mirror of
https://github.com/aminnairi/dotfiles.git
synced 2026-09-14 16:52:12 +02:00
configuration for the docker skill for opencode
This commit is contained in:
aminnairi
@@ -0,0 +1,560 @@
|
||||
---
|
||||
name: docker
|
||||
description: Docker containerization - images, containers, volumes, networking, docker-compose, best practices
|
||||
metadata:
|
||||
language: bash
|
||||
audience: developers
|
||||
---
|
||||
|
||||
## Overview
|
||||
|
||||
Docker is a platform for developing, shipping, and running applications in containers. Use this skill when working with Docker or Docker Compose.
|
||||
|
||||
## Installation
|
||||
|
||||
### Docker Engine
|
||||
|
||||
```bash
|
||||
# Ubuntu/Debian
|
||||
sudo apt update
|
||||
sudo apt install docker.io
|
||||
sudo systemctl start docker
|
||||
sudo systemctl enable docker
|
||||
|
||||
# Add user to docker group
|
||||
sudo usermod -aG docker $USER
|
||||
```
|
||||
|
||||
### Docker Compose
|
||||
|
||||
```bash
|
||||
# Standalone (recommended)
|
||||
sudo curl -L "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
|
||||
sudo chmod +x /usr/local/bin/docker-compose
|
||||
```
|
||||
|
||||
Verify installation:
|
||||
```bash
|
||||
docker --version
|
||||
docker-compose --version
|
||||
```
|
||||
|
||||
## Basic Concepts
|
||||
|
||||
### Images
|
||||
|
||||
- **Image**: A read-only template for creating containers
|
||||
- **Container**: A runnable instance of an image
|
||||
- **Tag**: Version identifier for images (e.g., `nginx:latest`)
|
||||
- **Registry**: Storage for images (Docker Hub, GHCR, ECR, etc.)
|
||||
|
||||
### Common Commands
|
||||
|
||||
```bash
|
||||
# List images
|
||||
docker images
|
||||
docker image ls
|
||||
|
||||
# Pull an image
|
||||
docker pull nginx:latest
|
||||
|
||||
# Remove an image
|
||||
docker rmi nginx:latest
|
||||
|
||||
# Build an image from Dockerfile
|
||||
docker build -t myapp:latest .
|
||||
|
||||
# Tag an image
|
||||
docker tag myapp:latest registry.io/myapp:latest
|
||||
|
||||
# Push to registry
|
||||
docker push registry.io/myapp:latest
|
||||
```
|
||||
|
||||
## Docker Contexts
|
||||
|
||||
Docker contexts allow you to manage connections to multiple Docker hosts from a single Docker CLI. Useful for switching between local Docker, remote servers, or Kubernetes clusters.
|
||||
|
||||
### Basic Context Management
|
||||
|
||||
```bash
|
||||
# List all contexts
|
||||
docker context ls
|
||||
|
||||
# Show current context
|
||||
docker context show
|
||||
|
||||
# Use a specific context
|
||||
docker context use my-remote-host
|
||||
|
||||
# Create a new context
|
||||
docker context create my-remote-host \
|
||||
--docker "host=ssh://user@remote-server:22"
|
||||
|
||||
# Create context from existing Docker configuration
|
||||
docker context create my-context --docker "host=tcp://localhost:2375"
|
||||
|
||||
# Inspect a context
|
||||
docker context inspect my-remote-host
|
||||
|
||||
# Remove a context
|
||||
docker context rm my-remote-host
|
||||
```
|
||||
|
||||
### SSH Context
|
||||
|
||||
Connect to a remote Docker host via SSH:
|
||||
|
||||
```bash
|
||||
# Create SSH context
|
||||
docker context create production \
|
||||
--docker "host=ssh://user@production-server"
|
||||
|
||||
# Use the context
|
||||
docker context use production
|
||||
docker ps
|
||||
docker run -d nginx:latest
|
||||
```
|
||||
|
||||
### Kubernetes Context
|
||||
|
||||
```bash
|
||||
# List Kubernetes contexts (requires kubectl)
|
||||
kubectl config get-contexts
|
||||
|
||||
