Compose

Docker Compose User Guide

Master advanced configurations, orchestration patterns, and troubleshooting techniques.

Deep Dive into YAML Networking Guide Troubleshoot Apps

Advanced YAML Configuration

Environment Variables

Use .env files or directly define variables in your YAML: 

services:
  web:
    image: my-app
    environment:
      - ENV_VAR1=${VAL1}
      - ENV_VAR2=my-default

Tip: Use env_file in services to load custom .env configurations.

Extending Compose Files

Use extends to inherit configurations across multiple services or environments. 

services:
  db:
    extends:
      file: common-compose.yml
      service: base-database

Combines modular configurations for DRY setups.

Note: Always prefix environment-specific values with COMPOSE_ to avoid conflicts in multi-project setups.

Custom Network Configurations

Isolated Networks

Create custom networks for security and performance. 

networks:
  frontend:
    driver: bridge
    ipam:
      config:
        - subnet: 172.20.0.0/16
  backend:
    driver: host

Choose host mode for low-latency services or overlay for swarm clusters.

Inter-Container Communication

Configure links or aliases for service discovery. 

services:
  app:
    networks:
      - frontend
    links:
      - db:database
  db:
    networks:
      frontend:
        aliases:
          - mysql

Network Troubleshooting

Use these commands to inspect connections:

View network topology
docker-compose network ls
Inspect container connections
docker-compose ps -n

Common Issues & Solutions

Service Startup Failures

If services fail to start, inspect logs first:

docker-compose logs web

Volume Mount Errors

Make sure mount points exist:

docker-compose config

Validate mount paths match host/container permissions.

Need production-grade help? Upgrade to Docker Pro for 24/7 support.

Optimizing Compose for Production

Image Size

  • Use alpine variants
  • Multi-stage builds
  • Tag with :latest sparingly

Health Checks

Add to services to avoid false readiness:

healthcheck: test: curl -f http://localhost || exit 1

Resource Limits

Apply CPU/Memory constraints to prevent resource starvation:

deploy: resources: limits: cpus: '2' memory: 2G

Got production-scale questions?

Our enterprise engineers are available for advanced help and training sessions.

Contact Experts →