imgproxy/docs/open_telemetry.md

OpenTelemetry

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

1. Install & configure the OpenTelemetry collector.
2. Specify the collector endpoint (host:port) with IMGPROXY_OPEN_TELEMETRY_ENDPOINT and the collector protocol with IMGPROXY_OPEN_TELEMETRY_PROTOCOL. Supported protocols are:
   • grpc (default)
   • https
   • http.
3. (optional) Set the IMGPROXY_OPEN_TELEMETRY_SERVICE_NAME environment variable to be the desired service name.
4. (optional) Set the IMGPROXY_OPEN_TELEMETRY_PROPAGATORS environment variable to be the desired list of text map propagators. Supported propagators are:
   • tracecontext: W3C Trace Context
   • baggage: W3C Baggage
   • b3: B3 Single
   • b3multi: B3 Multi
   • jaeger: Jaeger
   • xray: AWS X-Ray
   • ottrace: OT Trace
5. (optional) Set up TLS certificates.
6. (optional) Set IMGPROXY_OPEN_TELEMETRY_ENABLE_METRICS to true to enable sending metrics via OpenTelemetry Metrics API.

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
• vips_memory_bytes: libvips memory usage
• vips_max_memory_bytes: libvips maximum memory usage
• vips_allocs: the number of active vips allocations

TLS Configuration

If your OpenTelemetry collector is secured with TLS, you may need to specify the collector's certificate on the imgproxy side:

• IMGPROXY_OPEN_TELEMETRY_SERVER_CERT: OpenTelemetry collector TLS certificate, PEM-encoded. 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. Default: blank
• IMGPROXY_OPEN_TELEMETRY_CLIENT_KEY: OpenTelemetry client TLS key, PEM-encoded. Default: blank