@sap/cds-mtxs/srv/cf/saas-provisioning-service.js

SAP Cloud Application Programming Model - Multitenancy library

const cds = require('@sap/cds/lib')
const LOG = cds.log('mtx'), DEBUG = cds.debug('mtx')

module.exports = class SaasProvisioningService extends require('./abstract-provisioning-service') {

  async init() {
    this.on('UPDATE', 'tenant', this._create)
    this.on('READ', 'tenant', super._read)
    this.on('DELETE', 'tenant', super._delete)
    this.on('getAppUrl', super._getAppUrl)
    this.on('dependencies', super._dependencies)
    this.on('upgrade', super._upgrade)
    super.init()
  }

  async _create(context) {
    if (context.data.eventType === 'UPDATE' && cds.requires['cds.xt.SaasProvisioningService']?.alwaysUpgradeModel === false) {
      const { headers } = cds.context?.http?.req ?? {}
      const { isSync } = this._parseHeaders(headers)
      // reject async use case for now, rarely used
      if (!isSync) throw new cds.error({ message: 'Synchronous processing required when using "alwaysUpgradeModel: false"', code: 422 })
      const sps = await cds.connect.to(this.name)
      return sps.getAppUrl(context.data, context.headers)
    }
    return super._create(context, context.data)
  }

  _parseHeaders(headers) {
    const { prefer, status_callback, mtx_status_callback } = headers ?? {}
    const { saas_registry_url } = this._getCredentials()
    const callbackUrl = mtx_status_callback ?? (status_callback && saas_registry_url && new URL(status_callback, saas_registry_url).toString())
    return {
      callbackUrl,
      isCustomCallback: !!mtx_status_callback,
      saasCallbackUrlPath: status_callback,
      isSync: !(prefer?.includes('respond-async') || callbackUrl)
    }
  }

  async _sendCallback(status, message, subscriptionUrl) {
    const { body, headers } = cds.context?.http?.req ?? {}
    const { isSync, isCustomCallback, saasCallbackUrlPath, callbackUrl } = this._parseHeaders(headers)
    if (!isSync && callbackUrl) {
      const tenant = this._getSubscribedTenant(body)
      const payload = { status, message, subscriptionUrl }
      let customPayload // additional payload for internal callback (java)
      if (isCustomCallback) {
        customPayload = { saasRequestPayload: body, saasCallbackUrl: saasCallbackUrlPath, tenant }
      }
      DEBUG?.('sending callback to', callbackUrl)
      try {
        const authHeader = isCustomCallback ? headers.authorization : `Bearer ${await this._token()}`
        await this.sendResult(callbackUrl, payload, customPayload, authHeader)
      } catch (error) {
        LOG.error(error)
      }
    }
  }
}