give the possibility to define a set of a rule collectors instead of …

…a single one

Signed-off-by: Augustin Husson <[email protected]>

README.md

@@ -92,17 +92,19 @@ metric_collector:
 
 This collector gets the Prometheus Rules Group using the HTTP API. Then it extracts the metric used in the alert rule or in the recording rule.
 
+You define a set of rule collectors as we are assuming rules can com from various Prometheus / Thanos rulers.
+
 #### Configuration
 
 See the doc for the complete configuration [here](./docs/configuration.md#rules_collector-config)
 
 Example: 
 
 ```yaml
-rules_collector:
-  enable: true
-  prometheus_client:
-    url: "https://prometheus.demo.do.prometheus.io"
+rules_collectors:
+  - enable: true
+    prometheus_client:
+      url: "https://prometheus.demo.do.prometheus.io"
 ```
 
 ### Perses Collector

config/config.go

@@ -3,10 +3,10 @@ package config
 import "github.com/perses/common/config"
 
 type Config struct {
-	MetricCollector  MetricCollector  `yaml:"metric_collector,omitempty"`
-	RulesCollector   RulesCollector   `yaml:"rules_collector,omitempty"`
-	PersesCollector  PersesCollector  `yaml:"perses_collector,omitempty"`
-	GrafanaCollector GrafanaCollector `yaml:"grafana_collector,omitempty"`
+	MetricCollector  MetricCollector   `yaml:"metric_collector,omitempty"`
+	RulesCollectors  []*RulesCollector `yaml:"rules_collectors,omitempty"`
+	PersesCollector  PersesCollector   `yaml:"perses_collector,omitempty"`
+	GrafanaCollector GrafanaCollector  `yaml:"grafana_collector,omitempty"`
 }
 
 func Resolve(configFile string) (Config, error) {

dev/config.yaml

@@ -3,10 +3,10 @@ metric_collector:
   http_client:
     url: "https://prometheus.demo.do.prometheus.io"
 
-rules_collector:
-  enable: true
-  http_client:
-    url: "https://prometheus.demo.do.prometheus.io"
+rules_collectors:
+  - enable: true
+    http_client:
+      url: "https://prometheus.demo.do.prometheus.io"
 
 perses_collector:
   enable: true

main.go

@@ -37,13 +37,14 @@ func main() {
 		runner.WithTimerTasks(time.Duration(metricCollectorConfig.Period), metricCollector)
 	}
 
-	if conf.RulesCollector.Enable {
-		rulesCollectorConfig := conf.RulesCollector
-		rulesCollector, collectorErr := rules.NewCollector(db, rulesCollectorConfig)
-		if collectorErr != nil {
-			logrus.WithError(collectorErr).Fatal("unable to create the rules collector")
+	for i, rulesCollectorConfig := range conf.RulesCollectors {
+		if rulesCollectorConfig.Enable {
+			rulesCollector, collectorErr := rules.NewCollector(db, rulesCollectorConfig)
+			if collectorErr != nil {
+				logrus.WithError(collectorErr).Fatalf("unable to create the rules collector number %d", i)
+			}
+			runner.WithTimerTasks(time.Duration(rulesCollectorConfig.Period), rulesCollector)
 		}
-		runner.WithTimerTasks(time.Duration(rulesCollectorConfig.Period), rulesCollector)
 	}
 
 	if conf.PersesCollector.Enable {

source/rules/rules.go

@@ -13,7 +13,7 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-func NewCollector(db database.Database, cfg config.RulesCollector) (async.SimpleTask, error) {
+func NewCollector(db database.Database, cfg *config.RulesCollector) (async.SimpleTask, error) {
 	promClient, err := prometheus.NewClient(cfg.HTTPClient)
 	if err != nil {
 		return nil, err