test: validate metrics compatibility with Grafana scrapper

.github/workflows/forest.yml

@@ -83,6 +83,9 @@ jobs:
       - uses: actions/setup-go@v6
         with:
           go-version-file: "go.work"
+      - name: Go tests
+        run: |
+          go test -v ./tools/prometheus_metrics_validator
       - name: Cargo Install
         env:
           # To minimize compile times: https://nnethercote.github.io/perf-book/build-configuration.html#minimizing-compile-times
@@ -155,6 +158,9 @@ jobs:
       - name: Set permissions
         run: |
           chmod +x ~/.cargo/bin/forest*
+      - uses: actions/setup-go@v6
+        with:
+          go-version-file: "go.work"
       - name: Other commands check
         run: ./scripts/tests/calibnet_other_check.sh
         timeout-minutes: ${{ fromJSON(env.SCRIPT_TIMEOUT_MINUTES) }}

go.work

@@ -3,4 +3,5 @@ go 1.25.2
 use (
 	./f3-sidecar
 	./interop-tests/src/tests/go_app
+	./tools/prometheus_metrics_validator
 )

scripts/tests/calibnet_other_check.sh

@@ -79,3 +79,7 @@ if ! [[ "$head_epoch" =~ ^[0-9]+$ ]]; then
 fi
 start_epoch=$(( head_epoch > 900 ? head_epoch - 900 : 0 ))
 $FOREST_CLI_PATH state compute --epoch "$start_epoch" -n 10 -v
+
+echo "Validating metrics"
+wget -O metrics.log http://localhost:6116/metrics
+go run ./tools/prometheus_metrics_validator metrics.log

tools/README.md

@@ -0,0 +1,10 @@
+### Unit tests
+
+- run `go test -v .`
+
+### Validate Forest metrics
+
+```bash
+wget http://localhost:6116/metrics -O metrics.txt
+go run . metrics.txt
+```

tools/prometheus_metrics_validator/.gitignore

@@ -0,0 +1,2 @@
+metrics
+metrics.txt

tools/prometheus_metrics_validator/go.mod

@@ -0,0 +1,24 @@
+module premetheus_metrics_validator/v2
+
+go 1.25.2
+
+require (
+	github.com/prometheus/prometheus v0.306.0
+	github.com/stretchr/testify v1.11.1
+	github.com/urfave/cli/v3 v3.4.1
+)
+
+require (
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853 // indirect
+	github.com/kr/pretty v0.3.1 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/prometheus/common v0.67.1 // indirect
+	go.yaml.in/yaml/v2 v2.4.3 // indirect
+	golang.org/x/text v0.30.0 // indirect
+	google.golang.org/protobuf v1.36.10 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

tools/prometheus_metrics_validator/main.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/prometheus/prometheus/model/labels"
+	"github.com/prometheus/prometheus/model/textparse"
+	"github.com/urfave/cli/v3"
+)
+
+func main() {
+	cmd := &cli.Command{
+		Name:  "prometheus-metrics-validator",
+		Usage: "A tool for validating the compatibility of Prometheus metrics text files with Grafana scrapers.",
+		Arguments: []cli.Argument{
+			&cli.StringArg{
+				Name:      "file",
+				UsageText: "Path to the Prometheus metrics text file",
+			},
+		},
+		Action: func(ctx context.Context, c *cli.Command) error {
+			path := c.StringArg("file")
+			metrics, err := os.ReadFile(path)
+			if err != nil {
+				return err
+			}
+			if err = Validate(metrics); err != nil {
+				fmt.Printf("Validation failed: %v\n", err)
+				os.Exit(1)
+			} else {
+				fmt.Println("Validation passed!")
+			}
+			return nil
+		},
+	}
+	if err := cmd.Run(context.Background(), os.Args); err != nil {
+		panic(err)
+	}
+}
+
+func Validate(metrics []byte) error {
+	p, err := textparse.New(metrics, "text/plain", "", false, false, true, labels.NewSymbolTable())
+	if err != nil {
+		return err
+	}
+	for {
+		if _, err := p.Next(); err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			} else {
+				return err
+			}
+		}
+	}
+	return nil
+}

tools/prometheus_metrics_validator/main_test.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestValidateWithoutEOF(t *testing.T) {
+	metric := []byte(`
+cache_zstd_frame_0_size_bytes 268422051
+zstd_frame_0_len 18022
+zstd_frame_0_cap -1
+`)
+	e := Validate(metric)
+	require.NoError(t, e)
+}
+
+func TestValidateWithEOF(t *testing.T) {
+	metric := []byte(`
+# HELP cache_zstd_frame_0_size_bytes Size of LruCache zstd_frame_0 in bytes
+# TYPE cache_zstd_frame_0_size_bytes gauge
+# UNIT cache_zstd_frame_0_size_bytes bytes
+cache_zstd_frame_0_size_bytes 268422051
+# HELP zstd_frame_0_len Length of LruCache zstd_frame_0
+# TYPE zstd_frame_0_len gauge
+zstd_frame_0_len 18022
+# HELP zstd_frame_0_cap Capacity of LruCache zstd_frame_0
+# TYPE zstd_frame_0_cap gauge
+zstd_frame_0_cap -1
+# EOF
+`)
+	e := Validate(metric)
+	require.NoError(t, e)
+}
+
+func TestValidateWithInvalidCharacters(t *testing.T) {
+	metric := []byte(`
+cache_zstd_frame_0_size_bytes 268422051
+zstd_frame_0_len 18022
+zstd_frame_0_<cap> -1
+`)
+	e := Validate(metric)
+	require.ErrorContains(t, e, "unsupported character")
+}