imgproxy can collect its metrics for Prometheus. To use this feature, do the following:
IMGPROXY_PROMETHEUS_BIND environment variable. Note that you can't bind the main server and Prometheus to the same port;imgproxy will collect the following metrics:
requests_total - a counter of the total number of HTTP requests imgproxy processed;errors_total - a counter of the occurred errors separated by type (timeout, downloading, processing);request_duration_seconds - a histogram of the response latency (seconds);download_duration_seconds - a histogram of the source image downloading latency (seconds);processing_duration_seconds - a histogram of the image processing latency (seconds);buffer_size_bytes - a histogram of the download/gzip buffers sizes (bytes);buffer_default_size_bytes - calibrated default buffer size (bytes);buffer_max_size_bytes - calibrated maximum buffer size (bytes);vips_memory_bytes - libvips memory usage;vips_max_memory_bytes - libvips maximum memory usage;vips_allocs - the number of active vips allocations;