define-command-in-deployment

This example demonstrates how to define a command within a Kubernetes Deployment. We'll use a simple while loop to continuously echo "hello" every 10 seconds.

YAML Configuration

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: run-command-with-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: debug
  template:
    metadata:
      labels:
        app: debug
    spec:
      containers:
      - name: test
        image: busybox
        command: ["/bin/sh"]
        args: ["-c", "while true; do echo hello; sleep 10;done"]

Explanation

command and args

The command field specifies the command to execute. Here, we use /bin/sh, a shell available in the busybox image. The args field provides arguments to the command. The -c argument tells /bin/sh to execute the following string as a command.

Continuous Loop

The while true; do echo hello; sleep 10; done command creates a loop that continuously echoes "hello" to the standard output and then pauses for 10 seconds.

Further Considerations

For more complex commands or scripts, consider using a more robust base image with additional tools and utilities. You might also want to explore using init containers or sidecars for more advanced scenarios.

Remember to adapt this example to your specific needs and environment.