Component(s)

exporter/clickhouse

What happened?

Description

#22805 introduced TLS parameters for the ClickHouse exporter. It seems that these parameters are only taken into account if cert_file or key_file are set (so client-side TLS). However, the other configuration options, such as ca_file, would also be useful for server-side TLS.

I think this due to this condition in exporter/clickhouseexporter/config.go:

if cfg.TLS.CertFile != "" || cfg.TLS.KeyFile != ""

Steps to Reproduce

I stumbled across this issue when configuring ClickHouse to do server-side TLS. I configured the exporter according to the documentation. In particular, I wanted to use these fields:

exporters:
  clickhouse:
    endpoint: . . .
    tls:
      insecure: false
      insecure_skip_verify: false
      ca_file: CAroot.crt
      server_name_override: my-server

Expected Result

The TLS configuration is taken into account.

Actual Result

The TLS configuration was ignored until I added the fields cert_file and key_file, even though the ClickHouse server does not expect client-side TLS for the configured user. Once I added these fields, the exporter was able to send data to ClickHouse.

Collector version

v0.138.0

Environment information

OpenTelemetry Collector configuration

receivers:
  otlp/grpc:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317
processors:
exporters:
  clickhouse:
    endpoint: tcp://localhost:35979
    username: my-user
    password: my-password
    database: my-db
    tls:
      ca_file: /ca.pem
      server_name_override: my-server
      insecure: false
      insecure_skip_verify: false
      cert_file: /cert.pem
      key_file: /cert.pem
    connection_params:
      secure: 'true'
    create_schema: false
extensions: {}
service:
  pipelines:
    metrics/otlp/grpc-clickhouse:
      receivers:
      - otlp/grpc
      processors:
      exporters:
      - clickhouse

Log output

Additional context

No response

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