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OpenTelemetry

imgproxy can send request traces to an OpenTelemetry collector. To use this feature, do the following:

  1. Install & configure the OpenTelemetry collector.

  2. Set the IMGPROXY_OPEN_TELEMETRY_ENABLE environment variable to true to enable sending request traces to the collector. Default: false.

  3. (optional) Set the IMGPROXY_OPEN_TELEMETRY_ENABLE_METRICS environment variable to true to enable sending metrics to the collector. Default: false.

  4. (optional) Specify the collector protocol with OTEL_EXPORTER_OTLP_PROTOCOL environment variable.

    tip

    You can specify different protocols for traces and metrics by using the OTEL_EXPORTER_OTLP_TRACES_PROTOCOL and OTEL_EXPORTER_OTLP_METRICS_PROTOCOL environment variables.

    Supported protocols are:

    • grpc (default)
    • http/protobuf (aliases: http, https)

  5. (optional) Specify the collector endpoint with OTEL_EXPORTER_OTLP_ENDPOINT environment variable.

    tip

    Use https:// scheme for secure connections (you may need to configure TLS certificates) and http:// for insecure connections.

    info

    The OTEL_EXPORTER_OTLP_ENDPOINT path should not contain signal-specific paths like /v1/traces or /v1/metrics. The signal-specific paths are added automatically.

    tip

    You can specify different endpoints for traces and metrics by using the OTEL_EXPORTER_OTLP_TRACES_ENDPOINT and OTEL_EXPORTER_OTLP_METRICS_ENDPOINT environment variables. If the http/protobuf protocol is used, these signal-specific endpoints should include the signal-specific paths like /v1/traces or /v1/metrics.

    Defaults are:

    • For the grpc protocol: https://localhost:4317
    • For the http/protobuf protocol: https://localhost:4318

  6. (optional) Set the OTEL_SERVICE_NAME environment variable to be the desired service name. Default: imgproxy.

  7. (optional) Set up TLS certificates.

  8. (optional) Set the IMGPROXY_OPEN_TELEMETRY_TRACE_ID_GENERATOR environment variable to be the desired trace ID generator. Supported values are:

    • xray: (default) Amazon X-Ray compatible trace ID generator
    • random: random trace ID generator

  9. (optional) Use OpenTelemetry configuration environment variables to further customize the behavior.

imgproxy will send the following info to the collector:

  • Response time
  • Queue time
  • Image downloading time
  • Image processing time
  • Errors that occurred while downloading and processing an image

If IMGPROXY_OPEN_TELEMETRY_ENABLE_METRICS is set to true, imgproxy will also send the following metrics to the collector:

  • requests_in_progress: the number of requests currently in progress
  • images_in_progress: the number of images currently in progress
  • buffer_size_bytes: a histogram of buffer sizes (in bytes)
  • buffer_default_size_bytes: calibrated default buffer size (in bytes)
  • buffer_max_size_bytes: calibrated maximum buffer size (in bytes)
  • vips_memory_bytes: libvips memory usage
  • vips_max_memory_bytes: libvips maximum memory usage
  • vips_allocs: the number of active vips allocations
  • Some useful Go metrics like memstats and goroutines count

Configuration​

imgproxy supports the standard general and OTLP exporter-specific environment variables with the following specifics:

  • http/json protocol` is not supported.
  • OTEL_TRACES_EXPORTER and OTEL_METRICS_EXPORTER environment variables are ignored as imgproxy always uses the OTLP exporter.
  • Logs-related environment variables are ignored as imgproxy does not support sending logs to OpenTelemetry.

Also, imgproxy supports the following environment variables:

  • IMGPROXY_OPEN_TELEMETRY_TRACE_ID_GENERATOR: the desired trace ID generator. Supported values are:
    • xray: (default) Amazon X-Ray compatible trace ID generator
    • random: random trace ID generator
  • TLS configuration environment variables.

TLS Configuration​

If your OpenTelemetry collector is secured with TLS, you may need to specify the collector's certificate on the imgproxy side. You can do this by either providing a path to the certificate file or by specifying the certificate itself:

  • IMGPROXY_OPEN_TELEMETRY_SERVER_CERT: OpenTelemetry collector TLS certificate, PEM-encoded (you can replace line breaks with \n). Default: blank

If your collector uses mTLS for mutual authentication, you'll also need to specify the client's certificate/key pair:

  • IMGPROXY_OPEN_TELEMETRY_CLIENT_CERT: OpenTelemetry client TLS certificate, PEM-encoded (you can replace line breaks with \n). Default: blank
  • IMGPROXY_OPEN_TELEMETRY_CLIENT_KEY: OpenTelemetry client TLS key, PEM-encoded (you can replace line breaks with \n). Default: blank
warning

If IMGPROXY_OPEN_TELEMETRY_SERVER_CERT is set and the grpc protocol is used, imgproxy will try to establish a secure connection to the collector even if the collector's endpoint scheme is http://.

Deprecated Environment Variables​

The following environment variables are deprecated and will be removed in the future:

  • IMGPROXY_OPEN_TELEMETRY_ENDPOINT: use OTEL_EXPORTER_OTLP_ENDPOINT instead and explicitly enable OpenTelemetry support with IMGPROXY_OPEN_TELEMETRY_ENABLE environment variable.
    warning

    Unlike IMGPROXY_OPEN_TELEMETRY_ENDPOINT, OTEL_EXPORTER_OTLP_ENDPOINT should contain a URL scheme (http:// or https://).

  • IMGPROXY_OPEN_TELEMETRY_PROTOCOL: use OTEL_EXPORTER_OTLP_PROTOCOL instead.
  • IMGPROXY_OPEN_TELEMETRY_GRPC_INSECURE: use OTEL_EXPORTER_OTLP_ENDPOINT with http:// scheme instead.
  • IMGPROXY_OPEN_TELEMETRY_SERVICE_NAME: use OTEL_SERVICE_NAME instead.
  • IMGPROXY_OPEN_TELEMETRY_PROPAGATORS: use OTEL_PROPAGATORS instead.
  • IMGPROXY_OPEN_TELEMETRY_CONNECTION_TIMEOUT: use OTEL_EXPORTER_OTLP_TIMEOUT instead.
    warning

    Unlike IMGPROXY_OPEN_TELEMETRY_CONNECTION_TIMEOUT, OTEL_EXPORTER_OTLP_TIMEOUT should be specified in milliseconds instead of seconds.