server/initializers/migrator.js

   1 'use strict'
   2
   3 const eachSeries = require('async/eachSeries')
   4 const fs = require('fs')
   5 const path = require('path')
   6
   7 const constants = require('./constants')
   8 const db = require('./database')
   9 const logger = require('../helpers/logger')
  10
  11 const migrator = {
  12   migrate: migrate
  13 }
  14
  15 function migrate (callback) {
  16   db.Application.loadMigrationVersion(function (err, actualVersion) {
  17     if (err) return callback(err)
  18
  19     // If there are a new migration scripts
  20     if (actualVersion < constants.LAST_MIGRATION_VERSION) {
  21       logger.info('Begin migrations.')
  22
  23       getMigrationScripts(function (err, migrationScripts) {
  24         if (err) return callback(err)
  25
  26         eachSeries(migrationScripts, function (entity, callbackEach) {
  27           executeMigration(actualVersion, entity, callbackEach)
  28         }, function (err) {
  29           if (err) return callback(err)
  30
  31           logger.info('Migrations finished. New migration version schema: %s', constants.LAST_MIGRATION_VERSION)
  32           return callback(null)
  33         })
  34       })
  35     } else {
  36       return callback(null)
  37     }
  38   })
  39 }
  40
  41 // ---------------------------------------------------------------------------
  42
  43 module.exports = migrator
  44
  45 // ---------------------------------------------------------------------------
  46
  47 function getMigrationScripts (callback) {
  48   fs.readdir(path.join(__dirname, 'migrations'), function (err, files) {
  49     if (err) return callback(err)
  50
  51     const filesToMigrate = []
  52
  53     files.forEach(function (file) {
  54       // Filename is something like 'version-blabla.js'
  55       const version = file.split('-')[0]
  56       filesToMigrate.push({
  57         version,
  58         script: file
  59       })
  60     })
  61
  62     return callback(err, filesToMigrate)
  63   })
  64 }
  65
  66 function executeMigration (actualVersion, entity, callback) {
  67   const versionScript = entity.version
  68
  69   // Do not execute old migration scripts
  70   if (versionScript <= actualVersion) return callback(null)
  71
  72   // Load the migration module and run it
  73   const migrationScriptName = entity.script
  74   logger.info('Executing %s migration script.', migrationScriptName)
  75
  76   const migrationScript = require(path.join(__dirname, 'migrations', migrationScriptName))
  77
  78   db.sequelize.transaction().asCallback(function (err, t) {
  79     if (err) return callback(err)
  80
  81     migrationScript.up({ transaction: t }, function (err) {
  82       if (err) {
  83         t.rollback()
  84         return callback(err)
  85       }
  86
  87       // Update the new migration version
  88       db.Application.updateMigrationVersion(versionScript, t, function (err) {
  89         if (err) {
  90           t.rollback()
  91           return callback(err)
  92         }
  93
  94         t.commit()
  95       })
  96     })
  97   })
  98 }