docker-git-bash-guide

# Docker on Windows Git Bash / MINGW - Path Conversion Guide

This skill provides comprehensive guidance on handling Docker commands in Git Bash (MINGW) on Windows, with specific focus on volume mount path conversion issues and solutions.

## The Path Conversion Problem

When running Docker commands in Git Bash (MINGW) or MSYS2 on Windows, automatic path conversion can cause serious issues with volume mounts and other Docker commands.

### What Triggers Automatic Conversion

MSYS/MINGW shells automatically convert arguments that look like Unix paths when calling Windows executables (like `docker.exe`):

**Examples of problematic conversions:**
```bash
# What you type:
docker run -v /c/Users/project:/app myimage

# What Docker receives (BROKEN):
docker run -v C:\Program Files\Git\c\Users\project:/app myimage
```

**Triggers for path conversion:**
- Leading forward slash (`/`) in arguments
- Colon-separated path lists (`/foo:/bar`)
- Arguments with path components after `-` or `,`

**What's exempt from conversion:**
- Arguments containing `=` (variable assignments)
- Drive letters (`C:`)
- Arguments with `;` (already Windows format)
- Arguments starting with `//` (network paths/Windows switches)

## Shell Detection for Docker Commands

### Detecting Git Bash / MINGW Environment

Use these environment variables to detect when path conversion issues may occur:

```bash
# Most reliable: Check for MSYSTEM
if [ -n "$MSYSTEM" ]; then
  echo "Running in Git Bash/MINGW - path conversion needed"
fi

# Alternative: Check uname
if [[ "$(uname -s)" == MINGW* ]]; then
  echo "Running in MINGW environment"
fi

# Environment variable to check:
# MSYSTEM values: MINGW64, MINGW32, MSYS
```

## Solution 1: MSYS_NO_PATHCONV (Recommended for Git Bash)

The most reliable solution for Git Bash on Windows.

### Per-Command Usage

Prefix each Docker command with `MSYS_NO_PATHCONV=1`:

```bash
# Volume mount with $(pwd)
MSYS_NO_PATHCONV=1 docker run -v $(pwd):/app myimage

# Volume mount with