/xdevcontainer

description: Set up Anthropic's official devcontainer for running Claude Code with --dangerously-skip-permissions safely
tags: [devcontainer, security, isolation, docker, autonomous, permissions]

Set up a secure devcontainer environment based on Anthropic's official reference implementation.

Reference: https://docs.anthropic.com/en/docs/claude-code/devcontainer

First, check the current environment and any existing configuration: !ls -la .devcontainer/ 2>/dev/null || echo "No existing devcontainer configuration" !which docker 2>/dev/null && docker --version || echo "Docker not installed" !which devcontainer 2>/dev/null && devcontainer --version || echo "devcontainer CLI not installed" !echo "ANTHROPIC_API_KEY is $([ -n \"$ANTHROPIC_API_KEY\" ] && echo 'set' || echo 'NOT SET')"

Based on $ARGUMENTS, perform the appropriate devcontainer operation:

1. Create Devcontainer (default, --create, --setup)

If creating a new devcontainer configuration or no arguments provided:

Recommended Security Configuration

Create `.devcontainer/devcontainer.json`:

{
  "name": "Claude Code Sandbox",
  "build": {
    "dockerfile": "Dockerfile"
  },
  "features": {
    "ghcr.io/devcontainers/features/node:1": {},
    "ghcr.io/devcontainers/features/python:1": {},
    "ghcr.io/devcontainers/features/git:1": {},
    "ghcr.io/devcontainers/features/github-cli:1": {},
    "ghcr.io/devcontainers/features/aws-cli:1": {},
    "ghcr.io/devcontainers/features/docker-in-docker:1": {}
  },
  "postCreateCommand": "npm install -g @anthropic-ai/claude-code && pip install --user boto3 requests",
  "remoteEnv": {
    "ANTHROPIC_API_KEY": "${localEnv:ANTHROPIC_API_KEY}",
    "GITHUB_TOKEN": "${localEnv:GITHUB_TOKEN}",
    "AWS_ACCESS_KEY_ID": "${localEnv:AWS_ACCESS_KEY_ID}",
    "AWS_SECRET_ACCESS_KEY": "${localEnv:AWS_SECRET_ACCESS_KEY}",
    "AWS_DEFAULT_REGION": "${localEnv:AWS_DEFAULT_REGION}"
  },
  "runArgs": [
    "--cap-drop=ALL",
    "--security-opt=no-new-privileges"
  ],
  "mounts": [],
  "customizations": {
    "vscode": {
      "extensions": [
        "anthropic.claude-code"
      ],
      "settings": {
        "terminal.integrated.defaultProfile.linux": "bash"
      }
    }
  }
}

Create `.devcontainer/Dockerfile`:

# Anthropic's recommended devcontainer for Claude Code
# Reference: https://docs.anthropic.com/en/docs/claude-code/devcontainer
FROM mcr.microsoft.com/devcontainers/base:ubuntu

# Security labels
LABEL org.opencontainers.image.title="Claude Code Sandbox"
LABEL org.opencontainers.image.description="Secure container for running Claude Code with --dangerously-skip-permissions"
LABEL org.opencontainers.image.vendor="Generated by setup-devcontainer.sh"

# Install essential security tools
RUN apt-get update && apt-get install -y \
    curl \
    ca-certificates \
    gnupg \
    lsb-release \
    && apt-get clean && rm -rf /var/lib/apt/lists/*

# Network firewall - only allow specific domains
RUN apt-get update && apt-get install -y iptables dnsutils && \
    apt-get clean && rm -rf /var/lib/apt/lists/*

# Create firewall setup script (runs at container start)
# Rules are processed in order - first match wins
RUN echo '#!/bin/bash' > /usr/local/bin/setup-firewall.sh && \
    echo 'set -e' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -o lo -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p udp --dport 53 -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p tcp --dport 53 -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p tcp -d api.anthropic.com --dport 443 -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p tcp -d github.com --dport 443 -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p tcp -d registry.npmjs.org --dport 443 -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p tcp -d pypi.org --dport 443 -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p tcp -d files.pythonhosted.org --dport 443 -j ACCEPT' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p tcp --dport 443 -j DROP' >> /usr/local/bin/setup-firewall.sh && \
    echo 'iptables -A OUTPUT -p tcp --dport 80 -j DROP' >> /usr/local/bin/setup-firewall.sh && \
    chmod +x /usr/local/bin/setup-firewall.sh

# Create non-root user workspace
RUN mkdir -p /workspace && chown vscode:vscode /workspace
WORKDIR /workspace

# Default to non-root user
USER vscode

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
    CMD curl -sf https://api.anthropic.com/health || exit 1

Key security features:

• **`--cap-drop=ALL`**: Drops all Linux capabilities
• **`--security-opt=no-new-privileges`**: Prevents privilege escalation
• **Network firewall**: Only allows traffic to allowlisted domains
• **No mounts**: Isolates from host filesystem

2. Using the Setup Script (--script)

If the user wants to use the automated setup script: !ls -la setup-devcontainer.sh 2>/dev/null || echo "Script not in current directory"

Run the setup script:

# Full setup with recommended security
./setup-devcontainer.sh

# Minimal setup (Node.js and Git only)
./setup-devcontainer.sh --minimal

# Skip network firewall restrictions
./setup-devcontainer.sh --no-network-firewall

# Preview what would be created
./setup-devcontainer.sh --dry-run

# Strict mode for CI (fails if prerequisites missing)
./setup-devcontainer.sh --strict

# Add custom domains for enterprise private registries
./setup-devcontainer.sh --allow-domain internal.registry.com

# Or use environment variable for extra domains
DEVCONTAINER_EXTRA_DOMAINS="internal.registry.com,npm.mycompany.com" ./setup-devcontainer.sh

3. Start Container (--start,