Add YAML support for default and custom metrics definition (#302)

Introduce YAML support for exporter metrics files

Author: Supporterino

collector/collector.go

@@ -20,7 +20,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/BurntSushi/toml"
 	_ "github.com/godror/godror"
 	"github.com/prometheus/client_golang/prometheus"
 )
@@ -59,7 +58,7 @@ func NewExporter(logger *slog.Logger, m *MetricsConfiguration) *Exporter {
 	// set to a blank value.
 	for _, dbconfig := range m.Databases {
 		for label, _ := range dbconfig.Labels {
-			if (!slices.Contains(allConstLabels, label)) {
+			if !slices.Contains(allConstLabels, label) {
 				allConstLabels = append(allConstLabels, label)
 			}
 		}
@@ -400,12 +399,14 @@ func (e *Exporter) reloadMetrics() {
 	if len(e.CustomMetricsFiles()) > 0 {
 		for _, _customMetrics := range e.CustomMetricsFiles() {
 			metrics := &Metrics{}
-			if _, err := toml.DecodeFile(_customMetrics, metrics); err != nil {
+
+			if err := loadMetricsConfig(_customMetrics, metrics); err != nil {
 				e.logger.Error("failed to load custom metrics", "error", err)
 				panic(errors.New("Error while loading " + _customMetrics))
 			} else {
 				e.logger.Info("Successfully loaded custom metrics from " + _customMetrics)
 			}
+
 			e.metricsToScrape.Metric = append(e.metricsToScrape.Metric, metrics.Metric...)
 		}
 	} else {

collector/data_loader.go

@@ -0,0 +1,44 @@
+// Copyright (c) 2025, Oracle and/or its affiliates.
+// Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl.
+
+package collector
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/BurntSushi/toml"
+	"gopkg.in/yaml.v2"
+)
+
+func loadYamlMetricsConfig(_metricsFileName string, metrics *Metrics) error {
+	yamlBytes, err := os.ReadFile(_metricsFileName)
+	if err != nil {
+		return fmt.Errorf("cannot read the metrics config %s: %w", _metricsFileName, err)
+	}
+	if err := yaml.Unmarshal(yamlBytes, metrics); err != nil {
+		return fmt.Errorf("cannot unmarshal the metrics config %s: %w", _metricsFileName, err)
+	}
+	return nil
+}
+
+func loadTomlMetricsConfig(_customMetrics string, metrics *Metrics) error {
+	if _, err := toml.DecodeFile(_customMetrics, metrics); err != nil {
+		return fmt.Errorf("cannot read the metrics config %s: %w", _customMetrics, err)
+	}
+	return nil
+}
+
+func loadMetricsConfig(_customMetrics string, metrics *Metrics) error {
+	if strings.HasSuffix(_customMetrics, "toml") {
+		if err := loadTomlMetricsConfig(_customMetrics, metrics); err != nil {
+			return fmt.Errorf("cannot load toml based metrics: %w", err)
+		}
+	} else {
+		if err := loadYamlMetricsConfig(_customMetrics, metrics); err != nil {
+			return fmt.Errorf("cannot load yaml based metrics: %w", err)
+		}
+	}
+	return nil
+}

collector/default_metrics.go

@@ -20,7 +20,7 @@ var defaultMetricsToml string
 func (e *Exporter) DefaultMetrics() Metrics {
 	var metricsToScrape Metrics
 	if e.Metrics.Default != "" {
-		if _, err := toml.DecodeFile(filepath.Clean(e.Metrics.Default), &metricsToScrape); err != nil {
+		if err := loadMetricsConfig(filepath.Clean(e.Metrics.Default), &metricsToScrape); err != nil {
 			e.logger.Error(fmt.Sprintf("there was an issue while loading specified default metrics file at: "+e.Metrics.Default+", proceeding to run with default metrics."),
 				"error", err)
 		}

go.mod

@@ -31,7 +31,6 @@ require (
 	github.com/golang-jwt/jwt/v5 v5.2.2 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/jpillora/backoff v1.0.0 // indirect
-	github.com/klauspost/compress v1.18.0 // indirect
 	github.com/kylelemons/godebug v1.1.0 // indirect
 	github.com/mdlayher/socket v0.4.1 // indirect
 	github.com/mdlayher/vsock v1.2.1 // indirect