Merge pull request #419 from hellofresh/feature/respect-parent-sampler

Respect parent sampling decision if not public endpoint

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 - None
 
+# 3.8.13
+- Changed trace sampling behavior when `TRACING_IS_PUBLIC_ENDPOINT` is set to false
+
 # 3.8.12
 
 ## Added
@@ -55,7 +58,7 @@
 ## Fixed
 
 - Circuit breaker plugin statsd collector prefix
- 
+
 # 3.8.6
 
 ## Updated

cmd/init.go

@@ -10,6 +10,7 @@ import (
 	"github.com/hellofresh/janus/pkg/config"
 	obs "github.com/hellofresh/janus/pkg/observability"
 	"github.com/hellofresh/logging-go"
+	_trace "github.com/hellofresh/opencensus-go-extras/trace"
 	"github.com/hellofresh/stats-go"
 	"github.com/hellofresh/stats-go/bucket"
 	"github.com/hellofresh/stats-go/client"
@@ -171,23 +172,29 @@ func initTracingExporter() {
 	}
 
 	var traceConfig trace.Config
+	var sampler trace.Sampler
 	logger = logger.WithField("tracing.samplingStrategy", globalConfig.Tracing.SamplingStrategy)
 
 	switch globalConfig.Tracing.SamplingStrategy {
 	case "always":
-		traceConfig.DefaultSampler = trace.AlwaysSample()
+		sampler = trace.AlwaysSample()
 		break
 	case "never":
-		traceConfig.DefaultSampler = trace.NeverSample()
+		sampler = trace.NeverSample()
 		break
 	case "probabilistic":
-		traceConfig.DefaultSampler = trace.ProbabilitySampler(globalConfig.Tracing.SamplingParam)
+		sampler = trace.ProbabilitySampler(globalConfig.Tracing.SamplingParam)
 		break
 	default:
 		logger.Warn("Invalid tracing sampling strategy specified")
 		return
 	}
 
+	if !globalConfig.Tracing.IsPublicEndpoint {
+		sampler = _trace.RespectParentSampler(sampler)
+	}
+
+	traceConfig.DefaultSampler = sampler
 	trace.ApplyConfig(traceConfig)
 }
 

go.mod

@@ -27,6 +27,7 @@ require (
 	github.com/hashicorp/hcl v0.0.0-20171017181929-23c074d0eceb // indirect
 	github.com/hellofresh/health-go v1.2.6
 	github.com/hellofresh/logging-go v0.1.6
+	github.com/hellofresh/opencensus-go-extras v0.0.0-20191004131501-7bd94f603dcf
 	github.com/hellofresh/stats-go v0.8.0
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/kelseyhightower/envconfig v1.3.0
@@ -58,7 +59,7 @@ require (
 	github.com/ulule/limiter v2.2.2+incompatible
 	go.opencensus.io v0.18.0
 	golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586 // indirect
-	golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7
+	golang.org/x/net v0.0.0-20191003171128-d98b1b443823
 	golang.org/x/oauth2 v0.0.0-20180118004544-b28fcf2b08a1
 	golang.org/x/sync v0.0.0-20190423024810-112230192c58 // indirect
 	golang.org/x/sys v0.0.0-20190825160603-fb81701db80f // indirect

go.sum

@@ -59,6 +59,8 @@ github.com/hellofresh/health-go v1.2.6 h1:qL3H7n3Vjz1tR9F6yvs5jO5IKh0e7ptIt+/1aD
 github.com/hellofresh/health-go v1.2.6/go.mod h1:/lE+J/PDTYpbLHXGSzpRSRaF5fUegajdWaXfYW9dWQQ=
 github.com/hellofresh/logging-go v0.1.6 h1:cY/pZ7Doo+jm+AyFY+MnwBsS8sxF1LN8DEVke2xNmXI=
 github.com/hellofresh/logging-go v0.1.6/go.mod h1:gwpkafA8SxN1O16aSWH4DMCp0+48miJHeeyaI5bl6HY=
+github.com/hellofresh/opencensus-go-extras v0.0.0-20191004131501-7bd94f603dcf h1:Y1JRm9uNFp5Mo5RIGKcR+Q/PbrLfoDrn4kqk8HRJ7s0=
+github.com/hellofresh/opencensus-go-extras v0.0.0-20191004131501-7bd94f603dcf/go.mod h1:lQT0hUJcZDvyxgDnhIeDnK3sPgyEP8Okk3SxCa0M8ZU=
 github.com/hellofresh/stats-go v0.8.0 h1:rWMeTJ/9FU7Hob/Ci7j1wa9pHfNj8LtdUYNC6jLcT2s=
 github.com/hellofresh/stats-go v0.8.0/go.mod h1:8ukhFqK19hqGqF1SyR7ljKBUztsYDxvYRevJ9oOZzhQ=
 github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
@@ -134,6 +136,7 @@ github.com/tidwall/match v1.0.0 h1:Ym1EcFkp+UQ4ptxfWlW+iMdq5cPH5nEuGzdf/Pb7VmI=
 github.com/tidwall/match v1.0.0/go.mod h1:LujAq0jyVjBy028G1WhWfIzbpQfMO8bBZ6Tyb0+pL9E=
 github.com/ulule/limiter v2.2.2+incompatible h1:1lk9jesmps1ziYHHb4doL7l5hFkYYYA3T8dkNyw7ffY=
 github.com/ulule/limiter v2.2.2+incompatible/go.mod h1:VJx/ZNGmClQDS5F6EmsGqK8j3jz1qJYZ6D9+MdAD+kw=
+go.opencensus.io v0.10.0/go.mod h1:UffZAU+4sDEINUGP/B7UfBBkq4fqLu9zXAX7ke6CHW0=
 go.opencensus.io v0.18.0 h1:Mk5rgZcggtbvtAun5aJzAtjKKN/t0R3jJPlWILlv938=
 go.opencensus.io v0.18.0/go.mod h1:vKdFvxhtzZ9onBp9VKHK8z/sRpBMnKAsufL7wlDrCOA=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
@@ -145,6 +148,8 @@ golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7 h1:fHDIZ2oxGnUZRN6WgWFCbYBjH9uqVPRCUVUDhs0wnbA=
 golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20191003171128-d98b1b443823 h1:Ypyv6BNJh07T1pUSrehkLemqPKXhus2MkfktJ91kRh4=
+golang.org/x/net v0.0.0-20191003171128-d98b1b443823/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/oauth2 v0.0.0-20180118004544-b28fcf2b08a1 h1:gRThnsUxGd2h5EB2AOiqLcAxfMF3Y2LQCeru8REL+p0=
 golang.org/x/oauth2 v0.0.0-20180118004544-b28fcf2b08a1/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f h1:wMNYb4v58l5UBM7MYRLPG6ZhfOqbKu7X5eyFl8ZhKvA=