配置livenessProbe与readinessProbe时无法创建指定文件，请求协助排查

Hey there, let's work through why your liveness probe is failing because it can't find /tmp/healthy—I've run into similar headaches before, so let's break this down step by step:

1. Confirm the touch Command Is Actually Running #

First, let's make sure the command that creates your marker file is executing successfully:

• Pull your container logs to check for startup script errors:

  kubectl logs <your-pod-name>
  

  If an earlier command in your startup script fails and exits, the touch /tmp/healthy command might never get to run. Look for error messages that halt script execution.
• Manually jump into the container to test the command directly:

  kubectl exec -it <your-pod-name> -- /bin/sh
  # Once inside, run these commands:
  touch /tmp/healthy
  ls /tmp
  

  If this fails, you'll see an explicit error (like permission denied) pointing to the root cause. While /tmp is usually world-writable, some hardened images or Pod securityContext settings might restrict write access for non-root users.

2. Fix Probe Timing Mismatches #

A super common issue is the probe checking too early before your container finishes initializing:

• Look at your probe's initialDelaySeconds value. If it's set to a tiny number (like 0 or 1), the probe starts checking before your touch command has a chance to run. Try bumping this up to give your container time to set up—start with 30 seconds and adjust as needed:

  livenessProbe:
    exec:
      command:
      - cat
      - /tmp/healthy
    initialDelaySeconds: 30
    periodSeconds: 10
  

3. Double-Check Paths for Typos #

It sounds trivial, but typos are easy to miss! Verify:

• The path in your probe (/tmp/healthy) matches exactly what's in your touch command. No mix-ups like /temp/healthy (a common typo between "tmp" and "temp").
• You're using absolute paths for both the touch command and probe check. Relative paths can break if your container's working directory isn't what you expect.

4. Rule Out File Cleanup Processes #

In some setups, cleanup scripts or sidecar containers might be deleting files in /tmp. If your Pod has multiple containers, check if any of them are modifying the /tmp directory. You can also temporarily add a sleep 60 after the touch command to see if the file exists briefly before being deleted.

内容的提问来源于stack exchange，提问作者morla