I have in my application a shell that I need to execute once the container is started and that it remains in the background, I have seen using lifecycle but it does not work for me

 ports:
    - name: php-port
      containerPort: 9000
    lifecycle:
        postStart:
          exec:
            command: ["/bin/sh", "sh /root/script.sh"]

I need an artisan execution to stay in the background once the container is started

CodePudding user response：

You can try using something like supervisor

http://supervisord.org/

We use that to start the main process and a monitoring agent in the background so we get metrics out of it. supervisor would also ensure those processes stay up if they crash or terminate.

CodePudding user response：

When the lifecycle hooks (e.g. postStart) do not work for you, you could add another container to your pod, which runs parallel to your main container (sidecar pattern):

apiVersion: v1
kind: Pod
metadata:
  name: foo
spec:
  containers:
  - name: main
    image: some/image
    ...
  - name: sidecar
    image: another/container

If your 2nd container should only start after your main container started successfully, you need some kind of notification. This could be for example that the main container creates a file on a shared volume (e.g. an empty dir) for which the 2nd container waits until it starts it's main process. The docs have an example about a shared volume for two containers in the same pod. This obviously requires to add some additional logic to the main container.

apiVersion: v1
kind: Pod
metadata:
  name: foo
spec:
  volumes:
  - name: shared-data
    emptyDir: {}
  containers:
  - name: main
    image: some/image
    volumeMounts:
    - name: shared-data
      mountPath: /some/path
  - name: sidecar
    image: another/image
    volumeMounts:
    - name: shared-data
      mountPath: /trigger
    command: ["/bin/bash"]
    args: ["-c", "while [ ! -f /trigger/triggerfile ]; do sleep 1; done; ./your/2nd-app"]