devcontainer-setup

Files (10)

• SKILL.md
• openai.yaml · agents/
• trail-of-bits-mark.svg · assets/
• dockerfile-best-practices.md · references/
• features-vs-dockerfile.md · references/
• .zshrc · resources/
• Dockerfile · resources/
• devcontainer.json · resources/
• install.sh · resources/
• post_install.py · resources/

SKILL.md (first lines)

# Devcontainer Setup Skill

Creates a pre-configured devcontainer with Claude Code and language-specific tooling.

## When to Use

- User asks to "set up a devcontainer" or "add devcontainer support"
- User wants a sandboxed Claude Code development environment
- User needs isolated development environments with persistent configuration

## When NOT to Use

- User already has a devcontainer configuration and just needs modifications
- User is asking about general Docker or container questions
- User wants to deploy production containers (this is for development only)

## Workflow

```mermaid
flowchart TB
    start([User requests devcontainer])
    recon[1. Project Reconnaissance]
    detect[2. Detect Languages]
    generate[3. Generate Configuration]
    write[4. Write files to .devcontainer/]
    done([Done])

    start --> recon
    recon --> detect
    detect --> generate
    generate --> write
    write --> done
```

## Phase 1: Project Reconnaissance

### Infer Project Name

Check in order (use first match):

1. `package.json` → `name` field
2. `pyproject.toml` → `project.name`
3. `Cargo.toml` → `package.name`
4. `go.mod` → module path (last segment after `/`)
5. Directory name as fallback

Convert to slug: lowercase, replace spaces/underscores with hyphens.

### Detect Language Stack

| Language | Detection Files |
|----------|-----------------|
| Python | `pyproject.toml`, `*.py` |
| Node/TypeScript | `package.json`, `tsconfig.json` |
| Rust | `Cargo.toml` |
| Go | `go.mod`, `go.sum` |

### Multi-Language Projects

If multiple languages are detected, configure all of them in the following priority order:

1. **Python** - Primary language, uses Dockerfile for uv + Python installation
2. **Node/TypeScript** - Uses devcontainer feature
3. **Rust** - Uses devcontainer feature
4. **Go** - Uses devcontainer feature

For multi-language `postCreateCommand`, chain all setup commands:
```
uv run /opt/post_install.py && uv sync && npm ci
```

Extensions and settings from all detected languages should be merged into the configuration.

## Phase 2: Generate Configuration

Start with base templates from `resources/` directory. Substitute:

- `{{PROJECT_NAME}}` → Human-readable name (e.g., "My Project")
- `{{PROJECT_SLUG}}` → Slug for volumes (e.g., "my-project")

Then apply language-specific modifications below.

## Base Template Features

The base template includes:

- **Claude Code** with marketplace plugins (anthropics/skills, trailofbits/skills, trailofbits/skills-curated)
- **Sandboxing** via bubblewrap and socat
- **Python 3.13** via uv (fast binary download)
- **Node 22** via fnm (Fast Node Manager)
- **ast-grep** for AST-based code search
- **Network isolation tools** (iptables, ipset) with NET_ADMIN capability
- **Security mounts**: `.devcontainer/` mounted read-only to prevent container escape
- **Token forwarding**: `CLAUDE_CODE_OAUTH_TOKEN` and `ANTHROPIC_API_KEY` via `remoteEnv`
- **Modern CLI tools**: ripgrep, fd, fzf, tmux, git-delta

---

## Language-Specific Sections

### Python Projects

**Detection:** `pyproject.toml`, `requirements.txt`, `setup.py`, or `*.py` files

**Dockerfile additions:**

The base Dockerfile already includes Python 3.13 via uv. If a different version is required (detected from `pyproject.toml`), modify the Python installation:

```dockerfile
# Install Python via uv (fast binary download, not source compilation)
RUN uv python install <version> --default
```

**devcontainer.json extensions:**

Add to `customizations.vscode.extensions`:
```json
"ms-python.python",
"ms-python.vscode-pylance",

From trailofbits/skills, CC-BY-SA-4.0.

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