tetra: Add metrics-docs command

This command utilizes github.com/isovalent/metricstool/pkg/metricsmd to
generate a metrics reference.

Signed-off-by: Anna Kapuscinska <anna@isovalent.com>

cmd/tetra/commands_linux.go

@@ -6,6 +6,7 @@ package main
 import (
 	"github.com/cilium/tetragon/cmd/tetra/bugtool"
 	"github.com/cilium/tetragon/cmd/tetra/dump"
+	"github.com/cilium/tetragon/cmd/tetra/metrics"
 	"github.com/cilium/tetragon/cmd/tetra/policyfilter"
 	"github.com/cilium/tetragon/cmd/tetra/probe"
 	"github.com/cilium/tetragon/cmd/tetra/tracingpolicy"
@@ -19,4 +20,5 @@ func addCommands(rootCmd *cobra.Command) {
 	rootCmd.AddCommand(dump.New())
 	rootCmd.AddCommand(policyfilter.New())
 	rootCmd.AddCommand(probe.New())
+	rootCmd.AddCommand(metrics.New())
 }

cmd/tetra/metrics/print.go

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Authors of Tetragon
+
+package metrics
+
+import (
+	"log/slog"
+
+	"github.com/isovalent/metricstool/pkg/metricsmd"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/spf13/cobra"
+
+	"github.com/cilium/tetragon/pkg/metrics/metricsconfig"
+)
+
+func New() *cobra.Command {
+	targets := map[string]string{
+		"tetragon": "Tetragon",
+	}
+
+	overrides := []metricsmd.LabelOverrides{
+		// Theses metrics takes VCS info into account supplied at build
+		// time, which changes every build, so override those.
+		{
+			Metric: "go_info",
+			Overrides: []metricsmd.LabelValues{
+				{
+					Label:  "version",
+					Values: []string{"go1.22.0"},
+				},
+			},
+		},
+		{
+			Metric: "tetragon_build_info",
+			Overrides: []metricsmd.LabelValues{
+				{
+					Label:  "commit",
+					Values: []string{"931b70f2c9878ba985ba6b589827bea17da6ec33"},
+				},
+				{
+					Label:  "go_version",
+					Values: []string{"go1.22.0"},
+				},
+				{
+					Label:  "modified",
+					Values: []string{"false"},
+				},
+				{
+					Label:  "time",
+					Values: []string{"2022-05-13T15:54:45Z"},
+				},
+			},
+		},
+	}
+
+	return metricsmd.NewCmd(nil, nil, map[string]string{}, targets, overrides, initMetrics)
+}
+
+func initMetrics(_ string, reg *prometheus.Registry, _ *slog.Logger) error {
+	metricsconfig.InitAllMetrics(reg)
+	return nil
+}

go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.0
 	github.com/hashicorp/golang-lru/v2 v2.0.7
 	github.com/iancoleman/strcase v0.3.0
+	github.com/isovalent/metricstool v0.0.0-20240220124724-285815580016
 	github.com/jpillora/longestcommon v0.0.0-20161227235612-adb9d91ee629
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/mennanov/fieldmask-utils v1.1.0

go.sum

@@ -335,6 +335,8 @@ github.com/imdario/mergo v0.3.16 h1:wwQJbIsHYGMUyLSPrEq1CT16AhnhNJQ51+4fdHUnCl4=
 github.com/imdario/mergo v0.3.16/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/isovalent/metricstool v0.0.0-20240220124724-285815580016 h1:8kTfM4TIcCeKUfD0ct45SHLUgIqBB391be1HuyjaKVc=
+github.com/isovalent/metricstool v0.0.0-20240220124724-285815580016/go.mod h1:ol80lPphlGYFS16mc54bPVudTT8GkIaHwRMiUuya0sY=
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOlocH6Fxy8MmwDt+yVQYULKfN0RoTN8A=
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99/go.mod h1:1lJo3i6rXxKeerYnT8Nvf0QmHCRC1n8sfWVwXF2Frvo=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=