[Bug]: Without the `tls` feature, the Tonic exporter sends unencrypted data to a HTTPS endpoint

[Aaron1011]

What happened?

When using the default Cargo features for the opentelemetry-otlp crate, the tls feature is off by default. Enabling the grpc-tonic feature does not enable TLS.

With the environment variable OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=https://otlp.arize.com/v1 set, and using an exporter built with:

opentelemetry_otlp::SpanExporter::builder()
.with_tonic()
.build()

I observed plain HTTP (non-TLS) traffic being sent to otlp.arize.com (using Wireshark), even though my endpoint url explicitly mentions https Since the remote server is expecting TLS on port 443, the opentelemetry-otlp report tries to parse the server TLS error as plain HTTP, resulting in a confusing error message:

ERROR opentelemetry_sdk:  name="BatchSpanProcessor.ExportError" error="Operation failed: status: Unknown, message: \"transport error\", details: [], metadata: MetadataMap { headers: {} }"

I would expect that trying to using a https endpoint without the tls feature enabled produces an error, rather than silently attempting to use a non-encrypted connection on port 443.

OpenTelemetry API Version (i.e version of opentelemetry crate)

v0.30.0

OpenTelemetry SDK Version (i.e version of opentelemetry_sdk crate)

v0.30.0

What Exporter(s) are you seeing the problem on?

OTLP

Relevant log output

Tip

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[VihasMakwana]

Hello @cijothomas !

I'm a long time contributor to OTeL collector project and am looking to expand my skillset in Rust.

If I understand correctly, the expectation is that https url without tls feature should result in some sort of config validation error?

[scottgerring]

Hello @cijothomas !

I'm a long time contributor to OTeL collector project and am looking to expand my skillset in Rust.

If I understand correctly, the expectation is that https url without tls feature should result in some sort of config validation error?

hey @VihasMakwana yes; this is the case. This should be a straightforward isolated one to pick up if you are interested!