# MultipleInstructionsDisallowed


## Output

```text
Multiple CMD instructions should not be used in the same stage because only the last one will be used
```

## Description

If you have multiple `CMD`, `HEALTHCHECK`, or `ENTRYPOINT` instructions in your
Dockerfile, only the last occurrence is used. An image can only ever have one
`CMD`, `HEALTHCHECK`, and `ENTRYPOINT`.

## Examples

❌ Bad: Duplicate instructions.

```dockerfile
FROM alpine
ENTRYPOINT ["echo", "Hello, Norway!"]
ENTRYPOINT ["echo", "Hello, Sweden!"]
# Only "Hello, Sweden!" will be printed
```

✅ Good: only one `ENTRYPOINT` instruction.

```dockerfile
FROM alpine
ENTRYPOINT ["echo", "Hello, Norway!\nHello, Sweden!"]
```

You can have both a regular, top-level `CMD`
and a separate `CMD` for a `HEALTHCHECK` instruction.

✅ Good: only one top-level `CMD` instruction.

```dockerfile
FROM python:alpine
RUN apk add curl
HEALTHCHECK --interval=1s --timeout=3s \
  CMD ["curl", "-f", "http://localhost:8080"]
CMD ["python", "-m", "http.server", "8080"]
```