr.io/project/web-data-dev:187 to eu.gcr.io/project/web-data-dev:188 before running kubectl apply.
When I do this however, no deployment happens, if i make any changes to the image the init-container uses, the deployment will still not happen. I assume this is because the init-container changes are not being detected.
I then tried to just put some garbage in the image field, like this: "image": "thisIsNotAnImage" and run kubectl apply -f again, but the update is still not applied.
My question is - How do i make kubectl apply -f detect an image tag change in an init-container? am i doing something wrong, is this a bug, or is this simply not implemented yet because init-containers are Alpha?
The full deployment YAML is below.
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: web-deployment
spec:
replicas: 1
strategy:
rollingUpdate:
maxUnavailable: 0
template:
metadata:
labels:
app: web
tier: frontend
annotations:
pod.alpha.kubernetes.io/init-containers: '[
{
"name": "initialiser1",
"image": "eu.gcr.io/project/web-data-dev:187",
"command": ["cp", "-r", "/data-in/", "/opt/"],
"volumeMounts": [
{
"name": "file-share",
"mountPath": "/opt/"
}
]
}
]'
spec:
containers:
- image: eu.gcr.io/project/web-dev:20
name: web
resources:
requests:
cpu: 10m
memory: 40Mi
ports:
- containerPort: 80
name: http
- containerPort: 443
name: https
volumeMounts:
- name: file-share
mountPath: /opt/
volumes:
- name: file-share
emptyDir: {}If you are using Kubernetes 1.4, try to change pod.alpha.kubernetes.io/init-containers to pod.beta.kubernetes.io/init-containers.
I can't find a proper issue on GitHub, but behaviour of these two annotations is different. I can do kubectl apply -f with the second one and the deployment will be updated.
You can test it using the example below:
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
name: nginx
spec:
template:
metadata:
labels:
app: nginx
annotations:
pod.beta.kubernetes.io/init-containers: '[
{
"name": "install",
"image": "busybox",
"command": ["/bin/sh", "-c", "echo foo > /work-dir/index.html"],
"volumeMounts": [
{
"name": "workdir",
"mountPath": "/work-dir"
}
]
}
]'
spec:
volumes:
- name: workdir
emptyDir: {}
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
volumeMounts:
- name: workdir
mountPath: /usr/share/nginx/htmlTry to change foo to bar and see the result:
$ cat nginx.yaml | kubectl apply -f -
deployment "nginx" created
$ curl $(minikube service nginx --url)
Waiting, endpoint for service is not ready yet...
foo
$ cat nginx.yaml | sed -e 's/foo/bar/g' | kubectl apply -f -
deployment "nginx" configured
$ curl $(minikube service nginx --url)
Waiting, endpoint for service is not ready yet...
bar
The same thing using pod.alpha.kubernetes.io/init-containers:
$ curl $(minikube service nginx --url)
Waiting, endpoint for service is not ready yet...
foo
$ cat nginx.yaml | sed -e 's/foo/bar/g' | kubectl apply -f -
deployment "nginx" configured
$ curl $(minikube service nginx --url)
foo