feat: Add tracing integration to profiling. (#11633)

Same as grafana/tempo#3276 this adds profiling
integration to tracing instrumentation allowing to get profile for a
single request removing the noise of everything else.

CHANGELOG.md

@@ -6,7 +6,8 @@
 
 ##### Enhancements
 
-* [11571](https://github.com/grafana/loki/pull/11571) **MichelHollands**: Add a metrics.go log line for requests from querier to ingester 
+* [11633](https://github.com/grafana/loki/pull/11633) **cyriltovena**: Add profiling integrations to tracing instrumentation.
+* [11571](https://github.com/grafana/loki/pull/11571) **MichelHollands**: Add a metrics.go log line for requests from querier to ingester
 * [11477](https://github.com/grafana/loki/pull/11477) **MichelHollands**: support GET for /ingester/shutdown
 * [11363](https://github.com/grafana/loki/pull/11363) **kavirajk**: bugfix(memcached): Make memcached batch fetch truely context aware.
 * [11319](https://github.com/grafana/loki/pull/11319) **someStrangerFromTheAbyss**: Helm: Add extraContainers to the write pods.

cmd/loki/main.go

@@ -10,7 +10,9 @@ import (
 
 	"github.com/go-kit/log/level"
 	"github.com/grafana/dskit/log"
+	"github.com/grafana/dskit/spanprofiler"
 	"github.com/grafana/dskit/tracing"
+	"github.com/opentracing/opentracing-go"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/version"
 
@@ -84,7 +86,9 @@ func main() {
 		if err != nil {
 			level.Error(util_log.Logger).Log("msg", "error in initializing tracing. tracing will not be enabled", "err", err)
 		}
-
+		if config.Tracing.ProfilingEnabled {
+			opentracing.SetGlobalTracer(spanprofiler.NewTracer(opentracing.GlobalTracer()))
+		}
 		defer func() {
 			if trace != nil {
 				if err := trace.Close(); err != nil {

pkg/tracing/config.go

@@ -5,7 +5,8 @@ import (
 )
 
 type Config struct {
-	Enabled bool `yaml:"enabled"`
+	Enabled          bool `yaml:"enabled"`
+	ProfilingEnabled bool `yaml:"profiling_enabled" category:"experimental" doc:"hidden"`
 }
 
 func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
@@ -14,4 +15,5 @@ func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
 
 func (cfg *Config) RegisterFlagsWithPrefix(prefix string, f *flag.FlagSet) {
 	f.BoolVar(&cfg.Enabled, prefix+"tracing.enabled", true, "Set to false to disable tracing.")
+	f.BoolVar(&cfg.ProfilingEnabled, prefix+"tracing.profiling-enabled", true, "Set to true to enable profiling integration.")
 }

vendor/modules.txt

@@ -894,6 +894,7 @@ github.com/grafana/dskit/server
 github.com/grafana/dskit/services
 github.com/grafana/dskit/signals
 github.com/grafana/dskit/spanlogger
+github.com/grafana/dskit/spanprofiler
 github.com/grafana/dskit/tenant
 github.com/grafana/dskit/test
 github.com/grafana/dskit/tracing