Merge pull request #92 from grafana/activate-tracing

Allows to activate tracing.
grafana · Jul 19, 2022 · c5331fe · c5331fe
2 parents 83cea9c + 867bfe3
commit c5331fe
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Showing 4 changed files with 43 additions and 0 deletions.
diff --git a/deploy/helm/fire/templates/deployments-statefulsets.yaml b/deploy/helm/fire/templates/deployments-statefulsets.yaml
@@ -58,6 +58,13 @@ spec:
           {{- range $key, $value := $cfg.extraArgs }}
             - "-{{ $key }}={{ $value }}"
           {{- end }}
+          {{- with .Values.fire.extraEnvVars }}
+          env:
+           {{- range $key, $value := . }}
+            - name: {{ $key }}
+              value: {{ $value }}
+           {{- end }}
+          {{- end }}
           ports:
             - name: {{ .Values.fire.service.port_name }}
               containerPort: {{ .Values.fire.service.port }}

diff --git a/deploy/helm/fire/values.yaml b/deploy/helm/fire/values.yaml
@@ -16,6 +16,9 @@ fire:
     log.level: debug
 
   extraLabels: {}
+  extraEnvVars:
+    # The following environment variables are set by the Helm chart.
+    # JAEGER_AGENT_HOST: jaeger-agent.jaeger.svc.cluster.local.
 
   imagePullSecrets: []
   nameOverride: ""

diff --git a/pkg/fire/fire.go b/pkg/fire/fire.go
@@ -25,6 +25,7 @@ import (
 	"github.com/weaveworks/common/middleware"
 	"github.com/weaveworks/common/server"
 	"github.com/weaveworks/common/signals"
+	wwtracing "github.com/weaveworks/common/tracing"
 	"go.opentelemetry.io/otel/trace"
 	"google.golang.org/grpc/health/grpc_health_v1"
 
@@ -35,6 +36,7 @@ import (
 	"github.com/grafana/fire/pkg/gen/push/v1/pushv1connect"
 	"github.com/grafana/fire/pkg/ingester"
 	"github.com/grafana/fire/pkg/querier"
+	"github.com/grafana/fire/pkg/tracing"
 	"github.com/grafana/fire/pkg/util"
 )
 
@@ -47,6 +49,7 @@ type Config struct {
 	Ingester     ingester.Config        `yaml:"ingester,omitempty"`
 	MemberlistKV memberlist.KVConfig    `yaml:"memberlist"`
 	FireDB       firedb.Config          `yaml:"firedb,omitempty"`
+	Tracing      tracing.Config         `yaml:"tracing"`
 
 	AuthEnabled bool `yaml:"auth_enabled,omitempty"`
 	ConfigFile  string
@@ -66,6 +69,7 @@ func (c *Config) RegisterFlags(f *flag.FlagSet) {
 	c.Distributor.RegisterFlags(f)
 	c.Querier.RegisterFlags(f)
 	c.FireDB.RegisterFlags(f)
+	c.Tracing.RegisterFlags(f)
 }
 
 // registerServerFlagsWithChangedDefaultValues registers *Config.Server flags, but overrides some defaults set by the weaveworks package.
@@ -164,6 +168,22 @@ func New(cfg Config) (*Fire, error) {
 		return nil, err
 	}
 
+	if cfg.Tracing.Enabled {
+		// Setting the environment variable JAEGER_AGENT_HOST enables tracing
+		trace, err := wwtracing.NewFromEnv(fmt.Sprintf("fire-%s", cfg.Target))
+		if err != nil {
+			level.Error(logger).Log("msg", "error in initializing tracing. tracing will not be enabled", "err", err)
+		}
+
+		defer func() {
+			if trace != nil {
+				if err := trace.Close(); err != nil {
+					level.Error(logger).Log("msg", "error closing tracing", "err", err)
+				}
+			}
+		}()
+	}
+
 	// instantiate a fallback pusher client (when not run with a local distributor
 	pusherHTTPClient, err := commonconfig.NewClientFromConfig(cfg.AgentConfig.ClientConfig.Client, cfg.AgentConfig.ClientConfig.URL.String())
 	if err != nil {

diff --git a/pkg/tracing/config.go b/pkg/tracing/config.go
@@ -0,0 +1,13 @@
+package tracing
+
+import (
+	"flag"
+)
+
+type Config struct {
+	Enabled bool `yaml:"enabled"`
+}
+
+func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
+	f.BoolVar(&cfg.Enabled, "tracing.enabled", true, "Set to false to disable tracing.")
+}