⭐ Docker Orchestration

Docker Orchestration is the subsystem responsible for generating, managing, and executing Docker Compose configurations for all database engines. It acts as the execution layer beneath StartActions, transforming engine‑specific provisioning logic into runnable container definitions with predictable behavior, secure defaults, and consistent resource handling.

This page explains how Docker Orchestration works, how Compose files are generated, how containers are started, and how orchestration integrates with the rest of the platform.

Purpose of Docker Orchestration The Docker Orchestration subsystem provides:

Deterministic container startup

Engine‑specific Compose generation

Secure volume mounting

Network configuration

Healthcheck integration

Resource limit enforcement

TLS/SSL mounting

Environment variable injection

It ensures every database engine is launched in a consistent, reproducible manner.

How Docker Orchestration Fits Into the System StartActions generate:

Environment variables

Volume definitions

SSL directories

Config directories

Runtime flags

Healthchecks

Docker Orchestration takes these components and produces:

A complete Docker Compose service

A runnable container

A predictable startup lifecycle

Orchestration Workflow mermaid flowchart TD A[StartAction] --> B[Generate Compose] B --> C[Provisioning Engine] C --> D[Create Volumes] D --> E[Create Container] E --> F[Start Container] F --> G[Run Healthcheck] G --> H[Mark Database Running]

1. Compose Generation Each StartAction produces a structured Compose definition containing:

Image Engine‑specific image:

mysql:

postgres:

redis:

eqalpha/keydb:

dragonflydb/dragonfly:

mongo:

Ports Mapped from the database configuration:

Code 3306:3306 (MySQL/MariaDB) 5432:5432 (PostgreSQL) 6379:6379 (Redis/KeyDB/Dragonfly) 27017:27017 (MongoDB) Volumes Persistent directories:

Data directory

SSL directory

Config directory

Keyfile directory (MongoDB)

Environment Variables Normalized by the StartAction.

Persistent directories:

Data directory

SSL directory

Config directory

Keyfile directory (MongoDB)

Environment Variables Normalized by the StartAction.

Healthcheck Engine‑specific commands:

mysqladmin ping

pg_isready

redis-cli ping

keydb-cli ping

dragonfly ping

mongo --eval "db.adminCommand('ping')"

Runtime Flags Engine‑specific options:

MySQL authentication plugin

PostgreSQL TLS settings

Redis/KeyDB/Dragonfly TLS flags

MongoDB keyfile + TLS flags

2. Provisioning Engine The provisioning engine receives the Compose definition and:

Creates volumes

Writes config files

Writes SSL certificates

Writes keyfiles (MongoDB)

Prepares directories

Normalizes permissions

This ensures the container has everything it needs before startup.

3. Container Creation Docker Orchestration uses the Compose definition to:

Create the container

Attach networks

Mount volumes

Inject environment variables

Apply runtime flags

This step ensures the container is fully configured before running.

4. Container Startup The container is started with:

Engine‑specific runtime flags

TLS configuration

Authentication configuration

Config file paths

Volume mounts

Startup behavior is deterministic across all engines.

5. Healthcheck Execution After startup, the healthcheck runs until the engine reports readiness.

Examples:

Code mysqladmin ping -h localhost pg_isready -U postgres redis-cli ping keydb-cli ping dragonfly ping mongo --eval "db.adminCommand('ping')" If the healthcheck fails repeatedly, the provisioning engine marks the database as failed.

6. Database Ready State Once the healthcheck passes:

The database is marked as running

Connection details are stored

SSL paths are stored

Environment variables are finalized

The instance is now ready for client connections.

Example Compose Snippet (Conceptual) services: mysql: image: mysql:8.0 ports: - "3306:3306" environment: MYSQL_ROOT_PASSWORD: "${MYSQL_ROOT_PASSWORD}" volumes: - /data/coolify/mysql//data:/var/lib/mysql - /data/coolify/ssl/:/etc/mysql/ssl healthcheck: test: ["CMD", "mysqladmin", "ping", "-h", "localhost"] interval: 10s timeout: 5s retries: 5

Why Docker Orchestration Matters Docker Orchestration ensures:

Predictable container startup

Secure mounting of sensitive files

Consistent behavior across engines

Automatic TLS integration

Automatic healthchecks

Reproducible deployments

Clean separation between provisioning logic and execution logic

It is the backbone of the entire database provisioning system.