Add simple nextjs request logger plus fix OTEL resource attributes

[ChristopherChudzicki]

What are the relevant tickets?

For https://github.com/mitodl/hq/issues/10971

Description (What does it do?)

This PR:

1. Adds a simple logger for NextJS requests with output like

   {
   "message": "next_request",
   "method": "GET",
   "route": "/search",
   "statusCode": 200,
   "durationMs": 382,
   "traceId": "0e3948306c4b73bd45b1cc4f9aef5366",
   "spanId": "aae162babca4e255",
   "name": "GET /search",
   "version": "test-version"
   }
   

2. makes our OTEL config support OTEL_SERVICE_NAME, OTEL_RESOURCE_ATTRIBUTES, and service.version from NEXT_PUBLIC_VERSION.
   • currently, service.name is hardcoded to 'node' by Sentry, which makes NextJS otel data in Grafana hard to find.

How can this be tested?

1. In your env vars, set

   OTEL_TRACES_SAMPLER_ARG=1.0
   OTEL_SERVICE_NAME=learn-nextjs-local
   OTEL_RESOURCE_ATTRIBUTES=service.namespace=learn-local,other_attr=foo
   OTEL_TRACES_EXPORTER=console
   NEXT_PUBLIC_VERSION=test-version
   NEXT_SERVER_REQUEST_LOGGING=true

2. Start the watch container. You should see an OTEL span in the logs with

   {
     resource: {
       attributes: {
         'service.name': 'learn-local-nextjs', // from OTEL_SERVICE_NAME
         'service.namespace': 'learn-local', // from OTEL_RESOURCE_ATTRIBUTES
         'service.version': 'test-version', // from NEXT_PUBLIC_VERSION
         'telemetry.sdk.language': 'nodejs',
         'telemetry.sdk.name': 'opentelemetry',
         'telemetry.sdk.version': '2.7.0',
         other_attr: 'foo' // from OTEL_RESOURCE_ATTRIBUTES
       }
     }
   }

3. You should also see a line in the logs like (This is from NEXT_SERVER_REQUEST_LOGGING):

   {"message":"next_request","method":"GET","route":"/","statusCode":200,"durationMs":4094,"traceId":"9f7fe6b4d389911acf30630799898d0a","spanId":"04d8e441c1d98b9c","name":"GET, "version": "test-version" /"}

Additional Context

• Sentry does not respect OTEL_SERVICE_NAME or OTEL_RESOURCE_ATTRIBUTES by default.

[github-actions]

OpenAPI Changes

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[Copilot]

Pull request overview

Adds server-side OpenTelemetry helpers to (1) override OTEL resource attributes based on runtime env vars and (2) optionally emit one structured JSON log line per completed Next.js request span, improving trace metadata consistency and enabling lightweight request timing logs.

Changes:

• Added otel-utils helpers to parse OTEL env overrides, apply them to span resources, and format request span logs.
• Wired new span processors into instrumentation-node.ts for resource overrides and optional request logging.
• Documented OTEL exporter endpoint options and request logging env var in env/frontend.env, and added unit tests for the new utilities.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
frontends/main/src/otel-utils.ts	New helpers for parsing OTEL env overrides, applying resource attributes, and building request log entries from server spans.
frontends/main/src/otel-utils.test.ts	Unit tests covering override parsing/applying and request log entry creation.
frontends/main/src/instrumentation-node.ts	Registers new span processors (resource override + optional request logging) alongside existing OTLP/console exporters.
env/frontend.env	Updates local/prod OTEL endpoint documentation and adds NEXT_SERVER_REQUEST_LOGGING documentation.

[ChristopherChudzicki]

This seems likely to be fixed soon, see

• fix(opentelemetry): Respect OTEL_SERVICE_NAME, OTEL_RESOURCE_ATTRIBUTES getsentry/sentry-javascript#20509

though i'd still like to have the data before their fix is merged/released.

[sentry]

Bug: The async function detectResourceOverrides may be called without await, which could lead to a race condition.
_{Severity: MEDIUM}

Suggested Fix

Review all call sites of the detectResourceOverrides function and ensure that the returned Promise is properly handled, typically by adding the await keyword before the function call.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: frontends/main/src/otel-utils.ts#L41

Potential issue: The function `detectResourceOverrides` is declared as `async`, meaning
it returns a Promise. If a caller does not use the `await` keyword when invoking this
function, the program will not wait for the promise to resolve. This can lead to a race
condition where code that depends on the completion of `detectResourceOverrides`
executes prematurely. Given the function's name, this could result in improperly
configured OpenTelemetry resources, affecting observability and monitoring.

[ChristopherChudzicki]

The function is not async. It returns a plain object, Record<string, DetectedResourceAttributeValue>