feat: add prometheus metrics to UI

[leafty]

When enabled, the server-side of the UI will produce prometheus metrics.

/deploy renku=leafty/ui-feat-server-side-metrics

Logs when running with metrics enabled:

Starting production server
Setting up metrics
Prometheus exporter is running at http://localhost:9090/metrics
Server is running at http://localhost:3000

Example of custom metrics:

# HELP http_requests_total Total number of HTTP requests.
# TYPE http_requests_total counter
http_requests_total{method="GET",status_code="200"} 8074
http_requests_total{method="GET",status_code="404"} 3

Full example:

# HELP process_cpu_user_seconds_total Total user CPU time spent in seconds.
# TYPE process_cpu_user_seconds_total counter
process_cpu_user_seconds_total 107.08346899999991

# HELP process_cpu_system_seconds_total Total system CPU time spent in seconds.
# TYPE process_cpu_system_seconds_total counter
process_cpu_system_seconds_total 43.819293000000016

# HELP process_cpu_seconds_total Total user and system CPU time spent in seconds.
# TYPE process_cpu_seconds_total counter
process_cpu_seconds_total 150.90276199999983

# 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 1761576810

# HELP process_resident_memory_bytes Resident memory size in bytes.
# TYPE process_resident_memory_bytes gauge
process_resident_memory_bytes 131768320

# HELP process_virtual_memory_bytes Virtual memory size in bytes.
# TYPE process_virtual_memory_bytes gauge
process_virtual_memory_bytes 12111323136

# HELP process_heap_bytes Process heap size in bytes.
# TYPE process_heap_bytes gauge
process_heap_bytes 173371392

# HELP process_open_fds Number of open file descriptors.
# TYPE process_open_fds gauge
process_open_fds 28

# HELP process_max_fds Maximum number of open file descriptors.
# TYPE process_max_fds gauge
process_max_fds 1048576

# HELP nodejs_eventloop_lag_seconds Lag of event loop in seconds.
# TYPE nodejs_eventloop_lag_seconds gauge
nodejs_eventloop_lag_seconds 0.000971473

# HELP nodejs_eventloop_lag_min_seconds The minimum recorded event loop delay.
# TYPE nodejs_eventloop_lag_min_seconds gauge
nodejs_eventloop_lag_min_seconds 0.00909312

# HELP nodejs_eventloop_lag_max_seconds The maximum recorded event loop delay.
# TYPE nodejs_eventloop_lag_max_seconds gauge
nodejs_eventloop_lag_max_seconds 0.013049855

# HELP nodejs_eventloop_lag_mean_seconds The mean of the recorded event loop delays.
# TYPE nodejs_eventloop_lag_mean_seconds gauge
nodejs_eventloop_lag_mean_seconds 0.010096607100401606

# HELP nodejs_eventloop_lag_stddev_seconds The standard deviation of the recorded event loop delays.
# TYPE nodejs_eventloop_lag_stddev_seconds gauge
nodejs_eventloop_lag_stddev_seconds 0.00022545205661100208

# HELP nodejs_eventloop_lag_p50_seconds The 50th percentile of the recorded event loop delays.
# TYPE nodejs_eventloop_lag_p50_seconds gauge
nodejs_eventloop_lag_p50_seconds 0.010084351

# HELP nodejs_eventloop_lag_p90_seconds The 90th percentile of the recorded event loop delays.
# TYPE nodejs_eventloop_lag_p90_seconds gauge
nodejs_eventloop_lag_p90_seconds 0.010117119

# HELP nodejs_eventloop_lag_p99_seconds The 99th percentile of the recorded event loop delays.
# TYPE nodejs_eventloop_lag_p99_seconds gauge
nodejs_eventloop_lag_p99_seconds 0.010903551

# HELP nodejs_active_resources Number of active resources that are currently keeping the event loop alive, grouped by async resource type.
# TYPE nodejs_active_resources gauge
nodejs_active_resources{type="PipeWrap"} 2
nodejs_active_resources{type="TCPServerWrap"} 2
nodejs_active_resources{type="TCPSocketWrap"} 5
nodejs_active_resources{type="Timeout"} 4
nodejs_active_resources{type="Immediate"} 1

# HELP nodejs_active_resources_total Total number of active resources.
# TYPE nodejs_active_resources_total gauge
nodejs_active_resources_total 14

