opencode-container-exec

OpenCode plugin for WSL devcontainer integration - run commands inside devcontainers from WSL.

Why?

When using VSCode Dev Containers from WSL, you need to reinstall OpenCode in every new container. This plugin lets you run OpenCode from WSL and route commands to the container automatically.

Features

• Auto-detect running devcontainers via devcontainer.local_folder label
• Container selection by number, ID, or name when multiple containers running
• Visual indicator [🐳 container-name] prefix in bash output
• WSL path conversion automatically converts Linux paths to Windows format
• Direct execution use ! prefix for instant execution without LLM
• Security hardened with input validation and command injection prevention
• Container health checks ensures containers are running before command execution
• Dependency checking validates required CLIs are installed

Prerequisites

System Requirements

• Operating System: Windows 10/11 with WSL (Windows Subsystem for Linux)
• WSL Distribution: Ubuntu (default) or other distributions (configurable)
• Docker: Docker Desktop with WSL 2 backend
• Node.js: Version 18.0.0 or higher

Required Software

1. WSL 2: Installation guide
2. Docker Desktop: Download
   • Enable WSL 2 integration in Docker Desktop settings
3. devcontainer CLI: Install globally

   npm install -g @devcontainers/cli

4. jq (required for scripts/toggle.sh)

   sudo apt-get update && sudo apt-get install -y jq

5. OpenCode CLI: Install from opencode.ai

Verification

Verify your setup:

# Check WSL
wsl --list --verbose

# Check Docker
docker --version
docker ps

# Check devcontainer CLI
devcontainer --version

# Check Node.js
node --version

Installation

From npm (recommended)

npm install -g @isupervillain/opencode-container-exec

Add to your ~/.config/opencode/opencode.json or project opencode.json:

{
  "plugin": ["@isupervillain/opencode-container-exec"]
}

Local installation

1. Clone this repository
2. Copy the plugin directory to ~/.config/opencode/plugins/ or .opencode/plugins/
3. Copy scripts/toggle.sh to a location in your PATH

Note: The /container slash command is automatically installed when the plugin loads (global OpenCode config). No manual setup required.

If you don't see /container immediately, restart OpenCode once so the command file can be discovered. If auto-install fails in your environment, you can still manually copy plugin/command/container.md to ~/.config/opencode/commands/container.md.

Plugin runtime entrypoint contract

For OpenCode runtime loading, keep plugin/index.js limited to plugin export(s) only (for this project: ContainerExecPlugin and default export). Move helper/utility exports to plugin/internal.js.

Usage

Direct execution (instant, no LLM)

# Enable container mode (auto-detect)
!path/to/scripts/toggle.sh on

# Disable container mode
!path/to/scripts/toggle.sh off

# Show current status
!path/to/scripts/toggle.sh status

# List all running devcontainers
!path/to/scripts/toggle.sh list

# Select container by number
!path/to/scripts/toggle.sh on 1

# Select container by ID
!path/to/scripts/toggle.sh on fa6c0c798c6c

# Select container by name
!path/to/scripts/toggle.sh on flamboyant_robinson

Via slash command (LLM processed)

/container on
/container off
/container status
/container list
/container on 1

Visual indicator

When container mode is ON, bash commands show:

[🐳 flamboyant_robinson] /home/vscode
[🐳 flamboyant_robinson] Python 3.12.11

When container mode is OFF:

/home/your-user/projects/your-repo
Python 3.12.11

API Reference

Tools

bash

Execute shell commands. Routes to devcontainer when container mode is enabled.

Description:

• When container mode is ON: Execute shell commands in devcontainer [🐳 container-name]
• When container mode is OFF: Execute shell commands locally on WSL

Arguments:

• command (string, required): Shell command to execute
• timeout (number, optional): Timeout in milliseconds

Returns: Command output with container indicator prefix when applicable.

container

Toggle devcontainer mode on/off for running commands inside a container.

Description: Toggle devcontainer mode on/off for running commands inside a container

Arguments:

• action (enum, required): Action to perform
  • on: Enable container mode
  • off: Disable container mode
  • status: Show current status
  • list: List all running devcontainers
• selection (string, optional): Container selection (number, ID, or name)

Returns: Status message and container information.

Shell Script API

The toggle.sh script provides the same functionality via command line:

toggle.sh [action] [container]

Actions:

• on [container]: Enable container mode (auto-detect or specify container)
• off: Disable container mode
• status: Show current state and available containers
• list: List all running devcontainers

Container Selection:

• Number: Select by position in list (e.g., 1)
• Container ID: Select by Docker container ID (e.g., fa6c0c798c6c)
• Container name: Select by Docker container name (e.g., flamboyant_robinson)

How it works

1. The plugin detects running devcontainers by checking the devcontainer.local_folder Docker label
2. It converts WSL paths to Windows format (prefers wslpath -w, falls back to \\wsl.localhost\<distro>\...)
3. When enabled, bash commands are routed through devcontainer exec --container-id
4. State is persisted in ~/.config/opencode/container-mode.json

Configuration

Environment Variables

Variable	Description	Default	Required
WSL_DISTRO_NAME	WSL distribution name	Ubuntu	No
WSL_DISTRO	Alternate WSL distribution variable (fallback)	unset	No
HOME	User home directory	~	No
NODE_ENV	Node environment	production	No

State File

The plugin stores state in ~/.config/opencode/container-mode.json:

{
  "enabled": true,
  "containerId": "fa6c0c798c6c",
  "containerName": "flamboyant_robinson",
  "containerImage": "mcr.microsoft.com/devcontainers/python:2-3.12-bullseye",
  "directory": "/home/your-user/projects/your-repo"
}

Security: State file is created with restrictive permissions (0o600).

