flyio-core-workflow-b

name	flyio-core-workflow-b
description	Execute Fly.io secondary workflow: Postgres clusters, persistent volumes, and private networking. Use when adding databases, persistent storage, or internal service communication. Trigger: "fly postgres", "fly volumes", "fly.io database", "fly.io persistent storage".
allowed-tools	Read, Write, Edit, Bash(fly:*), Bash(psql:*), Grep
version	1.6.0
license	MIT
author	Jeremy Longshore <[e-mail]>
tags	["saas","edge-compute","flyio"]
compatibility	Designed for Claude Code

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

# 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

# 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

# fly.toml
[mounts]
  source = "data"
  destination = "/data"

# Deploy to pick up mount
fly deploy

# Verify mount inside machine
fly ssh console -C "df -h /data"

Step 3: Private Networking (6PN)

# 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://postgres:[e-mail]:5432/my_db

// Access internal services (no public internet)
const dbUrl = ;
 apiUrl = ;