# Create Docker context from Kubernetes context
|
||||
docker context create k8s-prod \
|
||||
--kubernetes "context-name=production"
|
||||
|
||||
# Switch to Kubernetes context
|
||||
docker context use k8s-prod
|
||||
```
|
||||
|
||||
### Use with Docker Compose
|
||||
|
||||
```bash
|
||||
# Use a specific context with compose
|
||||
docker --context my-remote-host compose up -d
|
||||
|
||||
# Or set context in compose file (Docker Compose v2)
|
||||
COMPOSE_DOCKER_CLI_HOST=1 docker compose up -d
|
||||
```
|
||||
|
||||
### Best Practices
|
||||
|
||||
1. **Name meaningfully** - Use prefixes like `local-`, `prod-`, `dev-`
|
||||
2. **Test before switching** - Use `docker context inspect` to verify
|
||||
3. **Keep local default** - Keep `default` or `local` for local development
|
||||
4. **Document remote connections** - Note SSH keys and endpoints
|
||||
|
||||
```bash
|
||||
# Example context setup
|
||||
docker context create local # Local Docker (default)
|
||||
docker context create dev-server --docker "host=ssh://dev@dev-server"
|
||||
docker context create prod-server --docker "host=ssh://prod@prod-server"
|
||||
|
||||
# Quick switch
|
||||
docker context use dev-server
|
||||
```
|
||||
|
||||
## Dockerfile
|
||||
|
||||
### Best Practices
|
||||
|
||||
1. **Use multi-stage builds** - Reduce final image size
|
||||
2. **Order commands by change frequency** - Cache unchanged layers
|
||||
3. **Use specific tags** - Avoid `latest` in production
|
||||
4. **Use .dockerignore** - Exclude unnecessary files
|
||||
5. **Run as non-root** - Security best practice
|
||||
6. **Use official base images** - Better security and maintenance
|
||||
|
||||
### Node.js Example
|
||||
|
||||
```dockerfile
|
||||
# Build stage
|
||||
FROM node:20-alpine AS builder
|
||||
WORKDIR /app
|
||||
COPY package*.json ./
|
||||
RUN npm ci
|
||||
COPY . .
|
||||
RUN npm run build
|
||||
|
||||
# Production stage
|
||||
FROM node:20-alpine AS production
|
||||
WORKDIR /app
|
||||
COPY --from=builder /app/dist ./dist
|
||||
COPY --from=builder /app/node_modules ./node_modules
|
||||
USER node
|
||||
EXPOSE 3000
|
||||
CMD ["node", "dist/index.js"]
|
||||
```
|
||||
|
||||
### Python Example
|
||||
|
||||
```dockerfile
|
||||
FROM python:3.11-slim AS builder
|
||||
WORKDIR /app
|
||||
COPY requirements.txt .
|
||||
RUN pip install --user -r requirements.txt
|
||||
|
||||
FROM python:3.11-slim
|
||||
WORKDIR /app
|
||||
COPY --from=builder /root/.local /root/.local
|
||||
COPY . .
|
||||
ENV PATH=/root/.local/bin:$PATH
|
||||
EXPOSE 8000
|
||||
CMD ["python", "main.py"]
|
||||
```
|
||||
|
||||
### .dockerignore
|
||||
|
||||
```
|
||||
node_modules
|
||||
.git
|
||||
.gitignore
|
||||
.env
|
||||
.env.*
|
||||
README.md
|
||||
dist
|
||||
build
|
||||
coverage
|
||||
*.log
|
||||
.DS_Store
|
||||
```
|
||||
|
||||
## Containers
|
||||
|
||||
### Run a Container
|
||||
|
||||
```bash
|
||||
# Run in background (detached)
|
||||
docker run -d myapp:latest
|
||||
|
||||
# Run with port mapping
|
||||
docker run -d -p 8080:3000 myapp:latest
|
||||
|
||||
# Run with volume mount
|
||||
docker run -d -v /host/path:/container/path myapp:latest
|
||||
|
||||
# Run with environment variables
|
||||
docker run -d -e NODE_ENV=production -e API_KEY=xxx myapp:latest
|
||||
|
||||
# Run with name
|
||||
docker run -d --name my-container myapp:latest
|
||||
|
||||
# Interactive mode
|
||||
docker run -it ubuntu:latest /bin/bash
|
||||
|
||||
# Remove container after exit
|
||||
docker run --rm myapp:latest
|
||||
```
|
||||
|
||||
### Container Management
|
||||
