core modules imported with require('node:...') are not instrumented #2816
Description
Instrumentation for the following does not work because node:http is required instead of http.
// node-prefixed-core-modules.js
require('./').start() // elastic-apm-node
const http = require('node:http')
const server = http.createServer((req, res) => {
req.resume()
res.statusCode = 200
res.end('pong')
})
server.listen(3000, () => {
http.get('http://localhost:3000', res => {
console.log('CLIENT: res.headers:', res.headers)
res.resume()
res.on('end', () => {
console.log('CLIENT: res "end"')
server.close()
})
})
})Support for node:-prefixed imports to explicitly mean core modules was added in node v16.0.0 (and maybe in v14.8.0?). See nodejs/node#37246
With require-in-the-middle debug logging:
% DEBUG=require-in-the-middle node foo.js
require-in-the-middle registering require hook +0ms
require-in-the-middle processing non-core module require('./system-cpu'): /Users/trentm/el/apm-agent-nodejs/lib/metrics/platforms/generic/system-cpu.js +3ms
require-in-the-middle processing core module require('os'): os +1ms
require-in-the-middle ignoring core module not on whitelist: os +0ms
require-in-the-middle could not parse filename: /Users/trentm/el/apm-agent-nodejs/lib/metrics/platforms/generic/system-cpu.js +1ms
require-in-the-middle processing non-core module require('node:http'): node:http +3ms
require-in-the-middle could not parse filename: node:http +0ms
CLIENT: res.headers: {
date: 'Fri, 08 Jul 2022 21:53:22 GMT',
connection: 'close',
'content-length': '4'
}
CLIENT: res "end"
The issue is that require-in-the-middle's isCore fails:
const filename = Module._resolveFilename(id, this) // filename = 'node:http'
const core = isCore(filename) // core = falseWe'll need to update require-in-the-middle to fix this. We should watch out for not separately wrapping require('http') and require('node:http'), so perhaps a good answer would be to normalize the filename. E.g. a first naive stab could just drop the leading node: if any. ... Yup, making this change in require-in-the-middle/index.js works:
let filename = Module._resolveFilename(id, this)
if (filename.startsWith('node:')) {
filename = filename.slice(5)
}
const core = isCore(filename)