TypeError due to missing sanitizeFieldNamesRegExp

[d0ruk]

Hello,

I am initialising the APM client at the top of my main module like so

const config = require('./config');
const { log } = require('./helpers');

if (config.apm.enabled) {
  require('elastic-apm-node').start({
    serviceName: config.apm.serviceName,
    secretToken: config.apm.secretToken,
    serverUrl: config.apm.serverUrl,
    serviceVersion: config.version,
    environment: config.apm.environment,
    captureBody: 'errors',
    logUncaughtExceptions: false,
  });
}

However, app crashes with a TypeError: Cannot read property 'push' of undefined referring to sanitizeFieldNamesRegExp.

I do not specify sanitizeFieldNames or sanitizeFieldNamesRegExp in the options, as seen above. The library then uses the default values which are initialized as arrays.

Do you have any idea as to why this happens?

---

The require('./config') that come before has

require('dotenv').config();
const env = { ...process.env };

Can this be where the problem is?

I'd appreciate any help/comments on this issue.

Note: I am using elastic-apm-node ^3.42.0 on Node.js 14.

Best,
Doruk

[trentm]

@d0ruk Thanks for the issue! I'll start trying to reproduce this.

Are you able to post the full traceback? Perhaps add the logUncaughtExceptions: true config var to the .start(...) options because the APM agent doesn't print uncaught exception tracebacks by default (it will in the next major version).

[d0ruk]

@trentm

Here is the stack.

TypeError: Cannot read property 'push' of undefined
  File "/home/node/node_modules/elastic-apm-node/lib/config.js", line 902, col 37, in normalizeSanitizeFieldNames
    opts.sanitizeFieldNamesRegExp.push(re)
  File "/home/node/node_modules/elastic-apm-node/lib/config.js", line 735, col 3, in normalize
    normalizeSanitizeFieldNames(opts)
  File "/home/node/node_modules/elastic-apm-node/lib/config.js", line 498, col 13, in Client.<anonymous>
    normalize(conf, agent.logger)
  File "events.js", line 400, col 28, in Client.emit
  File "domain.js", line 475, col 12, in Client.emit
  File "/home/node/node_modules/elastic-apm-http-client/index.js", line 427, col 14, in <anonymous>
    this.emit('config', config)
  File "/home/node/node_modules/fast-stream-to-buffer/index.js", line 20, col 9, in IncomingMessage.<anonymous>
    cb(err, buffers[0], stream)
  File "/home/node/node_modules/once/once.js", line 25, col 25, in IncomingMessage.f
    return f.value = fn.apply(this, arguments)
  File "/home/node/node_modules/end-of-stream/index.js", line 36, col 27, in IncomingMessage.onend
    if (!writable) callback.call(stream);
  File "events.js", line 412, col 35, in IncomingMessage.emit
  File "domain.js", line 475, col 12, in IncomingMessage.emit
  File "internal/streams/readable.js", line 1333, col 12, in endReadableNT
  File "internal/process/task_queues.js", line 82, col 21, in processTicksAndRejections

This error was captured on Node.js 14.19.3 with elastic-apm-http-client 11.2.0 & elastic-apm-node 3.43.0.

[trentm]

@d0ruk

That is a code path coming from Central config. Thanks very much, that traceback is helpful! I can reproduce the error and will work on a fix now.

I suspect you have APM Agent central config setup in your Kibana to configure sanitize_field_names for this or all services. Can you confirm that?
If you run your app with trace-level logging (set ELASTIC_APM_LOG_LEVEL=trace or logLevel: 'trace') and re-run, then you should see a log line something like:

{"log.level":"debug","@timestamp":"2023-04-06T16:29:26.664Z","log":{"logger":"elastic-apm-node"},"remoteConf":{"sanitize_field_names":"password, pass*"},"ecs":{"version":"1.6.0"},"message":"central config received"}

As a workaround, if you need it while I get a fix out, you could remove "sanitize_field_names" from your central configuration in Kibana.