Code to support environment variables for exporter does not meet spec.

[longility]

What did you do?

import { CollectorTraceExporter } from "@opentelemetry/exporter-collector-proto";

const traceExporter = new CollectorTraceExporter();

I added an env var like so OTEL_EXPORTER_OTLP_ENDPOINT=http://example.com

What did you expect to see?

For the exporter collector to send successfully and internally, automatically append v1/traces and v1/metrics.

What did you see instead?

However, it did not append like the spec says it should if I understand it correctly to where I had to add an env var like so OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://example.com/v1/traces to get it working.

code reference: https://github.com/open-telemetry/opentelemetry-js/blob/main/packages/opentelemetry-exporter-collector/src/platform/node/CollectorTraceExporter.ts#L52:L58

    return typeof config.url === 'string'
      ? config.url
      : getEnv().OTEL_EXPORTER_OTLP_TRACES_ENDPOINT.length > 0
      ? getEnv().OTEL_EXPORTER_OTLP_TRACES_ENDPOINT
      : getEnv().OTEL_EXPORTER_OTLP_ENDPOINT.length > 0
      ? getEnv().OTEL_EXPORTER_OTLP_ENDPOINT
      : DEFAULT_COLLECTOR_URL;

Additional context

Specification reference: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/protocol/exporter.md

Target to which the exporter is going to send spans or metrics. The endpoint MUST be a valid URL with scheme (http or https) and host, and MAY contain a port and path. A scheme of https indicates a secure connection. When using OTEL_EXPORTER_OTLP_ENDPOINT, exporters SHOULD follow the collector convention of appending the version and signal to the path (e.g. v1/traces or v1/metrics), if not present already. The per-signal endpoint configuration options take precedence and can be used to override this behavior. See the OTLP Specification for more details.

[longility]

If this is a bug, I can submit PR to fixing the issue.

[dyladan]

The code you linked seems to support the env var. If you're saying it doesn't work then it is indeed a bug.

[longility]

@dyladan Sorry, maybe I wasn't clear. It supports the env var, but it doesn't follow the specification.

exporters SHOULD follow the collector convention of appending the version and signal to the path (e.g. v1/traces or v1/metrics), if not present already.

so I would think that if I do OTEL_EXPORTER_OTLP_ENDPOINT=http://example.com, then internally, it should append v1/traces when doing tracing and v1/metrics when doing metrics. However, it does not. I was thrown off as it wasn't working until I realized it wasn't appending v1/traces when I was trying to get tracing working going somewhere else.

[dyladan]

ah I understand. yes I would like to see this fixed