Kubernetes - How to make simple Linux container Image without App Running permanently

Question

I need to make my Linux container running (without any app or service in it) so I can enter /bin/bash and modify some local linux files before I actually manually run my app from the container shell (this is purely for some debugging purposes so I do not want any modifications in my image itself, please do not suggest that as an option)

I have defined my Kubernetes YAML file hoping that I would be able to execute simple command: ["/bin/bash"] but this does not work because it will execute command and Exit the container. So how I can make it not to exit so I am able to exec container?

apiVersion: apps/v1
kind: Deployment
metadata:
  name: frontarena-ads-deployment2
  labels:
    app: frontarena-ads-deployment2
spec:
  replicas: 1
  template:
    metadata:
      name: frontarena-ads-aks-test2
      labels:
        app: frontarena-ads-aks-test2
    spec:
      nodeSelector:
        "beta.kubernetes.io/os": linux
      restartPolicy: Always
      containers:
      - name: frontarena-ads-aks-test2
        image: test.dev/ads:test2
        imagePullPolicy: Always
        env:
        - name: DB_TYPE
          value: "odbc"
        - name: LANG
          value: "en_US.utf8"
        command: ["/bin/bash"]
      imagePullSecrets:
        - name: fa-repo-secret
  selector:
    matchLabels:
      app: frontarena-ads-aks-test2 

When I want to see what is going on after the deployment I can notice:

NAME                                                      READY   STATUS             RESTARTS   AGE
frontarena-ads-deployment2-546fc4b75-zmmrs                0/1     CrashLoopBackOff   19         77m

kubectl logs $POD doesn't return anything and kubectl describe pod $POD output is:

Command:
  /bin/bash
State:          Waiting
  Reason:       CrashLoopBackOff
Last State:     Terminated
  Reason:       Completed
  Exit Code:    0
  Started:      Wed, 07 Apr 2021 11:40:31 +0000
  Finished:     Wed, 07 Apr 2021 11:40:31 +0000

Answer 1

You just need to run some long/endless process for the container to be up. For example you can read a stream, that'll last forever unless you kill the pod/container:

command: ["/bin/bash", "-c"]
args: ["cat /dev/stdout"]