# HELP nodejs_active_handles Number of active libuv handles grouped by handle type. Every handle type is C++ class name.
# TYPE nodejs_active_handles gauge
nodejs_active_handles{type="Socket"} 7
nodejs_active_handles{type="Server"} 2

# HELP nodejs_active_handles_total Total number of active handles.
# TYPE nodejs_active_handles_total gauge
nodejs_active_handles_total 9

# HELP nodejs_active_requests Number of active libuv requests grouped by request type. Every request type is C++ class name.
# TYPE nodejs_active_requests gauge

# HELP nodejs_active_requests_total Total number of active requests.
# TYPE nodejs_active_requests_total gauge
nodejs_active_requests_total 0

# HELP nodejs_heap_size_total_bytes Process heap size from Node.js in bytes.
# TYPE nodejs_heap_size_total_bytes gauge
nodejs_heap_size_total_bytes 33619968

# HELP nodejs_heap_size_used_bytes Process heap size used from Node.js in bytes.
# TYPE nodejs_heap_size_used_bytes gauge
nodejs_heap_size_used_bytes 30107192

# HELP nodejs_external_memory_bytes Node.js external memory size in bytes.
# TYPE nodejs_external_memory_bytes gauge
nodejs_external_memory_bytes 3864752

# HELP nodejs_heap_space_size_total_bytes Process heap space size total from Node.js in bytes.
# TYPE nodejs_heap_space_size_total_bytes gauge
nodejs_heap_space_size_total_bytes{space="read_only"} 0
nodejs_heap_space_size_total_bytes{space="new"} 1048576
nodejs_heap_space_size_total_bytes{space="old"} 19185664
nodejs_heap_space_size_total_bytes{space="code"} 4194304
nodejs_heap_space_size_total_bytes{space="shared"} 0
nodejs_heap_space_size_total_bytes{space="trusted"} 2404352
nodejs_heap_space_size_total_bytes{space="new_large_object"} 0
nodejs_heap_space_size_total_bytes{space="large_object"} 6787072
nodejs_heap_space_size_total_bytes{space="code_large_object"} 0
nodejs_heap_space_size_total_bytes{space="shared_large_object"} 0
nodejs_heap_space_size_total_bytes{space="trusted_large_object"} 0

# HELP nodejs_heap_space_size_used_bytes Process heap space size used from Node.js in bytes.
# TYPE nodejs_heap_space_size_used_bytes gauge
nodejs_heap_space_size_used_bytes{space="read_only"} 0
nodejs_heap_space_size_used_bytes{space="new"} 291376
nodejs_heap_space_size_used_bytes{space="old"} 17862624
nodejs_heap_space_size_used_bytes{space="code"} 3420864
nodejs_heap_space_size_used_bytes{space="shared"} 0
nodejs_heap_space_size_used_bytes{space="trusted"} 1781480
nodejs_heap_space_size_used_bytes{space="new_large_object"} 0
nodejs_heap_space_size_used_bytes{space="large_object"} 6754488
nodejs_heap_space_size_used_bytes{space="code_large_object"} 0
nodejs_heap_space_size_used_bytes{space="shared_large_object"} 0
nodejs_heap_space_size_used_bytes{space="trusted_large_object"} 0

# HELP nodejs_heap_space_size_available_bytes Process heap space size available from Node.js in bytes.
# TYPE nodejs_heap_space_size_available_bytes gauge
nodejs_heap_space_size_available_bytes{space="read_only"} 0
nodejs_heap_space_size_available_bytes{space="new"} 739536
nodejs_heap_space_size_available_bytes{space="old"} 958432
nodejs_heap_space_size_available_bytes{space="code"} 510784
nodejs_heap_space_size_available_bytes{space="shared"} 0
nodejs_heap_space_size_available_bytes{space="trusted"} 578336
nodejs_heap_space_size_available_bytes{space="new_large_object"} 1048576
nodejs_heap_space_size_available_bytes{space="large_object"} 0
nodejs_heap_space_size_available_bytes{space="code_large_object"} 0
nodejs_heap_space_size_available_bytes{space="shared_large_object"} 0
nodejs_heap_space_size_available_bytes{space="trusted_large_object"} 0

# HELP nodejs_version_info Node.js version info.
# TYPE nodejs_version_info gauge
nodejs_version_info{version="v22.21.0",major="22",minor="21",patch="0"} 1

