flyio-core-workflow-b

# Fly.io Core Workflow B: Postgres, Volumes & Networking ## Overview Set up Fly Postgres, persistent Fly Volumes, and private networking between apps. Fly Postgres runs as a regular Fly app with automated replication. Volumes provide persistent NVMe storage attached to specific machines. ## Instructions ### Step 1: Create Fly Postgres ```bash # Create a Postgres cluster fly postgres create --name my-db --region iad --vm-size shared-cpu-1x --volume-size 10 # Attach to your app (sets DATABASE_URL secret automatically) fly postgres attach my-db -a my-app # Connect directly fly postgres connect -a my-db # psql> SELECT version(); # Proxy to local machine for dev tools fly proxy 5432 -a my-db # Now connect: psql postgres://postgres:password@localhost:5432 ``` ### Step 2: Create Persistent Volumes ```bash # Create a volume (same region as your machine) fly volumes create data --size 10 --region iad -a my-app # List volumes fly volumes list -a my-app # Mount in fly.toml ``` ```toml # fly.toml [mounts] source = "data" destination = "/data" ``` ```bash # Deploy to pick up mount fly deploy # Verify mount inside machine fly ssh console -C "df -h /data" ``` ### Step 3: Private Networking (6PN) ```bash # Apps in the same org can reach each other via .internal DNS # my-app can reach my-db at: my-db.internal:5432 # Internal DNS format: <app-name>.internal # Machine-specific: <machine-id>.vm.<app-name>.internal # Example: connect from app code DATABASE_URL=postgres://po...