Docker Configuration

🐳 Docker Architecture

Container Structure

┌─────────────────────────────────────────┐
│ Load Balancer │
├─────────────────────────────────────────┤
│ Runner 1 │ Runner 2 │ Runner 3 │
├─────────────────────────────────────────┤
│ Monitoring Stack │
│ Prometheus │ Grafana │ AlertMgr │
├─────────────────────────────────────────┤
│ Shared Volumes │
│ Cache │ Workspace │ Logs │
└─────────────────────────────────────────┘

📁 Docker Compose Configuration

Basic Setup

# docker/docker-compose.yml
version: "3.8"
services:
 runner:
 build:
 context: .
 dockerfile: Dockerfile
 image: ghcr.io/grammatonic/github-runner:latest
 environment:
 - GITHUB_TOKEN=${GITHUB_TOKEN}
 - GITHUB_REPOSITORY=${GITHUB_REPOSITORY}
 - RUNNER_NAME=${RUNNER_NAME:-runner}
 - RUNNER_LABELS=${RUNNER_LABELS:-self-hosted,docker}
 volumes:
 - runner_workspace:/workspace
 - runner_cache:/cache
 - /var/run/docker.sock:/var/run/docker.sock:ro
 restart: unless-stopped
 deploy:
 resources:
 limits:
 memory: ${RUNNER_MEMORY_LIMIT:-2g}
 cpus: "${RUNNER_CPU_LIMIT:-1.0}"
 reservations:
 memory: 512m
 cpus: "0.25"
volumes:
 runner_workspace:
 driver: local
 runner_cache:
 driver: local
networks:
 default:
 name: ${DOCKER_NETWORK:-github-runner-network}

Production Configuration

# docker/docker-compose.prod.yml
version: "3.8"
services:
 runner:
 extends:
 file: docker-compose.yml
 service: runner
 deploy:
 replicas: 3
 restart_policy:
 condition: on-failure
 delay: 5s
 max_attempts: 3
 window: 120s
 resources:
 limits:
 memory: 4g
 cpus: "2.0"
 healthcheck:
 test: ["CMD", "/app/healthcheck.sh"]
 interval: 30s
 timeout: 10s
 retries: 3
 start_period: 40s
 # Monitoring services
 prometheus:
 image: prom/prometheus:latest
 profiles: ["monitoring"]
 ports:
 - "9090:9090"
 volumes:
 - ./monitoring/prometheus.yml:/etc/prometheus/prometheus.yml:ro
 - prometheus_data:/prometheus
 command:
 - "--config.file=/etc/prometheus/prometheus.yml"
 - "--storage.tsdb.path=/prometheus"
 - "--web.console.libraries=/etc/prometheus/console_libraries"
 - "--web.console.templates=/etc/prometheus/consoles"
 - "--web.enable-lifecycle"
 grafana:
 image: grafana/grafana:latest
 profiles: ["monitoring"]
 ports:
 - "3000:3000"
 environment:
 - GF_SECURITY_ADMIN_PASSWORD=${GRAFANA_PASSWORD:-admin}
 volumes:
 - grafana_data:/var/lib/grafana
 - ./monitoring/grafana/dashboards:/etc/grafana/provisioning/dashboards:ro
 - ./monitoring/grafana/datasources:/etc/grafana/provisioning/datasources:ro
volumes:
 prometheus_data:
 grafana_data:

🏗️ Dockerfile Optimization

Multi-Stage Build

# docker/Dockerfile
FROM ubuntu:22.04 as base
# Install basic dependencies
RUN apt-get update && apt-get install -y \
 curl \
 jq \
 git \
 wget \
 unzip \
 build-essential \
 && rm -rf /var/lib/apt/lists/*
# GitHub Actions Runner stage
FROM base as runner
ARG RUNNER_VERSION=2.328.0
ARG TARGETPLATFORM
# Create runner user
RUN useradd -m -s /bin/bash runner
# Download and install GitHub Actions runner
WORKDIR /actions-runner
RUN curl -o actions-runner-linux-x64-${RUNNER_VERSION}.tar.gz \
 -L https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-x64-${RUNNER_VERSION}.tar.gz \
 && tar xzf ./actions-runner-linux-x64-${RUNNER_VERSION}.tar.gz \
 && rm actions-runner-linux-x64-${RUNNER_VERSION}.tar.gz
# Install dependencies
RUN ./bin/installdependencies.sh
# Copy entrypoint script
COPY entrypoint.sh /entrypoint.sh
RUN chmod +x /entrypoint.sh
# Set ownership
RUN chown -R runner:runner /actions-runner
USER runner
WORKDIR /actions-runner
ENTRYPOINT ["/entrypoint.sh"]

