TypeError when dd_extension is idle and/or misconfigured

[scheuk]

Expected Behavior

No error and function works as expected without traces and logs being collected

Actual Behavior

The execution breaks with an stacktrace

Steps to Reproduce the Problem

1. Configure a lambda function with the datadog tracing
2. Set DD_API_KEY_SECRET_ARN to an invalid secret
3. invoke function

Specifications

• Datadog Lambda Layer version: 82? DD_EXTENSION | DEBUG | Starting Datadog Extension 82
• Node version: 18

Stacktrace

{
  "stack": "Runtime.UnhandledPromiseRejection: TypeError: Converting circular structure to JSON\n    --> starting at object with constructor 'TLSSocket'\n    |     property '_httpMessage' -> object with constructor 'ClientRequest'\n    --- property 'socket' closes the circle\n    at process.<anonymous> (file:///var/runtime/index.mjs:1329:17)\n    at process.emit (node:events:529:35)\n    at process.emit (node:domain:489:12)\n    at emit (node:internal/process/promises:149:20)\n    at processPromiseRejections (node:internal/process/promises:283:27)\n    at process.processTicksAndRejections (node:internal/process/task_queues:96:32)",
  "message": "TypeError: Converting circular structure to JSON\n    --> starting at object with constructor 'TLSSocket'\n    |     property '_httpMessage' -> object with constructor 'ClientRequest'\n    --- property 'socket' closes the circle",
  "reason": {
      "stack": "TypeError: Converting circular structure to JSON\n    --> starting at object with constructor 'TLSSocket'\n    |     property '_httpMessage' -> object with constructor 'ClientRequest'\n    --- property 'socket' closes the circle\n    at JSON.stringify (<anonymous>)\n    at emitLog (/var/task/node_modules/datadog-lambda-js/dist/utils/log.js:73:20)\n    at logError (/var/task/node_modules/datadog-lambda-js/dist/utils/log.js:48:5)\n    at MetricsListener.<anonymous> (/var/task/node_modules/datadog-lambda-js/dist/metrics/listener.js:310:46)\n    at step (/var/task/node_modules/datadog-lambda-js/dist/metrics/listener.js:56:23)\n    at Object.throw (/var/task/node_modules/datadog-lambda-js/dist/metrics/listener.js:37:53)\n    at rejected (/var/task/node_modules/datadog-lambda-js/dist/metrics/listener.js:29:65)\n    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)",
      "message": "Converting circular structure to JSON\n    --> starting at object with constructor 'TLSSocket'\n    |     property '_httpMessage' -> object with constructor 'ClientRequest'\n    --- property 'socket' closes the circle"
  },
  "promise": {}
}

[scheuk]

Extension log:

2025-07-23T15:02:06.415Z | DD_EXTENSION \| DEBUG \| Logging subsystem enabled
2025-07-23T15:02:06.415Z | DD_EXTENSION \| DEBUG \| FIPS mode is disabled
2025-07-23T15:02:06.415Z | DD_EXTENSION \| DEBUG \| Starting Datadog Extension 82
2025-07-23T15:02:06.464Z | DD_EXTENSION \| DEBUG \| Decrypt took 46ms
2025-07-23T15:02:06.464Z | DD_EXTENSION \| ERROR \| Error decrypting key: {"Message":"User: arn:aws:sts::*********:assumed-role/some_role is not authorized to perform: secretsmanager:GetSecretValue on resource: arn:aws:secretsmanager:us-east-1:***********:secret:datadog-apm-RVdwrQ-foo because no identity-based policy allows the secretsmanager:GetSecretValue action","__type":"AccessDeniedException"}
  | 2025-07-23T15:02:06.464Z | DD_EXTENSION \| ERROR \| Failed to resolve secrets, Datadog extension will be idle

[astuyve]

hi @scheuk, I'm having trouble trying to reproduce this. I receive a similar error from the extension but do not see a log from this library:

Are you using any custom distribution metrics or something which may cause this library to fail sending data directly back to datadog?

Thanks!
AJ

[litianningdatadog]

hi @scheuk I did some tests w/ various runtime but only got the same result as what @astuyve shared above. We could not reproduce the error TypeError: Converting circular structure to JSON, which indicates a circular reference in object. Recommend doing further investigation on your end if possible?

[scheuk]

I am doing something in our code, we are wrapping the winston library and I have some code that will attempt to jsonfy a stack/error message:

if not ('toJSON' in Error.prototype)
  Object.defineProperty(Error.prototype, 'toJSON',
    value: ->
      obj = {}
      for prop in Object.getOwnPropertyNames(@)
        obj[prop] = @[prop]
      return obj
  )

PS this is coffeescript