Why Do My Docker Containers Exit? Understanding Common Exit Codes

Why does a container stop running? Understanding Docker exit codes helps diagnose container failures. This article lists the most common exit codes and explains the actions that cause them.

How to view exit codes

Method 1: Inspect the pod’s container exit code $ kubectl describe pod xxx Method 2: Use Docker

$ docker ps --filter "status=exited"
$ docker inspect <container-id> --format '{{.State.ExitCode}}'

Method 3: Manual output

$ docker container run alpine sh -c "exit 1"
$ docker container ls -a
CONTAINER ID   IMAGE   COMMAND               CREATED               STATUS
61c688005b3a   alpine  "sh -c 'exit 1'"   About a minute ago   Exited (1) 3 seconds ago

Common exit codes

Exit Code 0

The container has no foreground process attached.

This code is an exception to other exit codes.

It does not necessarily indicate an error; it can be used to stop a container after its work is done.

Running docker run hello-world shows “Hello from Docker!” and the container appears with status code 0.

Exit Code 1

Program error or missing file referenced in Dockerfile (e.g., wrong entrypoint).

Errors can be simple like division by zero or complex such as null reference crashes.

Exit Code 137

Container received SIGKILL (kill -9).

Triggered by docker kill from user or daemon.

Often occurs when pod resource limits are low, causing OOMKilled; the state shows "OOMKilled": true and dmesg logs OOM.

Exit Code 139

Container received SIGSEGV (kill -11), indicating an invalid memory reference.

Usually caused by code issues or problems in the base image.

Exit Code 143

Container received SIGTERM (kill -15), typically from docker stop.

Sometimes docker stop leads to Exit Code 137 if the process cannot handle SIGTERM and Docker escalates to SIGKILL after a timeout.

Less common exit codes

126: Permission problem or non‑executable command.

127: Command not found, often due to a typo in a shell script.

1 or 255: Custom exit codes; many programs use exit(1) or exit(-1) which maps to 255.

Exit code ranges

Valid range is 0‑255; 0 means normal exit.

External interruptions produce codes 129‑255.

Program‑initiated abnormal exits are usually 1‑128.

If a negative code is specified, it is converted using 256 – (|code| % 256).

References

http://tldp.org/LDP/abs/html/exitcodes.html

https://imroc.io/posts/kubernetes/analysis-exitcode/

https://medium.com/better-programming/understanding-docker-container-exit-codes-5ee79a1d58f6