Docker Skill

# Docker — Install and Use Containers

Enables OpenClaw (and Cursor) to install Docker and use it reliably. Base all guidance on official Docker docs; when in doubt, fetch from canonical URLs below.

When to Apply

• User wants to install Docker (macOS, Linux, Windows)
• User asks about containers, images, Dockerfile, docker compose
• Building, running, or debugging Docker commands or workflows
• User asks for "latest Docker docs" or "how do I use Docker"

Canonical Documentation URLs

| Purpose | URL | |--------|-----| | Get started / overview | https://docs.docker.com/get-started/overview/ | | Get Docker (install) | https://docs.docker.com/get-started/get-docker/ | | Develop with containers | https://docs.docker.com/get-started/introduction/develop-with-containers/ | | Guides | https://docs.docker.com/guides/ | | Manuals (install, config, use) | https://docs.docker.com/manuals/ | | Reference (CLI, Dockerfile, API) | https://docs.docker.com/reference/ | | Engine install (Linux) | https://docs.docker.com/engine/install/ | | Docker Desktop Mac | https://docs.docker.com/desktop/install/mac-install/ | | Docker CLI reference | https://docs.docker.com/reference/cli/docker/ | | Dockerfile reference | https://docs.docker.com/reference/dockerfile/ |

Rule: For install steps, CLI syntax, or Dockerfile instructions, fetch the relevant doc URL and use that content. Do not rely on training data for version-specific install or command details.

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Installation (Reliable Paths)

macOS

Recommended: Docker Desktop

1. Download from official docs: Install Docker Desktop on Mac.
2. - Apple Silicon: `https://desktop.docker.com/mac/main/arm64/Docker.dmg`
3. - Intel: `https://desktop.docker.com/mac/main/amd64/Docker.dmg`
4. Open `Docker.dmg`, drag Docker to Applications, then open Docker.app and accept terms.
5. CLI install (optional): After downloading the DMG:
6. ```bash
7. sudo hdiutil attach Docker.dmg
8. sudo /Volumes/Docker/Docker.app/Contents/MacOS/install
9. sudo hdiutil detach /Volumes/Docker
10. ```
11. Verify: `docker run hello-world`

OpenClaw / automation: If `docker` is missing and the user is on macOS, suggest installing via Homebrew: `brew install --cask docker`, then starting Docker Desktop so the daemon is running.

Linux (Ubuntu example)

1. Prefer Docker Engine from apt (see Install Docker Engine on Ubuntu).
2. Remove conflicting packages first:
3. ```bash
4. sudo apt remove $(dpkg --get-selections docker.io docker-compose docker-compose-v2 docker-doc podman-docker containerd runc 2>/dev/null | cut -f1)
5. ```
6. Add Docker’s apt repo, then:
7. ```bash
8. sudo apt update
9. sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
10. sudo systemctl start docker
11. sudo docker run hello-world
12. ```
13. Optional (run without sudo): Linux postinstall — add user to `docker` group.

Convenience script (dev/test only): `curl -fsSL https://get.docker.com -o get-docker.sh && sudo sh get-docker.sh`. Not recommended for production.

Windows

Use Get Docker and follow Docker Desktop for Windows (WSL2 backend recommended).

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Core Workflow: Build and Run

1. Dockerfile in app directory (see reference.md or Dockerfile reference).
2. Build image: `docker build -t <name> .`
3. Run container: `docker run -d -p HOST_PORT:CONTAINER_PORT <name>` (e.g. `-p 127.0.0.1:3000:3000`).
4. List containers: `docker ps` (running), `docker ps -a` (all).
5. Stop/remove: `docker stop <container>`, `docker rm <container>`.

Example from official getting-started:

```bash docker build -t getting-started . docker run -d -p 127.0.0.1:3000:3000 getting-started # Open http://localhost:3000 ```

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Daemon Must Be Running

• Docker Desktop (Mac/Windows): Ensure Docker Desktop app is running; `docker` CLI talks to its daemon.
• Linux: `sudo systemctl start docker` (and `enable` if needed).
• If the user sees "Cannot connect to the Docker daemon", direct them to start Docker Desktop or the engine service and try again.

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Quick Reference

• Images: `docker pull <image>`, `docker images`, `docker rmi <image>`
• Containers: `docker run`, `docker ps`, `docker stop`, `docker rm`, `docker logs <container>`
• Compose: `docker compose up -d`, `docker compose down` — use `compose.yaml` in project root (see Compose file reference).
• Cleanup: `docker system prune -a` (removes unused images/containers/networks; use with care).

Additional Resources

• For detailed CLI and Dockerfile syntax, see reference.md.
• For full specs, fetch from the official reference and guides.