mqtt5 multi-initialization workaround for Lambda

[SlavenIvanov]

Hello,

We are trying to use aws-iot-device-sdk-js-v2 library in AWS Lambda, because of missing features in the v3 js sdk (mainly subscribing to an mqtt topic).

We have created a file that makes a singleton out of an mqtt5 client:

const cfg = {
  endpoint: '213421342134-ats.iot.2341234.amazonaws.com',
  key: fs.readFileSync(path.resolve(__dirname, 'slaven-osx-thing-private.pem.key'), 'utf8'),
  cert: fs.readFileSync(path.resolve(__dirname, 'slaven-osx-thing-certificate.pem.crt'), 'utf8')
}

const builder = iot.AwsIotMqtt5ClientConfigBuilder.newDirectMqttBuilderWithMtlsFromMemory(cfg.endpoint, cfg.cert, cfg.key)
const config: mqtt5.Mqtt5ClientConfig = builder.build()

export const client = new mqtt5.Mqtt5Client(config)

And then we import it into a Lambda handler:

export const handler = async () => {
  const connectionSuccess = once(client, 'connectionSuccess')
  client.start()
  await connectionSuccess
  console.log('🟢Connected to AWS IoT')

  const stopped = once(client, 'stopped')
  client.stop()
  await stopped
  console.log('Stopped client')

  client.close()
  console.log('Closed client')

   ....
}

The first time we call the Lambda everything goes as expected. The client connects, then disconnects
The second time we call it we get this:

"Error: Aws-crt-nodejs does not yet support multi-initialization.",
        "at Object.Module._extensions..node (node:internal/modules/cjs/loader:1189:18)",
        "at Module.load (node:internal/modules/cjs/loader:981:32)",
        "at Function.Module._load (node:internal/modules/cjs/loader:822:12)",
        "at Module.require (node:internal/modules/cjs/loader:1005:19)",
        "at require (node:internal/modules/cjs/helpers:102:18)",
        "at Object.<anonymous> (/Users/slavi/git/growy/growy-v3-lcm/node_modules/aws-crt/dist/native/binding.js:59:19)",
        "at Module._compile (node:internal/modules/cjs/loader:1105:14)",
        "at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)",
        "at Module.load (node:internal/modules/cjs/loader:981:32)"

Does anyone have any ideas on a workaround?

[bretambrose]

Multi-initialization was resolved in https://github.com/awslabs/aws-crt-nodejs/releases/tag/v1.15.17
A related issue where node would crash when unloading the CRT's native code from a worker thread was resolved in https://github.com/awslabs/aws-crt-nodejs/releases/tag/v1.15.19