|
||||
```bash
|
||||
# List running containers
|
||||
docker ps
|
||||
|
||||
# List all containers
|
||||
docker ps -a
|
||||
|
||||
# Stop a container
|
||||
docker stop my-container
|
||||
|
||||
# Start a stopped container
|
||||
docker start my-container
|
||||
|
||||
# Restart a container
|
||||
docker restart my-container
|
||||
|
||||
# Remove a container
|
||||
docker rm my-container
|
||||
|
||||
# Remove all stopped containers
|
||||
docker container prune
|
||||
|
||||
# View logs
|
||||
docker logs -f my-container
|
||||
|
||||
# Execute command in running container
|
||||
docker exec -it my-container sh
|
||||
|
||||
# Inspect container details
|
||||
docker inspect my-container
|
||||
|
||||
# View resource usage
|
||||
docker stats my-container
|
||||
```
|
||||
|
||||
## Volumes
|
||||
|
||||
### Named Volumes
|
||||
|
||||
```bash
|
||||
# Create a volume
|
||||
docker volume create my-data
|
||||
|
||||
# List volumes
|
||||
docker volume ls
|
||||
|
||||
# Inspect volume
|
||||
docker volume inspect my-data
|
||||
|
||||
# Remove volume
|
||||
docker volume rm my-data
|
||||
```
|
||||
|
||||
### Bind Mounts
|
||||
|
||||
```bash
|
||||
# Mount host directory
|
||||
docker run -v /host/path:/container/path myapp:latest
|
||||
|
||||
# Mount read-only
|
||||
docker run -v /host/path:/container/path:ro myapp:latest
|
||||
```
|
||||
|
||||
### Use in Dockerfile
|
||||
|
||||
```dockerfile
|
||||
VOLUME /app/data
|
||||
```
|
||||
|
||||
## Networking
|
||||
|
||||
### Networks
|
||||
|
||||
```bash
|
||||
# Create a network
|
||||
docker network create my-network
|
||||
|
||||
# List networks
|
||||
docker network ls
|
||||
|
||||
# Connect container to network
|
||||
docker network connect my-network my-container
|
||||
|
||||
# Disconnect container from network
|
||||
docker network disconnect my-network my-container
|
||||
```
|
||||
|
||||
### Port Exposure
|
||||
|
||||
```dockerfile
|
||||
EXPOSE 3000 8080
|
||||
```
|
||||
|
||||
## Docker Compose
|
||||
|
||||
### Basic Structure
|
||||
|
||||
```yaml
|
||||
version: '3.8'
|
||||
|
||||
services:
|
||||
app:
|
||||
build: .
|
||||
ports:
|
||||
- "3000:3000"
|
||||
environment:
|
||||
- NODE_ENV=production
|
||||
volumes:
|
||||
- ./data:/app/data
|
||||
depends_on:
|
||||
- db
|
||||
restart: unless-stopped
|
||||
|
||||
db:
|
||||
image: postgres:15-alpine
|
||||
environment:
|
||||
POSTGRES_DB: myapp
|
||||
POSTGRES_USER: user
|
||||
POSTGRES_PASSWORD: password
|
||||
volumes:
|
||||
- db-data:/var/lib/postgresql/data
|
||||
restart: unless-stopped
|
||||
|
||||
volumes:
|
||||
db-data:
|
||||
```
|
||||
|
||||
### Common Commands
|
||||
|
||||
```bash
|
||||
# Start services
|
||||
docker-compose up -d
|
||||
|
||||
# Start with build
|
||||
docker-compose up -d --build
|
||||
|
||||
# Stop services
|
||||
docker-compose down
|
||||
|
||||
# Stop and remove volumes
|
||||
docker-compose down -v
|
||||
|
||||
# View logs
|
||||
docker-compose logs -f
|
||||
|
||||
# List services
|
||||
docker-compose ps
|
||||
|
||||
# Execute command in service
|
||||
docker-compose exec app sh
|
||||
|
||||
# Scale a service
|
||||
docker-compose up -d --scale app=3
|
||||
```
|
||||
|
||||
### Healthchecks
|
||||
|
||||
```yaml
|
||||
services:
|
||||
app:
|
||||
build: .
|
||||
healthcheck:
|
||||
test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
|
||||
interval: 30s
|
||||
timeout: 10s
|
||||
retries: 3
|
||||
start_period: 40s
|
||||
```
|
||||
|
||||
### Profiles
|
||||
|
||||
```yaml
|
||||
services:
|
||||
app:
|
||||
build: .
