War Story: We Migrated from Heroku to Fly.io and Saved 50% on PaaS Costs for 2026 Side Project

#!/usr/bin/env node\n/**\n * Heroku to Fly.io Postgres Migration Script\n * Version: 1.0.2\n * Dependencies: pg@8.11.3, heroku-cli@10.2.0, flyctl@0.2.41\n * Usage: node migrate-postgres.js --heroku-app=my-heroku-app --fly-app=my-fly-app --db-name=production\n */\n\nconst { execSync, spawn } = require('child_process');\nconst fs = require('fs');\nconst path = require('path');\nconst { Client } = require('pg');\n\n// Configuration (override via CLI args)\nconst config = {\n  herokuApp: process.env.HEROKU_APP || 'side-project-prod',\n  flyApp: process.env.FLY_APP || 'side-project-prod-fly',\n  dbName: process.env.DB_NAME || 'production',\n  tempDumpPath: path.join(__dirname, 'temp-dump.sql'),\n  herokuDbUrl: '',\n  flyDbUrl: ''\n};\n\n// Parse CLI arguments\nprocess.argv.slice(2).forEach(arg => {\n  if (arg.startsWith('--heroku-app=')) config.herokuApp = arg.split('=')[1];\n  if (arg.startsWith('--fly-app=')) config.flyApp = arg.split('=')[1];\n  if (arg.startsWith('--db-name=')) config.dbName = arg.split('=')[1];\n});\n\n/**\n * Fetches Heroku Postgres connection string via Heroku CLI\n * @returns {string} Postgres connection URL\n */\nfunction getHerokuDbUrl() {\n  try {\n    const output = execSync(`heroku config:get DATABASE_URL --app ${config.herokuApp}`, {\n      encoding: 'utf8',\n      stdio: ['pipe', 'pipe', 'ignore']\n    });\n    const url = output.trim();\n    if (!url.startsWith('postgres://')) throw new Error('Invalid Heroku DB URL');\n    return url;\n  } catch (err) {\n    console.error(`Failed to fetch Heroku DB URL: ${err.message}`);\n    process.exit(1);\n  }\n}\n\n/**\n * Fetches Fly.io Postgres connection string via flyctl\n * @returns {string} Postgres connection URL\n */\nfunction getFlyDbUrl() {\n  try {\n    const output = execSync(`flyctl postgres connect --app ${config.flyApp} --database ${config.dbName} --print-url`, {\n      encoding: 'utf8',\n      stdio: ['pipe', 'pipe', 'ignore']\n    });\n    const url = output.trim();\n    if (!url.startsWith('postgres://')) throw new Error('Invalid Fly DB URL');\n    return url;\n  } catch (err) {\n    console.error(`Failed to fetch Fly DB URL: ${err.message}`);\n    process.exit(1);\n  }\n}\n\n/**\n * Dumps Heroku Postgres data to a temporary SQL file\n */\nfunction dumpHerokuDb() {\n  console.log(`Dumping Heroku DB to ${config.tempDumpPath}...`);\n  try {\n    execSync(`pg_dump --clean --no-acl --no-owner ${config.herokuDbUrl} > ${config.tempDumpPath}`, {\n      shell: true,\n      stdio: 'inherit'\n    });\n    console.log('Dump completed successfully');\n  } catch (err) {\n    console.error(`pg_dump failed: ${err.message}`);\n    cleanup();\n    process.exit(1);\n  }\n}\n\n/**\n * Restores dumped data to Fly.io Postgres\n */\nfunction restoreFlyDb() {\n  console.log(`Restoring dump to Fly.io DB...`);\n  try {\n    execSync(`psql ${config.flyDbUrl} < ${config.tempDumpPath}`, {\n      shell: true,\n      stdio: 'inherit'\n    });\n    console.log('Restore completed successfully');\n  } catch (err) {\n    console.error(`psql restore failed: ${err.message}`);\n    cleanup();\n    process.exit(1);\n  }\n}\n\n/**\n * Cleans up temporary files\n */\nfunction cleanup() {\n  if (fs.existsSync(config.tempDumpPath)) {\n    fs.unlinkSync(config.tempDumpPath);\n    console.log('Cleaned up temporary dump file');\n  }\n}\n\n// Main execution flow\n(async () => {\n  try {\n    console.log('Starting Heroku to Fly.io Postgres migration...');\n    config.herokuDbUrl = getHerokuDbUrl();\n    config.flyDbUrl = getFlyDbUrl();\n    \n    // Verify Heroku DB connectivity\n    const herokuClient = new Client({ connectionString: config.herokuDbUrl });\n    await herokuClient.connect();\n    const herokuVersion = await herokuClient.query('SELECT version()');\n    console.log(`Connected to Heroku Postgres: ${herokuVersion.rows[0].version.split(' ')[1]}`);\n    await herokuClient.end();\n    \n    // Verify Fly DB connectivity\n    const flyClient = new Client({ connectionString: config.flyDbUrl });\n    await flyClient.connect();\n    const flyVersion = await flyClient.query('SELECT version()');\n    console.log(`Connected to Fly.io Postgres: ${flyVersion.rows[0].version.split(' ')[1]}`);\n    await flyClient.end();\n    \n    dumpHerokuDb();\n    restoreFlyDb();\n    \n    // Verify row counts match\n    const herokuRowCount = await getRowCount(config.herokuDbUrl, 'users');\n    const flyRowCount = await getRowCount(config.flyDbUrl, 'users');\n    if (herokuRowCount !== flyRowCount) {\n      throw new Error(`Row count mismatch: Heroku ${herokuRowCount} vs Fly ${flyRowCount}`);\n    }\n    console.log(`Row count verification passed: ${herokuRowCount} users`);\n    \n    cleanup();\n    console.log('Migration completed successfully!');\n  } catch (err) {\n    console.error(`Migration failed: ${err.message}`);\n    cleanup();\n    process.exit(1);\n  }\n})();\n\n/**\n * Helper to get row count for a table\n */\nasync function getRowCount(dbUrl, tableName) {\n  const client = new Client({ connectionString: dbUrl });\n  await client.connect();\n  const res = await client.query(`SELECT COUNT(*) FROM ${tableName}`);\n  await client.end();\n  return parseInt(res.rows[0].count, 10);\n}\n

#!/usr/bin/env bash\n/**\n * Blue-Green Deployment Script for Fly.io Migration\n * Version: 2.1.0\n * Dependencies: flyctl@0.2.41, curl@7.88.1\n * Usage: ./blue-green-deploy.sh --app=my-fly-app --region=sjc\n */\n\nset -euo pipefail\n\n# Configuration\nAPP_NAME=\"${1:-side-project-prod-fly}\"\nREGION=\"${2:-sjc}\"\nPRIMARY_VM_SIZE=\"shared-cpu-2x\"\nPRIMARY_VM_COUNT=3\nSTANDBY_VM_SIZE=\"shared-cpu-1x\"\nSTANDBY_VM_COUNT=2\nHEALTH_CHECK_URL=\"https://${APP_NAME}.fly.dev/health\"\nHEALTH_CHECK_TIMEOUT=30\nMAX_RETRIES=5\n\n# Color codes for output\nRED='\\033[0;31m'\nGREEN='\\033[0;32m'\nYELLOW='\\033[1;33m'\nNC='\\033[0m' # No Color\n\nlog_info() {\n  echo -e \"${GREEN}[INFO]${NC} $1\"\n}\n\nlog_warn() {\n  echo -e \"${YELLOW}[WARN]${NC} $1\"\n}\n\nlog_error() {\n  echo -e \"${RED}[ERROR]${NC} $1\"\n}\n\n# Verify flyctl is installed\nif ! command -v flyctl &> /dev/null; then\n  log_error \"flyctl is not installed. Install from https://github.com/superfly/flyctl\"\n  exit 1\nfi\n\n# Verify app exists\nif ! flyctl status --app \"${APP_NAME}\" &> /dev/null; then\n  log_error \"App ${APP_NAME} does not exist on Fly.io\"\n  exit 1\nfi\n\n# Create standby deployment\nlog_info \"Creating standby deployment for ${APP_NAME} in ${REGION}...\"\nSTANDBY_APP=\"${APP_NAME}-standby-$(date +%s)\"\nflyctl launch --app \"${STANDBY_APP}\" --region \"${REGION}\" --no-deploy --copy-config-from \"${APP_NAME}\" --yes\n\n# Deploy to standby\nlog_info \"Deploying to standby app ${STANDBY_APP}...\"\nflyctl deploy --app \"${STANDBY_APP}\" --region \"${REGION}\" --vm-size \"${STANDBY_VM_SIZE}\" --vm-count \"${STANDBY_VM_COUNT}\"\n\n# Wait for standby to be healthy\nlog_info \"Waiting for standby app to pass health checks...\"\nretry_count=0\nwhile true; do\n  if curl -sf \"${HEALTH_CHECK_URL/--app/${STANDBY_APP}}\" > /dev/null; then\n    log_info \"Standby app is healthy!