node-lambda/lib/s3_deploy.js

'use strict'

const crypto = require('crypto')
// https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3.html#createBucket-property
const S3_LOCATION_POSSIBLE_VALUES = [
  'EU',
  'ap-northeast-1',
  'ap-south-1',
  'ap-southeast-1',
  'ap-southeast-2',
  'cn-north-1',
  'eu-central-1',
  'eu-west-1',
  'sa-east-1',
  'us-west-1',
  'us-west-2'
]

class S3Deploy {
  constructor (aws, region) {
    // Authenticated `aws` object in `lib/main.js`
    this.s3 = new aws.S3({
      region: region,
      apiVersion: '2006-03-01'
    })
  }

  _md5 (str) {
    return crypto
      .createHash('md5')
      .update(str, 'utf8')
      .digest('hex')
  }

  _convertRegionStringToEnvVarName (region) {
    if (region == null) return 'undefined'
    return region.replace(/-/g, '_').toUpperCase()
  }

  _getBucketNameFromEnvVar (region) {
    const key = [
      'S3',
      this._convertRegionStringToEnvVarName(region),
      'BUCKET'
    ].join('_')
    return process.env[key]
  }

  _getS3KeyPrefixFromEnvVar (region) {
    const key = [
      'S3',
      this._convertRegionStringToEnvVarName(region),
      'PREFIX'
    ].join('_')
    return process.env[key]
  }

  _bucketName (params) {
    const bucketNameFromEnvVar = this._getBucketNameFromEnvVar(params.region)
    if (bucketNameFromEnvVar != null) return bucketNameFromEnvVar

    return [
      params.FunctionName,
      params.region,
      this._md5(params.FunctionName + params.region)
    ]
      .join('-')
      .substr(0, 63)
  }

  _s3Key (params) {
    const s3Prefix = this._getS3KeyPrefixFromEnvVar(params.region)
    const keys = [`deploy-package-${params.FunctionName}.zip`]
    if (s3Prefix != null) {
      keys.unshift(s3Prefix.replace(/\/$/, ''))
    }
    return keys.join('/')
  }

  _getS3Location (region) {
    return S3_LOCATION_POSSIBLE_VALUES.includes(region) ? region : null
  }

  _createBucket (params) {
    const _params = {
      Bucket: params.bucketName
    }
    const s3Locatoin = this._getS3Location(params.region)
    if (s3Locatoin != null) {
      _params.CreateBucketConfiguration = {
        LocationConstraint: s3Locatoin
      }
    }
    return new Promise((resolve, reject) => {
      this.s3.createBucket(_params, (err, data) => {
        if (err) {
          // Ignored created
          if (err.code === 'BucketAlreadyOwnedByYou') return resolve({})
          return reject(err)
        }
        resolve(data)
      })
    })
  }

  _putObject (params, buffer) {
    const _params = {
      Body: buffer,
      Bucket: params.bucketName,
      Key: params.s3Key
    }
    return new Promise((resolve, reject) => {
      this.s3.putObject(_params, (err, data) => {
        if (err) reject(err)
        resolve(data)
      })
    })
  }

  putPackage (params, region, buffer) {
    const _params = Object.assign({region: region}, params)
    _params.bucketName = this._bucketName(_params)
    _params.s3Key = this._s3Key(_params)

    return this._createBucket(_params).then((result) => {
      if (result.Location != null) {
        console.log('=> S3 Bucket created:')
        console.log(`===> ${_params.bucketName}`)
      }
      return this._putObject(_params, buffer)
    }).then((result) => {
      console.log('=> Deploy the zip file to S3:')
      console.log(`===> ${_params.bucketName}/${_params.s3Key}`)
      return {
        S3Bucket: _params.bucketName,
        S3Key: _params.s3Key
      }
    })
  }
}

module.exports = S3Deploy