What I do
- Containerize applications using Docker and containerd
- Optimize Docker images for size and security
- Configure multi-stage builds for efficient deployments
- Set up private container registries
- Implement container security scanning
- Build containerized development workflows
When to use me
- When packaging applications for deployment
- When creating consistent development environments
- When migrating applications to Kubernetes
- When optimizing application delivery
- When implementing microservices
- When building CI/CD pipelines
Key Concepts
Dockerfile Best Practices
# Multi-stage build for Go application
# Build stage
FROM golang:1.21-alpine AS builder
WORKDIR /app
# Install dependencies first for better caching
COPY go.mod go.sum ./
RUN go mod download
# Copy source code
COPY . .
# Build binary
RUN CGO_ENABLED=0 GOOS=linux go build \
-a -installsuffix cgo \
-o main .
# Production stage
FROM alpine:3.18
# Install certificates
RUN apk --no-cache add ca-certificates
# Create non-root user
RUN adduser -D -u 1000 appuser
WORKDIR /app
# Copy binary from builder
COPY --from=builder /app/main .
# Switch to non-root user
USER appuser
EXPOSE 8080
CMD ["./main"]
Docker Compose
version: '3.8'
services:
app:
build:
context: .
dockerfile: Dockerfile
ports:
- "8080:8080"
environment:
- DATABASE_URL=postgres://db:5432/app
- REDIS_URL=redis://cache:6379
depends_on:
db:
condition: service_healthy
cache:
condition: service_started
networks:
- backend
deploy:
resources:
limits:
cpus: '0.5'
memory: 512M
db:
image: postgres:15-alpine
volumes:
- postgres_data:/var/lib/postgresql/data
environment:
POSTGRES_DB: app
POSTGRES_USER: user
POSTGRES_PASSWORD: password
healthcheck:
test: ["CMD-SHELL", "pg_isready -U user -d app"]
interval: 5s
timeout: 5s
retries: 5
networks:
- backend
cache:
image: redis:7-alpine
networks:
- backend
volumes:
postgres_data:
networks:
backend:
driver: bridge
Image Optimization
# Use specific tags, not latest
FROM node:20-alpine
# Use .dockerignore
# node_modules
# .git
# *.md
# tests/
# Combine RUN commands
RUN apk add --no-cache \
&& rm -rf /var/cache/apk/*
# Don't run as root
USER node
# Use COPY, not ADD (unless extracting archives)
COPY --chown=node:node package*.json ./
RUN npm ci --only=production
# Health check
HEALTHCHECK --interval=30s --timeout=3s \
CMD wget --quiet --tries=1 --spider http://localhost:3000/health || exit 1
Security Scanning
# Scan for vulnerabilities
trivy image myapp:latest
# Scan with severity filter
trivy image --severity HIGH,CRITICAL myapp:latest
# Scan in CI/CD
docker scout cves myapp:latest
# Sysbox for secure containers
docker run --runtime=sysbox-runc myapp:latest
Registry Configuration
# Docker config for private registry
{
"auths": {
"registry.example.com": {
"username": "deploy",
"password": "${REGISTRY_PASSWORD}"
}
},
"experimental": "disabled",
"debug": "false"
}
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