OTEL env var not taken into account

[dhiaayachi]

Expected Behavior

Hello :)

Sending trace to a jaeger instance by specifying OTEL* env variables as it's said in the docs.

$ docker inspect temporal-server | grep OTEL
                "OTEL_EXPORTER_OTLP_INSECURE=true",
                "OTEL_LOG_LEVEL=debug",
                "OTEL_TRACES_EXPORTER=otlp",
                "OTEL_EXPORTER_OTLP_TRACES_PROTOCOL=grpc",
                "OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=jaeger:4317",
                "OTEL_EXPORTER_OTLP_TRACES_INSECURE=true",

Actual Behavior

OTEL_* env variables aren't taken into account.

The only way I managed to make this work is to use this config:

otel:
  exporters:
    - kind:
        signal: traces
        model: otlp
        protocol: grpc
      spec:
        connection:
          insecure: true
          endpoint: jaeger:4317

Steps to Reproduce the Problem

1. Start jaeger using https://github.com/temporalio/temporal/blob/master/develop/docker-compose/docker-compose.jaeger.yml
2. Start a temporal-server with the following env variable

            OTEL_EXPORTER_OTLP_TRACES_ENDPOINT: "jaeger:4317"
            OTEL_EXPORTER_OTLP_TRACES_PROTOCOL: grpc
            OTEL_EXPORTER_OTLP_TRACES_INSECURE: "true"
            OTEL_EXPORTER_OTLP_INSECURE: "true"
            OTEL_EXPORTER_OTLP_SPAN_INSECURE: "true"

3. Open the jaeger UI: there is now trace

Specifications

• Version: Temporal 1.18.1
• Platform: Docker (running on Debian 10)