Metrics explained?

Recently integrated cloudflared into my PiHole solution for DoH. I really dig the metrics feature and I'm presently attempting to build dashboards for the data to augment monitoring of my DNS solution. I've searched high and low and I cannot find the metrics documented anywhere. I've resorted to guessing, but I know I'm getting some things wrong. I apologize if this is the improper forum for this question, and I'd be happy to post this question somewhere more appropriate if necessary!

Great feedback. We'll get this into developer docs.

cc: @abracchi-tw

I second this. These are the endpoints available: https://stackoverflow.com/questions/43304363/simple-server-side-flask-session-variable

If you go to http//localhost:<metrics_endpoint>/metrics, you'll get explanation of the response like so:

neil@cloudflare-server:~$ curl localhost:5432/metrics
# HELP build_info Build and version information
# TYPE build_info gauge
build_info{goversion="go1.17.5",revision="2022-02-18-1107 UTC",type="",version="2022.2.1"} 1
# HELP cloudflared_tunnel_active_streams Number of active streams created by all muxers.
# TYPE cloudflared_tunnel_active_streams gauge
cloudflared_tunnel_active_streams 0
# HELP cloudflared_tunnel_concurrent_requests_per_tunnel Concurrent requests proxied through each tunnel
# TYPE cloudflared_tunnel_concurrent_requests_per_tunnel gauge
cloudflared_tunnel_concurrent_requests_per_tunnel 0
# HELP cloudflared_tunnel_ha_connections Number of active ha connections
# TYPE cloudflared_tunnel_ha_connections gauge
cloudflared_tunnel_ha_connections 4
# HELP cloudflared_tunnel_request_errors Count of error proxying to origin
# TYPE cloudflared_tunnel_request_errors counter
cloudflared_tunnel_request_errors 0
# HELP cloudflared_tunnel_response_by_code Count of responses by HTTP status code
# TYPE cloudflared_tunnel_response_by_code counter
cloudflared_tunnel_response_by_code{status_code="200"} 267
cloudflared_tunnel_response_by_code{status_code="304"} 1
cloudflared_tunnel_response_by_code{status_code="404"} 18
# HELP cloudflared_tunnel_server_locations Where each tunnel is connected to. 1 means current location, 0 means previous locations.
# TYPE cloudflared_tunnel_server_locations gauge
cloudflared_tunnel_server_locations{connection_id="0",location="SJC"} 1
cloudflared_tunnel_server_locations{connection_id="1",location="LAX"} 1
cloudflared_tunnel_server_locations{connection_id="2",location="SJC"} 1
cloudflared_tunnel_server_locations{connection_id="3",location="LAX"} 1
# HELP cloudflared_tunnel_timer_retries Unacknowledged heart beats count
# TYPE cloudflared_tunnel_timer_retries gauge
cloudflared_tunnel_timer_retries 0
# HELP cloudflared_tunnel_total_requests Amount of requests proxied through all the tunnels
# TYPE cloudflared_tunnel_total_requests counter
cloudflared_tunnel_total_requests 286
# HELP cloudflared_tunnel_tunnel_authenticate_success Count of successful tunnel authenticate
# TYPE cloudflared_tunnel_tunnel_authenticate_success counter
cloudflared_tunnel_tunnel_authenticate_success 0
# HELP cloudflared_tunnel_tunnel_register_success Count of successful tunnel registrations
# TYPE cloudflared_tunnel_tunnel_register_success counter
cloudflared_tunnel_tunnel_register_success{rpcName="registerConnection"} 4
# HELP coredns_panics_total A metrics that counts the number of panics.
# TYPE coredns_panics_total counter
coredns_panics_total 0
# HELP go_gc_duration_seconds A summary of the pause duration of garbage collection cycles.
# TYPE go_gc_duration_seconds summary
go_gc_duration_seconds{quantile="0"} 2.8802e-05
go_gc_duration_seconds{quantile="0.25"} 0.000133578
go_gc_duration_seconds{quantile="0.5"} 0.000187205
go_gc_duration_seconds{quantile="0.75"} 0.000238817
go_gc_duration_seconds{quantile="1"} 0.001243708
go_gc_duration_seconds_sum 0.117248326
go_gc_duration_seconds_count 516
# HELP go_goroutines Number of goroutines that currently exist.
# TYPE go_goroutines gauge
go_goroutines 51
# HELP go_info Information about the Go environment.
# TYPE go_info gauge
go_info{version="go1.17.5"} 1
# HELP go_memstats_alloc_bytes Number of bytes allocated and still in use.
# TYPE go_memstats_alloc_bytes gauge
go_memstats_alloc_bytes 2.722912e+06
# HELP go_memstats_alloc_bytes_total Total number of bytes allocated, even if freed.
# TYPE go_memstats_alloc_bytes_total counter
go_memstats_alloc_bytes_total 8.5092392e+07
# HELP go_memstats_buck_hash_sys_bytes Number of bytes used by the profiling bucket hash table.
# TYPE go_memstats_buck_hash_sys_bytes gauge
go_memstats_buck_hash_sys_bytes 1.464278e+06
# HELP go_memstats_frees_total Total number of frees.
# TYPE go_memstats_frees_total counter
go_memstats_frees_total 700420
