certificate is misleading in environment variables

[xman1979]

There are essentially two type of "certificate" in TLS context,

• verifier, also called CA (certificate authority), used to verify server certificate, so we can trust the server
• client certificate, used like a credential so the server can trust and authenticate the client

However, I don't think it is being clearly called out, e.g:

opentelemetry-python/opentelemetry-sdk/src/opentelemetry/sdk/environment_variables.py

Line 521 in d213e02

The :envvar:`OTEL_EXPORTER_OTLP_LOGS_CERTIFICATE` stores the path to the certificate file for

It sounds like the client certificate, but used as verifier here:

opentelemetry-python/exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/_log_exporter/__init__.py

Line 119 in d213e02

verify=self._certificate_file,

Can we make it clear and rename the environment if possible, so it won't be so confusing?

E.g:

OTEL_EXPORTER_OTLP_LOGS_CA_FILE
: path to a CA bundle (.pem)

OTEL_EXPORTER_OTLP_LOGS_CLIENT_CERT_FILE
: ssl client cert file (.pem).

[xrmx]

The variables names are not python specific, see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/protocol/exporter.md