Optimized Dockerfile

# Production-optimized version
FROM ubuntu:22.04 as builder
# Build tools and dependencies
RUN apt-get update && apt-get install -y \
 curl \
 wget \
 build-essential \
 && rm -rf /var/lib/apt/lists/*
# Download runner
ARG RUNNER_VERSION=2.328.0
WORKDIR /tmp
RUN curl -o actions-runner.tar.gz \
 -L https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-x64-${RUNNER_VERSION}.tar.gz
FROM ubuntu:22.04 as runtime
# Runtime dependencies only
RUN apt-get update && apt-get install -y \
 curl \
 jq \
 git \
 docker.io \
 && rm -rf /var/lib/apt/lists/* \
 && apt-get clean
# Create runner user
RUN useradd -m -s /bin/bash runner
# Copy runner from builder
WORKDIR /actions-runner
COPY --from=builder /tmp/actions-runner.tar.gz .
RUN tar xzf actions-runner.tar.gz && rm actions-runner.tar.gz
# Install runner dependencies
RUN ./bin/installdependencies.sh
# Security hardening
RUN chown -R runner:runner /actions-runner \
 && chmod -R 755 /actions-runner
USER runner

🔧 Environment Configuration

Development Environment

# config/docker.env.dev
DOCKER_BUILDKIT=1
COMPOSE_PROJECT_NAME=github-runner-dev
DOCKER_NETWORK=runner-dev-network
# Resource limits (development)
RUNNER_MEMORY_LIMIT=1g
RUNNER_CPU_LIMIT=0.5
# Logging
COMPOSE_LOG_LEVEL=INFO
DOCKER_LOG_DRIVER=json-file
DOCKER_LOG_OPTS_MAX_SIZE=10m
DOCKER_LOG_OPTS_MAX_FILE=3

Production Environment

# config/docker.env.prod
DOCKER_BUILDKIT=1
COMPOSE_PROJECT_NAME=github-runner-prod
DOCKER_NETWORK=runner-prod-network
# Resource limits (production)
RUNNER_MEMORY_LIMIT=4g
RUNNER_CPU_LIMIT=2.0
# High availability
RUNNER_REPLICAS=3
HEALTH_CHECK_INTERVAL=30s
RESTART_POLICY=unless-stopped
# Security
DOCKER_CONTENT_TRUST=1
DOCKER_REGISTRY=ghcr.io/grammatonic

📊 Volume Management

Cache Strategy

volumes:
 # Build cache
 build_cache:
 driver: local
 driver_opts:
 type: none
 o: bind
 device: /opt/runner-cache/build
 # Dependencies cache
 deps_cache:
 driver: local
 driver_opts:
 type: none
 o: bind
 device: /opt/runner-cache/deps
 # Workspace persistence
 workspace:
 driver: local
 driver_opts:
 type: none
 o: bind
 device: /opt/runner-workspace

Backup Configuration

# scripts/backup-volumes.sh
#!/bin/bash
BACKUP_DIR="/backup/$(date +%Y%m%d)"
mkdir -p "$BACKUP_DIR"
# Backup volumes
docker run --rm \
 -v github-runner_runner_workspace:/source:ro \
 -v "$BACKUP_DIR":/backup \
 alpine tar czf /backup/workspace.tar.gz -C /source .
docker run --rm \
 -v github-runner_runner_cache:/source:ro \
 -v "$BACKUP_DIR":/backup \
 alpine tar czf /backup/cache.tar.gz -C /source .

🌐 Network Configuration

Custom Network Setup

networks:
 frontend:
 driver: bridge
 ipam:
 config:
 - subnet: 172.20.0.0/24
 backend:
 driver: bridge
 internal: true
 ipam:
 config:
 - subnet: 172.21.0.0/24
services:
 runner:
 networks:
 - frontend
 - backend
 prometheus:
 networks:
 - backend

Load Balancer Configuration

# nginx load balancer
nginx:
 image: nginx:alpine
 ports:
 - "80:80"
 - "443:443"
 volumes:
 - ./nginx/nginx.conf:/etc/nginx/nginx.conf:ro
 - ./nginx/ssl:/etc/ssl/certs:ro
 depends_on:
 - runner

🔍 Health Checks

Runner Health Check

#!/bin/bash
# docker/healthcheck.sh
# Check if runner process is running
if ! pgrep -f "Runner.Listener" > /dev/null; then
 echo "Runner process not found"
 exit 1
fi
# Check if runner can connect to GitHub
if ! curl -s -f https://api.github.com/user > /dev/null 2>&1; then
 echo "Cannot connect to GitHub API"
 exit 1
fi
# Check disk space
DISK_USAGE=$(df /workspace | tail -1 | awk '{print 5ドル}' | sed 's/%//')
if [ "$DISK_USAGE" -gt 90 ]; then
 echo "Disk usage too high: ${DISK_USAGE}%"
 exit 1
fi
echo "Health check passed"
exit 0

Docker Compose Health Check

healthcheck:
 test: ["CMD", "/app/healthcheck.sh"]
 interval: 30s
 timeout: 10s
 retries: 3
 start_period: 40s

🚀 Performance Optimization

Build Cache Optimization

# Use BuildKit cache mounts
RUN --mount=type=cache,target=/var/cache/apt \
 --mount=type=cache,target=/var/lib/apt \
 apt-get update && apt-get install -y \
 build-essential \
 python3-dev

Resource Monitoring

# Monitor resource usage
docker stats --format "table {{.Container}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.MemPerc}}"
# Container resource limits
docker inspect runner | jq '.[0].HostConfig.Memory'
docker inspect runner | jq '.[0].HostConfig.CpuQuota'

🔄 Next Steps