add config parameter to suppress go metrics (#394)

* suppress Go metrics and document metrics settings

* changed metrics-settings back to metricsSettings

Author: KalmanMeth

README.md

@@ -757,8 +757,6 @@ parameters:
     encode:
       type: prom
       prom:
-        address: 0.0.0.0
-        port: 9103
         prefix: test_
         metrics:
           - name: Bytes
@@ -852,6 +850,25 @@ The object header contains the following fields: `version`, `capture_start_time`
 If no flow logs arrive within the `writeTimeout` period, then an object is created with no flows.
 An object is created either when we have accumulated `batchSize` flow logs or when `writeTimeout` has passed.
 
+### Metrics Settings
+
+Some global metrics settings may be set in the configuration file.
+A sample is the following:
+
+```
+metricsSettings:
+  suppressGoMetrics: true
+  prefix: flp_operational_
+  port: 9102
+
+```
+
+FLP metrics are reported to a prometheus client interface.
+In addition, there are default metrics reported by `Go`, which are also directed to the prometheus client interface.
+The port to which these metrics are made available is specified in the `port` configuration parameter.
+If a `prefix` is specified, then the specified prefix is prepended to each of the operational metrics generated by FLP.
+A different `prefix` may be specified on an `encode prom` stage to be prepended to the prometheus metrics defined in that stage.
+The `suppressGoMetrics` parameter may be set to `true` in order to suppress the reporting of the `Go` and process metrics in the prometheus client interface.
 
 # Development
 

cmd/flowlogs-pipeline/main.go

@@ -35,6 +35,7 @@ import (
 	"github.com/netobserv/flowlogs-pipeline/pkg/operational"
 	"github.com/netobserv/flowlogs-pipeline/pkg/pipeline"
 	"github.com/netobserv/flowlogs-pipeline/pkg/pipeline/utils"
+	"github.com/prometheus/client_golang/prometheus"
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
@@ -179,6 +180,13 @@ func run() {
 	// Setup (threads) exit manager
 	utils.SetupElegantExit()
 
+	// set up private prometheus registry
+	if cfg.MetricsSettings.SuppressGoMetrics {
+		reg := prometheus.NewRegistry()
+		prometheus.DefaultRegisterer = reg
+		prometheus.DefaultGatherer = reg
+	}
+
 	// create prometheus server for operational metrics
 	// if value of address is empty, then by default it will take 0.0.0.0
 	addr := fmt.Sprintf("%s:%v", cfg.MetricsSettings.Address, cfg.MetricsSettings.Port)

pkg/config/config.go

@@ -55,11 +55,12 @@ type Profile struct {
 // Also, currently FLP doesn't support defining more than one PromEncode stage. If this feature is added later, these global settings
 // will help configuring common setting for all PromEncode stages - PromEncode settings would then act as overrides.
 type MetricsSettings struct {
-	Address string           `yaml:"address,omitempty" json:"address,omitempty" doc:"address to expose \"/metrics\" endpoint"`
-	Port    int              `yaml:"port,omitempty" json:"port,omitempty" doc:"port number to expose \"/metrics\" endpoint"`
-	TLS     *api.PromTLSConf `yaml:"tls,omitempty" json:"tls,omitempty" doc:"TLS configuration for the prometheus endpoint"`
-	Prefix  string           `yaml:"prefix,omitempty" json:"prefix,omitempty"`
-	NoPanic bool             `yaml:"noPanic,omitempty" json:"noPanic,omitempty"`
+	Address           string           `yaml:"address,omitempty" json:"address,omitempty" doc:"address to expose \"/metrics\" endpoint"`
+	Port              int              `yaml:"port,omitempty" json:"port,omitempty" doc:"port number to expose \"/metrics\" endpoint"`
+	TLS               *api.PromTLSConf `yaml:"tls,omitempty" json:"tls,omitempty" doc:"TLS configuration for the prometheus endpoint"`
+	Prefix            string           `yaml:"prefix,omitempty" json:"prefix,omitempty" doc:"prefix for names of the operational metrics"`
+	NoPanic           bool             `yaml:"noPanic,omitempty" json:"noPanic,omitempty"`
+	SuppressGoMetrics bool             `yaml:"suppressGoMetrics,omitempty" json:"suppressGoMetrics,omitempty" doc:"filter out Go and process metrics"`
 }
 
 // PerfSettings allows setting some internal configuration parameters