docs: Add metrics reference

Generated with a dedicated Makefile rule.

Signed-off-by: Anna Kapuscinska <[email protected]>

Makefile

@@ -414,4 +414,16 @@ kind-install-tetragon:
 	./contrib/localdev/install-tetragon.sh --image cilium/tetragon:latest --operator cilium/tetragon-operator:latest
 
 .PHONY: kind-setup
-kind-setup: images kind kind-install-tetragon
+kind-setup: images kind kind-install-tetragon
+
+METRICS_DOCS_PATH := docs/content/en/docs/reference/metrics.md
+
+.PHONY: metrics-docs
+metrics-docs: tetra
+	echo '---' > $(METRICS_DOCS_PATH)
+	echo 'title: "Metrics Reference"' >> $(METRICS_DOCS_PATH)
+	echo 'description: >' >> $(METRICS_DOCS_PATH)
+	echo '  This reference documents Prometheus metrics exposed by Tetragon.' >> $(METRICS_DOCS_PATH)
+	echo 'weight: 4' >> $(METRICS_DOCS_PATH)
+	echo '---' >> $(METRICS_DOCS_PATH)
+	$(CONTAINER_ENGINE) run --rm -v $(PWD):$(PWD) -w $(PWD) $(GO_IMAGE) ./tetra metrics-docs tetragon >> $(METRICS_DOCS_PATH)

docs/content/en/docs/reference/metrics.md

@@ -0,0 +1,201 @@
+---
+title: "Metrics Reference"
+description: >
+  This reference documents Prometheus metrics exposed by Tetragon.
+weight: 4
+---
+<!-- This file is autogenerated via https://github.com/isovalent/metricstool -->
+
+# tetragon Metrics
+
+## `go_gc_duration_seconds`
+
+A summary of the pause duration of garbage collection cycles.
+
+## `go_goroutines`
+
+Number of goroutines that currently exist.
+
+## `go_info`
+
+Information about the Go environment.
+
+| label | values |
+| ----- | ------ |
+| `version` | `go1.22.0` |
+
+## `go_memstats_alloc_bytes`
+
+Number of bytes allocated and still in use.
+
+## `go_memstats_alloc_bytes_total`
+
+Total number of bytes allocated, even if freed.
+
+## `go_memstats_buck_hash_sys_bytes`
+
+Number of bytes used by the profiling bucket hash table.
+
+## `go_memstats_frees_total`
+
+Total number of frees.
+
+## `go_memstats_gc_sys_bytes`
+
+Number of bytes used for garbage collection system metadata.
+
+## `go_memstats_heap_alloc_bytes`
+
+Number of heap bytes allocated and still in use.
+
+## `go_memstats_heap_idle_bytes`
+
+Number of heap bytes waiting to be used.
+
+## `go_memstats_heap_inuse_bytes`
+
+Number of heap bytes that are in use.
+
+## `go_memstats_heap_objects`
+
+Number of allocated objects.
+
+## `go_memstats_heap_released_bytes`
+
+Number of heap bytes released to OS.
+
+## `go_memstats_heap_sys_bytes`
+
+Number of heap bytes obtained from system.
+
+## `go_memstats_last_gc_time_seconds`
+
+Number of seconds since 1970 of last garbage collection.
+
+## `go_memstats_lookups_total`
+
+Total number of pointer lookups.
+
+## `go_memstats_mallocs_total`
+
+Total number of mallocs.
+
+## `go_memstats_mcache_inuse_bytes`
+
+Number of bytes in use by mcache structures.
+
+## `go_memstats_mcache_sys_bytes`
+
+Number of bytes used for mcache structures obtained from system.
+
+## `go_memstats_mspan_inuse_bytes`
+
+Number of bytes in use by mspan structures.
+
+## `go_memstats_mspan_sys_bytes`
+
+Number of bytes used for mspan structures obtained from system.
+
+## `go_memstats_next_gc_bytes`
+
+Number of heap bytes when next garbage collection will take place.
+
+## `go_memstats_other_sys_bytes`
+
+Number of bytes used for other system allocations.
+
+## `go_memstats_stack_inuse_bytes`
+
+Number of bytes in use by the stack allocator.
+
+## `go_memstats_stack_sys_bytes`
+
+Number of bytes obtained from system for stack allocator.
+
+## `go_memstats_sys_bytes`
+
+Number of bytes obtained from system.
+
+## `go_threads`
+
+Number of OS threads created.
+
+## `process_cpu_seconds_total`
+
+Total user and system CPU time spent in seconds.
+
+## `process_max_fds`
+
+Maximum number of open file descriptors.
+
+## `process_open_fds`
+
+Number of open file descriptors.
+
+## `process_resident_memory_bytes`
+
+Resident memory size in bytes.
+
+## `process_start_time_seconds`
+
+Start time of the process since unix epoch in seconds.
+
+## `process_virtual_memory_bytes`
+
+Virtual memory size in bytes.
+
+## `process_virtual_memory_max_bytes`
+
+Maximum amount of virtual memory available in bytes.
+
+## `tetragon_build_info`
+
+Build information about tetragon
+
+| label | values |
+| ----- | ------ |
+| `commit` | `931b70f2c9878ba985ba6b589827bea17da6ec33` |
+| `go_version` | `go1.22.0` |
+| `modified` | `false` |
+| `time ` | `2022-05-13T15:54:45Z` |
+
+## `tetragon_event_cache_accesses_total`
+
+The total number of Tetragon event cache accesses. For internal use only.
+
+## `tetragon_generic_kprobe_merge_ok_total`
+
+The total number of successful attempts to merge a kprobe and kretprobe event.
+
+## `tetragon_generic_kprobe_merge_pushed_total`
+
+The total number of pushed events for later merge.
+
+## `tetragon_notify_overflowed_events_total`
+
+The total number of events dropped because listener buffer was full
+
+## `tetragon_ratelimit_dropped_total`
+
+The total number of rate limit Tetragon drops
+
+## `tetragon_ringbuf_perf_event_errors_total`
+
+The total number of errors when reading the Tetragon ringbuf.
+
+## `tetragon_ringbuf_perf_event_lost_total`
+
+The total number of Tetragon ringbuf perf events lost.
+
+## `tetragon_ringbuf_perf_event_received_total`
+
+The total number of Tetragon ringbuf perf events received.
+
+## `tetragon_ringbuf_queue_lost_total`
+
+The total number of Tetragon events ring buffer queue lost.
+
+## `tetragon_ringbuf_queue_received_total`
+
+The total number of Tetragon events ring buffer queue received.
+