|
||||
|
||||
debug:
|
||||
build: .
|
||||
profiles:
|
||||
- debug
|
||||
command: ["sleep", "infinity"]
|
||||
```
|
||||
|
||||
Run with profile: `docker-compose --profile debug up`
|
||||
|
||||
## Development
|
||||
|
||||
### Development with Volumes
|
||||
|
||||
```yaml
|
||||
services:
|
||||
app:
|
||||
build:
|
||||
context: .
|
||||
target: development
|
||||
volumes:
|
||||
- .:/app
|
||||
- /app/node_modules
|
||||
environment:
|
||||
- NODE_ENV=development
|
||||
command: npm run dev
|
||||
```
|
||||
|
||||
### Hot Reload
|
||||
|
||||
For Node.js with nodemon:
|
||||
```dockerfile
|
||||
FROM node:20-alpine
|
||||
WORKDIR /app
|
||||
COPY package*.json ./
|
||||
RUN npm install
|
||||
COPY . .
|
||||
CMD ["npm", "run", "dev"]
|
||||
```
|
||||
|
||||
## Security Best Practices
|
||||
|
||||
1. **Don't run as root** - Use `USER` directive
|
||||
2. **Scan for vulnerabilities** - Use `docker scout` or `trivy`
|
||||
3. **Use specific tags** - Not `latest`
|
||||
4. **Read-only containers** - Use `--read-only` flag
|
||||
5. **Limit capabilities** - Use `--cap-drop` and `--cap-add`
|
||||
6. **Secrets management** - Use Docker secrets or environment variables
|
||||
7. **Multi-stage builds** - Minimize attack surface
|
||||
|
||||
```bash
|
||||
# Security scanning
|
||||
docker scout cves myapp:latest
|
||||
|
||||
# Run securely
|
||||
docker run \
|
||||
--read-only \
|
||||
--cap-drop ALL \
|
||||
--user 1000:1000 \
|
||||
myapp:latest
|
||||
```
|
||||
|
||||
## Debugging
|
||||
|
||||
```bash
|
||||
# Interactive shell
|
||||
docker run -it --rm myapp:latest sh
|
||||
|
||||
# Inspect with dive (if installed)
|
||||
dive myapp:latest
|
||||
|
||||
# Check layers
|
||||
docker history myapp:latest
|
||||
|
||||
# Debug running container
|
||||
docker exec sh
|
||||
|
||||
# Copy files from -it my-container container
|
||||
docker cp my-container:/app/logs ./logs
|
||||
```
|
||||
|
||||
## Common Patterns
|
||||
|
||||
### Node.js + Nginx
|
||||
|
||||
```yaml
|
||||
services:
|
||||
app:
|
||||
build: ./app
|
||||
expose:
|
||||
- "3000"
|
||||
|
||||
nginx:
|
||||
image: nginx:alpine
|
||||
ports:
|
||||
- "80:80"
|
||||
volumes:
|
||||
- ./nginx.conf:/etc/nginx/nginx.conf:ro
|
||||
depends_on:
|
||||
- app
|
||||
```
|
||||
|
||||
### Database + Backup
|
||||
|
||||
```yaml
|
||||
services:
|
||||
db:
|
||||
image: postgres:15-alpine
|
||||
volumes:
|
||||
- db-data:/var/lib/postgresql/data
|
||||
|
||||
backup:
|
||||
image: postgres:15-alpine
|
||||
volumes:
|
||||
- ./backups:/backups
|
||||
command: >
|
||||
sh -c "while true; do
|
||||
pg_dump -h db -U postgres mydb > /backups/backup-$$(date +%Y%m%d-%H%M%S).sql;
|
||||
sleep 86400;
|
||||
done"
|
||||
depends_on:
|
||||
- db
|
||||
```
|
||||
|
||||
## Tips
|
||||
|
||||
- Use `docker system prune -a` to clean up unused resources
|
||||
- Use `--force-rm` when building to remove intermediate containers
|
||||
- Use `-f` flag to force operations
|
||||
- Use `--no-cache` for clean builds
|
||||
- Tag images before pushing to registries
|
||||
- Use `docker-compose config` to validate compose files
|
||||
Reference in New Issue
Block a user