# HELP go_memstats_gc_cpu_fraction The fraction of this program's available CPU time used by the GC since the program started.
# TYPE go_memstats_gc_cpu_fraction gauge
go_memstats_gc_cpu_fraction 4.8639760342857114e-06
# HELP go_memstats_gc_sys_bytes Number of bytes used for garbage collection system metadata.
# TYPE go_memstats_gc_sys_bytes gauge
go_memstats_gc_sys_bytes 5.502848e+06
# HELP go_memstats_heap_alloc_bytes Number of heap bytes allocated and still in use.
# TYPE go_memstats_heap_alloc_bytes gauge
go_memstats_heap_alloc_bytes 2.722912e+06
# HELP go_memstats_heap_idle_bytes Number of heap bytes waiting to be used.
# TYPE go_memstats_heap_idle_bytes gauge
go_memstats_heap_idle_bytes 1.0706944e+07
# HELP go_memstats_heap_inuse_bytes Number of heap bytes that are in use.
# TYPE go_memstats_heap_inuse_bytes gauge
go_memstats_heap_inuse_bytes 4.95616e+06
# HELP go_memstats_heap_objects Number of allocated objects.
# TYPE go_memstats_heap_objects gauge
go_memstats_heap_objects 17090
# HELP go_memstats_heap_released_bytes Number of heap bytes released to OS.
# TYPE go_memstats_heap_released_bytes gauge
go_memstats_heap_released_bytes 1.0584064e+07
# HELP go_memstats_heap_sys_bytes Number of heap bytes obtained from system.
# TYPE go_memstats_heap_sys_bytes gauge
go_memstats_heap_sys_bytes 1.5663104e+07
# HELP go_memstats_last_gc_time_seconds Number of seconds since 1970 of last garbage collection.
# TYPE go_memstats_last_gc_time_seconds gauge
go_memstats_last_gc_time_seconds 1.64538585455484e+09
# HELP go_memstats_lookups_total Total number of pointer lookups.
# TYPE go_memstats_lookups_total counter
go_memstats_lookups_total 0
# HELP go_memstats_mallocs_total Total number of mallocs.
# TYPE go_memstats_mallocs_total counter
go_memstats_mallocs_total 717510
# HELP go_memstats_mcache_inuse_bytes Number of bytes in use by mcache structures.
# TYPE go_memstats_mcache_inuse_bytes gauge
go_memstats_mcache_inuse_bytes 9600
# HELP go_memstats_mcache_sys_bytes Number of bytes used for mcache structures obtained from system.
# TYPE go_memstats_mcache_sys_bytes gauge
go_memstats_mcache_sys_bytes 16384
# HELP go_memstats_mspan_inuse_bytes Number of bytes in use by mspan structures.
# TYPE go_memstats_mspan_inuse_bytes gauge
go_memstats_mspan_inuse_bytes 160208
# HELP go_memstats_mspan_sys_bytes Number of bytes used for mspan structures obtained from system.
# TYPE go_memstats_mspan_sys_bytes gauge
go_memstats_mspan_sys_bytes 180224
# HELP go_memstats_next_gc_bytes Number of heap bytes when next garbage collection will take place.
# TYPE go_memstats_next_gc_bytes gauge
go_memstats_next_gc_bytes 5.005568e+06
# HELP go_memstats_other_sys_bytes Number of bytes used for other system allocations.
# TYPE go_memstats_other_sys_bytes gauge
go_memstats_other_sys_bytes 1.89765e+06
# HELP go_memstats_stack_inuse_bytes Number of bytes in use by the stack allocator.
# TYPE go_memstats_stack_inuse_bytes gauge
go_memstats_stack_inuse_bytes 1.114112e+06
# HELP go_memstats_stack_sys_bytes Number of bytes obtained from system for stack allocator.
# TYPE go_memstats_stack_sys_bytes gauge
go_memstats_stack_sys_bytes 1.114112e+06
# HELP go_memstats_sys_bytes Number of bytes obtained from system.
# TYPE go_memstats_sys_bytes gauge
go_memstats_sys_bytes 2.58386e+07
# HELP go_threads Number of OS threads created.
# TYPE go_threads gauge
go_threads 14
# HELP process_cpu_seconds_total Total user and system CPU time spent in seconds.
# TYPE process_cpu_seconds_total counter
process_cpu_seconds_total 25.81
# HELP process_max_fds Maximum number of open file descriptors.
# TYPE process_max_fds gauge
process_max_fds 1024
# HELP process_open_fds Number of open file descriptors.
# TYPE process_open_fds gauge
process_open_fds 14
# HELP process_resident_memory_bytes Resident memory size in bytes.
# TYPE process_resident_memory_bytes gauge
process_resident_memory_bytes 3.538944e+07
# HELP process_start_time_seconds Start time of the process since unix epoch in seconds.
# TYPE process_start_time_seconds gauge
process_start_time_seconds 1.64532509936e+09
# HELP process_virtual_memory_bytes Virtual memory size in bytes.
# TYPE process_virtual_memory_bytes gauge
process_virtual_memory_bytes 7.46213376e+08
# HELP process_virtual_memory_max_bytes Maximum amount of virtual memory available in bytes.
# TYPE process_virtual_memory_max_bytes gauge
process_virtual_memory_max_bytes 1.8446744073709552e+19
# HELP promhttp_metric_handler_requests_in_flight Current number of scrapes being served.
# TYPE promhttp_metric_handler_requests_in_flight gauge
promhttp_metric_handler_requests_in_flight 1
# HELP promhttp_metric_handler_requests_total Total number of scrapes by HTTP status code.
# TYPE promhttp_metric_handler_requests_total counter
promhttp_metric_handler_requests_total{code="200"} 0
promhttp_metric_handler_requests_total{code="500"} 0
promhttp_metric_handler_requests_total{code="503"} 0