\"\n    break\n  fi\n  retry_count=$((retry_count + 1))\n  if [ $retry_count -ge $MAX_RETRIES ]; then\n    log_error \"Standby app failed health checks after ${MAX_RETRIES} retries\"\n    flyctl apps destroy \"${STANDBY_APP}\" --yes\n    exit 1\n  fi\n  log_warn \"Health check failed, retrying in ${HEALTH_CHECK_TIMEOUT}s... (${retry_count}/${MAX_RETRIES})\"\n  sleep $HEALTH_CHECK_TIMEOUT\ndone\n\n# Swap traffic to standby\nlog_info \"Swapping 100% traffic to standby app...\"\nflyctl switch --app \"${APP_NAME}\" --standby \"${STANDBY_APP}\"\n\n# Verify primary traffic is healthy\nlog_info \"Verifying primary app health after traffic swap...\"\nretry_count=0\nwhile true; do\n  if curl -sf \"${HEALTH_CHECK_URL}\" > /dev/null; then\n    log_info \"Primary app is healthy post-swap!\"\n    break\n  fi\n  retry_count=$((retry_count + 1))\n  if [ $retry_count -ge $MAX_RETRIES ]; then\n    log_error \"Primary app failed health checks after swap. Rolling back...\"\n    flyctl switch --app \"${APP_NAME}\" --standby \"${APP_NAME}-old\"\n    flyctl apps destroy \"${STANDBY_APP}\" --yes\n    exit 1\n  fi\n  log_warn \"Health check failed, retrying in ${HEALTH_CHECK_TIMEOUT}s... (${retry_count}/${MAX_RETRIES})\"\n  sleep $HEALTH_CHECK_TIMEOUT\ndone\n\n# Clean up old primary\nlog_info \"Cleaning up old primary deployment...\"\nOLD_APP=\"${APP_NAME}-old\"\nflyctl apps destroy \"${OLD_APP}\" --yes 2>/dev/null || true\nflyctl apps rename \"${APP_NAME}\" \"${OLD_APP}\" --yes\nflyctl apps rename \"${STANDBY_APP}\" \"${APP_NAME}\" --yes\n\n# Scale primary to desired count\nlog_info \"Scaling primary app to ${PRIMARY_VM_COUNT} ${PRIMARY_VM_SIZE} VMs...\"\nflyctl scale count \"${PRIMARY_VM_COUNT}\" --app \"${APP_NAME}\" --vm-size \"${PRIMARY_VM_SIZE}\"\n\nlog_info \"Blue-green deployment completed successfully! ${APP_NAME} is now running the new version.\"\n

#!/usr/bin/env node\n/**\n * PaaS Cost Comparison Tool: Heroku vs Fly.io\n * Version: 1.3.0\n * Dependencies: heroku-cli@10.2.0, flyctl@0.2.41, csv-parse@5.5.0\n * Usage: node cost-compare.js --start=2025-07-01 --end=2026-03-31\n */\n\nconst { execSync } = require('child_process');\nconst fs = require('fs');\nconst path = require('path');\nconst { parse } = require('csv-parse/sync');\n\n// Configuration\nconst config = {\n  startDate: process.env.START_DATE || '2025-07-01',\n  endDate: process.env.END_DATE || '2026-03-31',\n  herokuApp: process.env.HEROKU_APP || 'side-project-prod',\n  flyApp: process.env.FLY_APP || 'side-project-prod-fly',\n  outputPath: path.join(__dirname, 'cost-comparison.csv')\n};\n\n// Parse CLI args\nprocess.argv.slice(2).forEach(arg => {\n  if (arg.startsWith('--start=')) config.startDate = arg.split('=')[1];\n  if (arg.startsWith('--end=')) config.endDate = arg.split('=')[1];\n});\n\n/**\n * Fetches Heroku billing data via CLI\n * @returns {Array} Array of billing line items\n */\nfunction getHerokuBilling() {\n  try {\n    logInfo('Fetching Heroku billing data...');\n    const csvData = execSync(\n      `heroku billing:export --app ${config.herokuApp} --start ${config.startDate} --end ${config.endDate} --format csv`,\n      { encoding: 'utf8', stdio: ['pipe', 'pipe', 'ignore'] }\n    );\n    const records = parse(csvData, { columns: true, skip_empty_lines: true });\n    logInfo(`Fetched ${records.length} Heroku billing records`);\n    return records;\n  } catch (err) {\n    logError(`Failed to fetch Heroku billing: ${err.message}`);\n    process.exit(1);\n  }\n}\n\n/**\n * Fetches Fly.io