Configuration Options

Currently, the plugin uses automatic configuration. Future versions will support:

• Timeout configuration
• Container selection preferences
• Path conversion options
• Security settings

Troubleshooting

Common Issues

1. No devcontainers found

Symptoms: "No running devcontainers found" error

Solutions:

1. Ensure VSCode has opened a directory in a devcontainer
2. Check if container is running: docker ps
3. Verify container has devcontainer.local_folder label:

   docker inspect --format '{{json .Config.Labels}}' <container_id> | grep devcontainer.local_folder

2. Commands not running in container

Symptoms: Commands execute locally instead of in container

Solutions:

1. Check container mode status:

   !path/to/scripts/toggle.sh status

2. Verify container is still running:

   docker ps | grep <container_name>

3. Re-enable container mode:

   !path/to/scripts/toggle.sh on

3. Path conversion issues

Symptoms: Container not found for current directory

Solutions:

1. Check if using correct WSL distribution:

   echo $WSL_DISTRO_NAME

2. Set distribution name if not Ubuntu (dot/hyphen names are supported, e.g. Ubuntu-24.04):

   export WSL_DISTRO_NAME="Ubuntu-24.04"

3. Verify path conversion:

   wslpath -w "$(pwd)"

4. Permission errors

Symptoms: "Permission denied" or state file errors

Solutions:

1. Check state file permissions:

   ls -la ~/.config/opencode/container-mode.json

2. Fix permissions if needed:

   chmod 600 ~/.config/opencode/container-mode.json

3. Check config directory permissions:

   ls -ld ~/.config/opencode
   chmod 700 ~/.config/opencode

5. Docker connection issues

Symptoms: "Cannot connect to Docker daemon" error

Solutions:

1. Ensure Docker Desktop is running
2. Check WSL integration in Docker Desktop settings
3. Verify Docker socket permissions:

   ls -la /var/run/docker.sock

4. Restart Docker Desktop

6. devcontainer CLI not found

Symptoms: "devcontainer: command not found" error

Solutions:

1. Install devcontainer CLI:

   npm install -g @devcontainers/cli

2. Verify installation:

   devcontainer --version

3. Check PATH includes npm global bin:

   echo $PATH | grep "$(npm config get prefix)/bin"

7. Plugin load crash: TypeError related to plugin.auth

Symptoms: OpenCode fails to load the plugin with a TypeError mentioning plugin.auth.

Cause: plugin/index.js exports non-plugin helper symbols, so runtime plugin detection receives unexpected exports.

Resolution:

1. Ensure plugin/index.js exports only plugin function entrypoints.
2. Move helper utilities to plugin/internal.js.
3. Upgrade to a release that includes this entrypoint/internal split.

Debug Mode

Enable debug logging for troubleshooting:

export NODE_ENV=development

This will output security events and debugging information to stderr.

Log Files

The plugin logs security events in development mode. For production issues:

1. Check system logs: journalctl -u docker
2. Check Docker logs: docker logs <container_id>
3. Check OpenCode logs: ~/.config/opencode/logs/

Security

Security Features

• Input validation: All inputs validated against strict patterns
• Command injection prevention: Proper escaping of shell arguments
• Secure file permissions: State files created with 0o600 permissions
• Atomic file operations: Prevents state file corruption
• Container health checks: Verifies containers are running before execution
• Dependency validation: Checks required CLIs are installed
• Security logging: Logs suspicious activities in development mode

Security Best Practices

1. Keep dependencies updated: Regularly update Docker, devcontainer CLI, and Node.js
2. Use strong container names: Avoid special characters in container names
3. Monitor logs: Check security logs for suspicious activities
4. Validate inputs: Don't trust user inputs; validate all container selections
5. Use restrictive permissions: Ensure config directory has 0o700 permissions

Reporting Vulnerabilities

If you discover a security vulnerability, please report it responsibly by opening a private GitHub Security Advisory.

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

Development Setup

# Clone repository
git clone https://github.com/isupervillain/opencode-container-exec.git
cd opencode-container-exec

# Install dependencies
npm install

# Run tests
npm test

# Run tests in watch mode
npm run test:watch

Testing

# Run all tests
npm test

# Run specific test file
node --test test/unit/state.test.js

# Run tests with watch mode
npm run test:watch

Changelog

See CHANGELOG.md for version history.

License

MIT © isupervillain

Support

• Documentation: README.md
• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Security: Report via GitHub Security Advisory