support adding arbitrary extra tags in jaeger traces

Author: Dieterbe

cmd/mt-store-cat/main.go

@@ -167,7 +167,7 @@ func main() {
 	if err != nil {
 		log.Fatal(4, "failed to initialize cassandra. %s", err)
 	}
-	tracer, traceCloser, err := conf.GetTracer(false, "")
+	tracer, traceCloser, err := conf.GetTracer(false, "", nil)
 	if err != nil {
 		log.Fatal(4, "Could not initialize jaeger tracer: %s", err.Error())
 	}

conf/tracing.go

@@ -9,7 +9,9 @@ import (
 	jaegerlog "github.com/uber/jaeger-client-go/log"
 )
 
-func GetTracer(enabled bool, addr string) (opentracing.Tracer, io.Closer, error) {
+// GetTracer returns a jaeger tracer
+// any tags specified will be added as process/tracer-level tags
+func GetTracer(enabled bool, addr string, tags map[string]string) (opentracing.Tracer, io.Closer, error) {
 	// Sample configuration for testing. Use constant sampling to sample every trace
 	// and enable LogSpan to log every span via configured Logger.
 	cfg := jaegercfg.Configuration{
@@ -26,9 +28,16 @@ func GetTracer(enabled bool, addr string) (opentracing.Tracer, io.Closer, error)
 
 	jLogger := jaegerlog.StdLogger
 
+	options := []jaegercfg.Option{
+		jaegercfg.Logger(jLogger),
+	}
+	for k, v := range tags {
+		options = append(options, jaegercfg.Tag(k, v))
+	}
+
 	tracer, closer, err := cfg.New(
 		"metrictank",
-		jaegercfg.Logger(jLogger),
+		options...,
 	)
 	if err != nil {
 		return nil, nil, err

docker/docker-chaos/metrictank.ini

@@ -97,6 +97,8 @@ log-level = 2
 tracing-enabled = true
 # address of the jaeger agent to send data to
 tracing-addr = jaeger:6831
+# tracer/process-level tags to include, specified as comma-separated key:value pairs
+tracing-add-tags =
 
 ## Retention settings ##
 [retention]

docker/docker-cluster/metrictank.ini

@@ -97,6 +97,8 @@ log-level = 2
 tracing-enabled = true
 # address of the jaeger agent to send data to
 tracing-addr = jaeger:6831
+# tracer/process-level tags to include, specified as comma-separated key:value pairs
+tracing-add-tags =
 
 ## Retention settings ##
 [retention]

docker/docker-dev-custom-cfg-kafka/metrictank.ini

@@ -97,6 +97,8 @@ log-level = 2
 tracing-enabled = false
 # address of the jaeger agent to send data to
 tracing-addr = localhost:6831
+# tracer/process-level tags to include, specified as comma-separated key:value pairs
+tracing-add-tags =
 
 ## Retention settings ##
 [retention]

docs/config.md

@@ -126,6 +126,8 @@ log-level = 2
 tracing-enabled = false
 # address of the jaeger agent to send data to
 tracing-addr = localhost:6831
+# tracer/process-level tags to include, specified as comma-separated key:value pairs
+tracing-add-tags =
 ```
 
 ## Retention settings ##

metrictank-sample.ini

@@ -100,6 +100,8 @@ log-level = 2
 tracing-enabled = false
 # address of the jaeger agent to send data to
 tracing-addr = localhost:6831
+# tracer/process-level tags to include, specified as comma-separated key:value pairs
+tracing-add-tags =
 
 ## Retention settings ##
 [retention]

metrictank.go

@@ -101,6 +101,7 @@ var (
 
 	tracingEnabled = flag.Bool("tracing-enabled", false, "enable/disable distributed opentracing via jaeger")
 	tracingAddr    = flag.String("tracing-addr", "localhost:6831", "address of the jaeger agent to send data to")
+	tracingAddTags = flag.String("tracing-add-tags", "", "tracer/process-level tags to include, specified as comma-separated key:value pairs")
 )
 
 func init() {
@@ -270,7 +271,16 @@ func main() {
 	/***********************************
 		Initialize tracer
 	***********************************/
-	tracer, traceCloser, err := conf.GetTracer(*tracingEnabled, *tracingAddr)
+	tagSpecs := strings.Split(strings.TrimSpace(*tracingAddTags), ",")
+	tags := make(map[string]string)
+	for _, tagSpec := range tagSpecs {
+		split := strings.Split(tagSpec, ":")
+		if len(split) != 2 {
+			log.Fatal(4, "cannot parse tracing-add-tags value %q", tagSpec)
+		}
+		tags[split[0]] = split[1]
+	}
+	tracer, traceCloser, err := conf.GetTracer(*tracingEnabled, *tracingAddr, tags)
 	if err != nil {
 		log.Fatal(4, "Could not initialize jaeger tracer: %s", err.Error())
 	}

scripts/config/metrictank-docker.ini

@@ -97,6 +97,8 @@ log-level = 2
 tracing-enabled = false
 # address of the jaeger agent to send data to
 tracing-addr = localhost:6831
+# tracer/process-level tags to include, specified as comma-separated key:value pairs
+tracing-add-tags =
 
 ## Retention settings ##
 [retention]

scripts/config/metrictank-package.ini

@@ -97,6 +97,8 @@ log-level = 2
 tracing-enabled = false
 # address of the jaeger agent to send data to
 tracing-addr = localhost:6831
+# tracer/process-level tags to include, specified as comma-separated key:value pairs
+tracing-add-tags =
 
 ## Retention settings ##
 [retention]