Kestra: every script execution fails with Docker runner (script file not accessible)

# Kestra: every script execution fails with Docker runner (script file not accessible)

## What's going on

Every script task using the Docker runner in Kestra failed: the script file (e.g. main.py from inputFiles) wasnt accessible inside the runner container. It happened on Windows with WSL2, on Docker Desktop, and on a Linux Docker Swarm setup, so it wasnt Windows-specific. The Kestra team reproduced it: the Docker runner couldnt create the input files in the temp working directory because the tmp path wasnt aligned between Kestra and the runner container.

## The verified fix

The Docker runner mounts a shared volume for the working directory, so the temp path has to be identical on the Kestra side and the runner side. If you customize it, mount the same host directory into the Kestra container at the same path and tell Kestra to use it:

```yaml
services:
  app:
    volumes:
      - /mnt/storage-pool/appdata/kestra/tmp/kestra-wd:/mnt/storage-pool/appdata/kestra/tmp/kestra-wd
      - /var/run/docker.sock:/var/run/docker.sock
    environment:
      KESTRA_CONFIGURATION: |
        kestra:
          tasks:
            tmp-dir:
              path: /mnt/storage-pool/appdata/kestra/tmp/kestra-wd/tmp
```

Two reporters confirmed this config fixed it ("This works on ubuntu/swarm", "with tmp path like in your example it works"). Create the host directories beforehand with `mkdir -p`, or youll get a bind mount error instead.

Source: https://github.com/kestra-io/kestra/issues/3590

## How to use this

Take the question above and check if it matches what you're seeing. If it does, work through the verified fix step by step. Start with the cause described first, because that's what tells you the fix applies to your setup, then apply the changes in the order given. Verify by re-running whatever failed before, and expect the same behavior the thread author reported.