paulund/docker

Core Workflow

1. Define services — each service gets its own named block with image, ports, volumes, environment
2. Add healthchecks — on any service that others depend on being ready (databases, caches, search)
3. Set depends_on conditions — use service_healthy for services with healthchecks, service_completed_successfully for migration jobs
4. Configure networking — use custom networks to isolate internal services from public-facing ones
5. Separate environments — use override files to keep base config clean and environment differences explicit

Reference Guide

| Topic | Reference | Load When | |-------|-----------|-----------| | Healthchecks | references/healthchecks.md | Configuring healthcheck commands, timing, depends_on conditions | | Networking | references/networking.md | Custom networks, service DNS, port exposure vs publishing | | Volumes | references/volumes.md | Named volumes, bind mounts, tmpfs, sharing between services | | Environment | references/environment.md | .env files, variable substitution, secrets, env_file | | Profiles | references/profiles.md | Optional services (Mailpit, Adminer) toggled with --profile | | Override Files | references/override.md | Per-environment compose files for dev, CI, and production |

Constraints

MUST DO

• Add healthchecks to any service that dependent containers connect to (MySQL, Redis, Postgres)
• Use service_healthy in depends_on whenever a healthcheck is defined on the target service
• Use service_completed_successfully for one-off jobs (migrations, seed scripts)
• Use custom networks to prevent databases being reachable from public-facing services
• Use expose for internal ports, ports only for services that need host access
• Add .env and docker-compose.override.yml to .gitignore
• Commit .env.example and docker-compose.override.yml.example as templates

MUST NOT DO

• Use service_started for databases — a running container is not a ready database
• Hardcode secrets in the compose file — use .env or Docker secrets
• Use bind mounts in production
• Publish database ports in production compose files