support unix socket for otlp export

[tomatopunk]

Component(s)

No response

Describe the issue you're reporting

Currently, OTLP receivers support Unix socket transport, but OTLP exporters do not. If OTLP export could support Unix sockets, collectors could connect locally instead of over TCP, making data transfer faster and more secure.

This is especially useful in multi-tenant environments, where each tenant has its own collector. With Unix socket support, tenant collectors only need to connect to the local machine’s collector, rather than directly to the central collector.

For example, when the collector and OTLP receiver run on the same host, using a Unix socket reduces resource usage and improves security—important benefits for strict or sensitive environments.

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[bogdandrutu]

Hi @tomatopunk

This should already be supported, on the exporter try use the address like "unix://" + addr.

[tomatopunk]

Hi @tomatopunk

This should already be supported, on the exporter try use the address like "unix://" + addr.

Unfortunately, no supported here, I try to use "unix://+addr", the validation will return an error, since no port is provided, only "http","https","dns" schemes are accepted.

opentelemetry-collector/exporter/otlpexporter/config.go

Lines 31 to 61 in d041e81

	func (c *Config) Validate() error {
	endpoint := c.sanitizedEndpoint()
	if endpoint == "" {
	return errors.New(`requires a non-empty "endpoint"`)
	}
	// Validate that the port is in the address
	_, port, err := net.SplitHostPort(endpoint)
	if err != nil {
	return err
	}
	if _, err := strconv.Atoi(port); err != nil {
	return fmt.Errorf(`invalid port "%s"`, port)
	}
	return nil
	}
	func (c *Config) sanitizedEndpoint() string {
	switch {
	case strings.HasPrefix(c.ClientConfig.Endpoint, "http://"):
	return strings.TrimPrefix(c.ClientConfig.Endpoint, "http://")
	case strings.HasPrefix(c.ClientConfig.Endpoint, "https://"):
	return strings.TrimPrefix(c.ClientConfig.Endpoint, "https://")
	case strings.HasPrefix(c.ClientConfig.Endpoint, "dns://"):
	r := regexp.MustCompile(`^dns:///?`)
	return r.ReplaceAllString(c.ClientConfig.Endpoint, "")
	default:
	return c.ClientConfig.Endpoint
	}
	}

in config:

receivers:
  prometheus:
    config:
      global:
        scrape_interval: 1m
        scrape_timeout: 10s
        scrape_protocols:
        - OpenMetricsText1.0.0
        - OpenMetricsText0.0.1
        - PrometheusText1.0.0
        - PrometheusText0.0.4
        evaluation_interval: 15s
        external_labels:
          monitor: kolla
      scrape_configs:
      - job_name: otel-collector
        honor_timestamps: true
        track_timestamps_staleness: false
        scrape_interval: 30s
        metrics_path: /metrics
        scheme: http
        enable_compression: true
        follow_redirects: true
        enable_http2: true
        static_configs:
        - targets:
          - 0.0.0.0:8888
processors:
  batch:
    send_batch_max_size: 4096
    send_batch_size: 4096
    timeout: 200ms
  memory_limiter:
    check_interval: 5ms
    limit_mib: 1500
    spike_limit_mib: 512
exporters:
  debug: {}
  otlp:
    endpoint: unix:///tmp/otlp.sock
    tls:
      insecure: true
service:
  pipelines:
    metrics:
      exporters:
      - otlp
      receivers:
      - prometheus
  telemetry:
    logs:
      encoding: json
      level: 0
      output_paths:
      - stdout

in collector config

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: /tmp/otlp.sock
        transport: unix

exporters:
  debug: {}
  otlp:
    endpoint: 127.0.0.1:4317
    tls:
      insecure: true


service:
  pipelines:
    traces:
      receivers: [otlp]
      exporters: [debug]
    metrics:
      receivers: [otlp]
      exporters: [debug,otlp]
    logs:
      receivers: [otlp]
      exporters: [debug]

[tomatopunk]

I tested the code - if the port check in validation is removed, socket work and data can be send successfully

[bogdandrutu]

Thank you for testing this, then this is clearly a bug on our side. Do you want to send a PR to fix it? Otherwise I can also do it.

[tomatopunk]

Thank you for testing this, then this is clearly a bug on our side. Do you want to send a PR to fix it? Otherwise I can also do it.

of course, I'd he happy to work on this fix. I'll send a pr shortly for your review