Docker

Error: driver failed: port is already allocated

Docker Port Already Allocated

The host port you're mapping to is already in use.

Common Causes

Another container using the port
Host process on that port
Previous container not fully stopped

Fixes

1. Use different host port
```
docker run -p 3001:3000 myimage
```
2. Stop conflicting container
```
docker ps
docker stop <container_id>
```

3. Let Docker assign port

docker run -p 3000 myimage  # use docker port to see mapping

Still not fixed?

• Search the exact error message on Stack Overflow or GitHub Issues
• Check the official docs for the language or tool
• Ensure your versions (Node, Python, npm, Docker) are up to date
• Try in a minimal reproduction (new project, single file)

Related Errors

Address Already in Use No Space Left on Device

DuskTools That Might Help

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All Errors

JavaScript Heap Out of Memory ModuleNotFoundError Address Already in Use IndentationError Cannot Find Module Peer Dependency Warning CORS Policy Blocked TypeError: 'NoneType' Not Subscriptable Merge Conflict ENOENT: No Such File or Directory KeyError MaxListenersExceededWarning RecursionError Detached HEAD State EACCES: Permission Denied ValueError No Space Left on Device ERR_REQUIRE_ESM FileNotFoundError