Executable not running in POD, but runs in Docker container

General Discussions
1

Cluster information:

Kubernetes version: 1.27.2
Cloud being used: docker-desktop’s kubernetes and AKS (Azure)
Installation method:
Host OS: Mac Os Sonoma 14

Hello, I built a docker image containing an executable linux file (named app). When I launch the container with docker run the executable spins up and everything works fine.

If I pull that same image to my kubernetes cluster (both docker-desktop’s and azure’s) nothing happens and the created POD starts a crashbackoff loop. I put a wait command in the deployment yaml and entered the pod with sh, running sh -x ./app returns
/app: 1: Syntax error: ")" unexpected

How can the same executable run in a container, but not in a POD?

This is driving me crazy, any idea? Thanks

2

Post your Pod/Deployment/Job YAML.

3 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: registration-native
spec:
  replicas: 1
  selector:
    matchLabels:
      component: registration-native
  template:
    metadata:
      labels:
        component: registration-native
    spec:
      containers:
        - name: registration-native
          image: local/repo:registration-native
          imagePullPolicy: "Never"
          ports:
            - containerPort: 8080

It’s the simplest possible. The image is taken directly from my local environment, but i also tried to pull it from my repo at docker hub.

4

Are you setting ther pod.spec.container command or args ?

running sh -x ./app returns
/app: 1: Syntax error: ")" unexpected

Is the app a shell script?

It looks like the shell in your container doesn’t parse it.

5

It is a native java native image, a linux executable. What is not clear to me is how it works in docker but not in the pod. Does kubernetes interpreter is somehow different?

6

It could be that the VM doesn’t have the right binfmt modules loaded to run Java directly. Usually one would run it as java <file>, right? It’s been a while since I Java’ed.

sh -x means “run this as a shell script” which is not what you want.

7

I found the library that was causing the issue, spring cloud kubernetes. Still it’s not clear to me why it works in a container but not in a pod. Anyway, issue solved!