DB / Docker / 1
CRITICAL

Docker Non-zero Exit Status / Command Failed

Docker Exit Code 1 indicates that the container's main process (the command or entrypoint) exited with a non-zero status. This is a generic error code signifying a failure or an error during the execution of the primary application or script within the container.

Common Causes

  • Incorrect command or arguments specified in CMD or ENTRYPOINT.
  • Missing dependencies or files required by the application inside the container.
  • Application logic error causing the process to terminate abnormally.
  • Permissions issues preventing the application from accessing resources.
  • Configuration errors within the application.
  • Container trying to run a non-existent executable or script.

How to Fix

1 Check Container Logs

The first and most crucial step is to examine the container's logs. Docker logs often contain specific error messages from the application running inside the container, which can pinpoint the exact cause of the exit.

BASH
$ docker logs <container_id_or_name>

2 Verify CMD and ENTRYPOINT

Ensure that the CMD and ENTRYPOINT instructions in your Dockerfile (or the command specified with 'docker run') are correct, refer to existing executables, and have the right arguments. A typo or incorrect path can cause immediate failure.

BASH
$ docker inspect <image_name_or_id> | grep -E 'Cmd|Entrypoint'

3 Debug Interactively

Run the container in interactive mode with a shell (e.g., 'bash' or 'sh') to manually execute commands, check file paths, permissions, and environment variables, simulating the container's environment to identify the failure point.

BASH
$ docker run -it --entrypoint /bin/bash <image_name_or_id>

4 Validate Dependencies and Configuration

Ensure all necessary application dependencies are installed and accessible within the container. Verify configuration files are correctly placed and formatted, and that environment variables are set as expected by the application.

BASH
$ docker run -it --entrypoint /bin/bash <image_name_or_id> -c 'ls -l /app && cat /app/config.json'

5 Rebuild Docker Image

If you've made changes to your Dockerfile or application code, ensure you rebuild the Docker image to incorporate those changes. Running with a stale image can lead to unexpected behavior and errors.

BASH
$ docker build -t myapp:latest .