# HELP nodejs_gc_duration_seconds Garbage collection duration by kind, one of major, minor, incremental or weakcb.
# TYPE nodejs_gc_duration_seconds histogram
nodejs_gc_duration_seconds_bucket{le="0.001",kind="incremental"} 46
nodejs_gc_duration_seconds_bucket{le="0.01",kind="incremental"} 56
nodejs_gc_duration_seconds_bucket{le="0.1",kind="incremental"} 76
nodejs_gc_duration_seconds_bucket{le="1",kind="incremental"} 76
nodejs_gc_duration_seconds_bucket{le="2",kind="incremental"} 76
nodejs_gc_duration_seconds_bucket{le="5",kind="incremental"} 76
nodejs_gc_duration_seconds_bucket{le="+Inf",kind="incremental"} 76
nodejs_gc_duration_seconds_sum{kind="incremental"} 0.3731860439744778
nodejs_gc_duration_seconds_count{kind="incremental"} 76
nodejs_gc_duration_seconds_bucket{le="0.001",kind="major"} 0
nodejs_gc_duration_seconds_bucket{le="0.01",kind="major"} 71
nodejs_gc_duration_seconds_bucket{le="0.1",kind="major"} 71
nodejs_gc_duration_seconds_bucket{le="1",kind="major"} 71
nodejs_gc_duration_seconds_bucket{le="2",kind="major"} 71
nodejs_gc_duration_seconds_bucket{le="5",kind="major"} 71
nodejs_gc_duration_seconds_bucket{le="+Inf",kind="major"} 71
nodejs_gc_duration_seconds_sum{kind="major"} 0.15274595399340613
nodejs_gc_duration_seconds_count{kind="major"} 71
nodejs_gc_duration_seconds_bucket{le="0.001",kind="minor"} 4228
nodejs_gc_duration_seconds_bucket{le="0.01",kind="minor"} 4274
nodejs_gc_duration_seconds_bucket{le="0.1",kind="minor"} 4275
nodejs_gc_duration_seconds_bucket{le="1",kind="minor"} 4275
nodejs_gc_duration_seconds_bucket{le="2",kind="minor"} 4275
nodejs_gc_duration_seconds_bucket{le="5",kind="minor"} 4275
nodejs_gc_duration_seconds_bucket{le="+Inf",kind="minor"} 4275
nodejs_gc_duration_seconds_sum{kind="minor"} 2.021798426907503
nodejs_gc_duration_seconds_count{kind="minor"} 4275

# HELP http_request_duration_seconds duration histogram of http responses labeled with: status_code, method
# TYPE http_request_duration_seconds histogram
http_request_duration_seconds_bucket{le="0.003",status_code="200",method="GET"} 7764
http_request_duration_seconds_bucket{le="0.03",status_code="200",method="GET"} 8073
http_request_duration_seconds_bucket{le="0.1",status_code="200",method="GET"} 8073
http_request_duration_seconds_bucket{le="0.3",status_code="200",method="GET"} 8074
http_request_duration_seconds_bucket{le="1.5",status_code="200",method="GET"} 8074
http_request_duration_seconds_bucket{le="10",status_code="200",method="GET"} 8074
http_request_duration_seconds_bucket{le="+Inf",status_code="200",method="GET"} 8074
http_request_duration_seconds_sum{status_code="200",method="GET"} 16.12036073000005
http_request_duration_seconds_count{status_code="200",method="GET"} 8074
http_request_duration_seconds_bucket{le="0.003",status_code="404",method="GET"} 0
http_request_duration_seconds_bucket{le="0.03",status_code="404",method="GET"} 3
http_request_duration_seconds_bucket{le="0.1",status_code="404",method="GET"} 3
http_request_duration_seconds_bucket{le="0.3",status_code="404",method="GET"} 3
http_request_duration_seconds_bucket{le="1.5",status_code="404",method="GET"} 3
http_request_duration_seconds_bucket{le="10",status_code="404",method="GET"} 3
http_request_duration_seconds_bucket{le="+Inf",status_code="404",method="GET"} 3
http_request_duration_seconds_sum{status_code="404",method="GET"} 0.015539727
http_request_duration_seconds_count{status_code="404",method="GET"} 3

# HELP up 1 = up, 0 = not up
# TYPE up gauge
up 1

# HELP http_requests_total Total number of HTTP requests.
# TYPE http_requests_total counter
http_requests_total{method="GET",status_code="200"} 8074
http_requests_total{method="GET",status_code="404"} 3

[RenkuBot]

You can access the deployment of this PR at https://renku-ci-ui-3889.dev.renku.ch