Is this a BUG REPORT or FEATURE REQUEST?:

/kind bug

What happened:

I created a cronjob with an init container. This works correctly. I then updated that cronjob (with kubectl apply) to no longer have an init container. This doesn't work -- after updating the cronjob, the init container is still there. (also, there are no error messages)

Strangely, updating the init container works correctly, but removing the init container does not work.

(I'm planning to work on fixing this, but wanted to report an issue first in case anyone has any thoughts)

What you expected to happen:

I expected the init container to be removed.

How to reproduce it (as minimally and precisely as possible):

I created a gist with a script that reproduces this issue at https://gist.github.com/julia-stripe/8b9ad694c9f0208828493f012582c863. Here's how to run the script:

minikube start
git clone https://gist.github.com/8b9ad694c9f0208828493f012582c863.git cronjob-init-containers
cd cronjob-init-containers
bash run.sh

Here's the relevant output:

======= CREATE cronjob with init container
cronjob "minikube-test-job" created
list of init containers: (correct)
[
  {
    "command": [
      "/bin/sh",
      "-c",
      "ls"
    ],
    "image": "gcr.io/google_containers/debian-iptables-amd64:v5",
    "imagePullPolicy": "IfNotPresent",
    "name": "init-myservice",
    "resources": {},
    "terminationMessagePath": "/dev/termination-log",
    "terminationMessagePolicy": "File"
  }
]
======= APPLY cronjob with no init container
cronjob "minikube-test-job" configured
list of init containers: (incorrect, should be empty)
[
  {
    "command": [
      "/bin/sh",
      "-c",
      "ls"
    ],
    "image": "gcr.io/google_containers/debian-iptables-amd64:v5",
    "imagePullPolicy": "IfNotPresent",
    "name": "init-myservice",
    "resources": {},
    "terminationMessagePath": "/dev/termination-log",
    "terminationMessagePolicy": "File"
  }
]

Anything else we need to know?:

a few more notes:

• modifying the init containers on a cron job also doesn't work
• modifying the init containers on a cron job does work if you use the legacy pod.beta.kubernetes.io/init-containers annotations, but deleting them still doesn't

I noticed that modifying or deleting the init container on a Job also doesn't work (see this output) for what happens.

I'd expect modifying/deleting the init containers on a Job object to give a validation error, but instead it just silently fails. Overall everything related to changing init containers on jobs / cronjobs seems to not work well.

Environment:

• Kubernetes version: 1.7.0