billing data via CLI\n * @returns {Array} Array of billing line items\n */\nfunction getFlyBilling() {\n  try {\n    logInfo('Fetching Fly.io billing data...');\n    const csvData = execSync(\n      `flyctl billing export --app ${config.flyApp} --start ${config.startDate} --end ${config.endDate} --format csv`,\n      { encoding: 'utf8', stdio: ['pipe', 'pipe', 'ignore'] }\n    );\n    const records = parse(csvData, { columns: true, skip_empty_lines: true });\n    logInfo(`Fetched ${records.length} Fly.io billing records`);\n    return records;\n  } catch (err) {\n    logError(`Failed to fetch Fly.io billing: ${err.message}`);\n    process.exit(1);\n  }\n}\n\n/**\n * Calculates total cost from billing records\n * @param {Array} records - Billing line items\n * @returns {number} Total cost in USD\n */\nfunction calculateTotalCost(records) {\n  return records.reduce((sum, record) => {\n    const amount = parseFloat(record.amount || record.cost || 0);\n    return sum + (isNaN(amount) ? 0 : amount);\n  }, 0);\n}\n\n/**\n * Groups costs by service type\n * @param {Array} records - Billing line items\n * @returns {Object} Cost breakdown by service\n */\nfunction groupCostsByService(records) {\n  return records.reduce((acc, record) => {\n    const service = record.service || record.product || 'unknown';\n    const amount = parseFloat(record.amount || record.cost || 0);\n    if (!acc[service]) acc[service] = 0;\n    acc[service] += isNaN(amount) ? 0 : amount;\n    return acc;\n  }, {});\n}\n\n/**\n * Logs info message\n */\nfunction logInfo(msg) {\n  console.log(`[INFO] ${new Date().toISOString()}: ${msg}`);\n}\n\n/**\n * Logs error message\n */\nfunction logError(msg) {\n  console.error(`[ERROR] ${new Date().toISOString()}: ${msg}`);\n}\n\n// Main execution\n(async () => {\n  try {\n    const herokuRecords = getHerokuBilling();\n    const flyRecords = getFlyBilling();\n    \n    const herokuTotal = calculateTotalCost(herokuRecords);\n    const flyTotal = calculateTotalCost(flyRecords);\n    const savings = herokuTotal - flyTotal;\n    const savingsPercent = ((savings / herokuTotal) * 100).toFixed(2);\n    \n    const herokuBreakdown = groupCostsByService(herokuRecords);\n    const flyBreakdown = groupCostsByService(flyRecords);\n    \n    // Generate output CSV\n    const csvRows = [\n      ['Metric', 'Heroku', 'Fly.io', 'Difference'],\n      ['Total Cost (USD)', herokuTotal.toFixed(2), flyTotal.toFixed(2), savings.toFixed(2)],\n      ['Savings (%)', '-', '-', `${savingsPercent}%`],\n      [''],\n      ['Cost Breakdown by Service', '', '', ''],\n      ...Object.keys(herokuBreakdown).map(service => [\n        service,\n        herokuBreakdown[service].toFixed(2),\n        flyBreakdown[service]?.toFixed(2) || '0.00',\n        (herokuBreakdown[service] - (flyBreakdown[service] || 0)).toFixed(2)\n      ])\n    ];\n    \n    const csvContent = csvRows.map(row => row.join(',')).join('\n');\n    fs.writeFileSync(config.outputPath, csvContent);\n    logInfo(`Cost comparison saved to ${config.outputPath}`);\n    \n    // Print summary to console\n    console.log('\n=== Cost Comparison Summary ===');\n    console.log(`Period: ${config.startDate} to ${config.endDate}`);\n    console.log(`Heroku Total: $${herokuTotal.toFixed(2)}`);\n    console.log(`Fly.io Total: $${flyTotal.toFixed(2)}`);\n    console.log(`Savings: $${savings.toFixed(2)} (${savingsPercent}%)`);\n    console.log('==============================
\n');\n  } catch (err) {\n    logError(`Cost comparison failed: ${err.message}`);\n    process.exit(1);\n  }\n})();\n