Multi-Project Port Registry

When running multiple MITRE projects simultaneously, assign unique ports to avoid conflicts.

Default Behavior

Every project defaults to PostgreSQL on port 5432 and the app on port 3000. This works out of the box for single-project development. Only set custom ports if you run multiple projects at once.

Port Assignments

Project	PORT (app)	DATABASE_PORT
Vulcan	3000	5435

If you run other MITRE projects alongside Vulcan, assign them different ports in their own .env files to avoid conflicts.

Setup

Each project uses the same pattern: env vars with standard defaults.

1. Copy .env.example to .env
2. Set DATABASE_PORT and POSTGRES_PORT to the same value from the table above
3. Set PORT for the app server
4. docker compose up db -d
5. bin/rails db:prepare (or equivalent)

Example .env (Vulcan)

DATABASE_PORT=5435
DATABASE_HOST=127.0.0.1
DATABASE_GSSENCMODE=disable
POSTGRES_PORT=5435
PORT=3000

Environment Variable Naming Convention

All MITRE projects follow UPPERCASE_WITH_UNDERSCORES using full descriptive words:

Variable	Used By	Purpose
DATABASE_PORT	database.yml	PostgreSQL client connection port
DATABASE_HOST	database.yml	PostgreSQL host (default: 127.0.0.1)
DATABASE_GSSENCMODE	database.yml	GSSAPI encryption mode (set to disable on macOS with Kerberos)
DATABASE_URL	database.yml	Full connection string (12-factor, takes precedence in production)
POSTGRES_PORT	docker-compose.yml	Docker host-side port mapping (must match DATABASE_PORT)
POSTGRES_USER	docker-compose.yml	Docker PostgreSQL init: username to create
POSTGRES_PASSWORD	docker-compose.yml	Docker PostgreSQL init: password to set
POSTGRES_DB	docker-compose.yml	Docker PostgreSQL init: database to create
PORT	Procfile.dev	App server (Puma/Rails) listen port
DATABASE_NAME	database.yml	Override default database name

Why two port variables? DATABASE_PORT is what Rails uses to connect. POSTGRES_PORT is what Docker uses to map the container's internal port 5432 to the host. Set both to the same value in .env.

Why not PG* shorthand? PostgreSQL's libpq defines PGPORT, PGHOST, etc. but our project convention uses full descriptive words with underscores (DATABASE_PORT, VULCAN_ENABLE_OIDC, etc.) for consistency and readability across all MITRE projects.

OrbStack / k8s Note

OrbStack's built-in Kubernetes can shadow port 5432 on the host. If docker logs shows no incoming connections but Rails reports connection errors, another PostgreSQL is intercepting traffic. Assign a different port.