From 23d5ab148a5d2df89512c2e62a7c991b328589c0 Mon Sep 17 00:00:00 2001
From: Cyril Tovena <cyril.tovena@gmail.com>
Date: Tue, 19 Jul 2022 14:38:57 +0200
Subject: [PATCH 1/2] Add http client instrumentation

---
 pkg/fire/fire.go                              |  1 +
 .../clientpool/ingester_client_pool.go        |  4 +-
 pkg/util/http.go                              | 47 +++++++++++++++++++
 3 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100644 pkg/util/http.go

diff --git a/pkg/fire/fire.go b/pkg/fire/fire.go
index db9b086ba2..8717203f03 100644
--- a/pkg/fire/fire.go
+++ b/pkg/fire/fire.go
@@ -169,6 +169,7 @@ func New(cfg Config) (*Fire, error) {
 	if err != nil {
 		return nil, err
 	}
+	pusherHTTPClient.Transport = util.WrapWithInstrumentedHTTPTransport(pusherHTTPClient.Transport)
 	fire.pusherClient = pushv1connect.NewPusherServiceClient(pusherHTTPClient, cfg.AgentConfig.ClientConfig.URL.String())
 
 	return fire, nil
diff --git a/pkg/ingester/clientpool/ingester_client_pool.go b/pkg/ingester/clientpool/ingester_client_pool.go
index 180f3bc4d9..02b80dedb4 100644
--- a/pkg/ingester/clientpool/ingester_client_pool.go
+++ b/pkg/ingester/clientpool/ingester_client_pool.go
@@ -3,7 +3,6 @@ package clientpool
 import (
 	"flag"
 	"io"
-	"net/http"
 	"time"
 
 	"github.com/go-kit/log"
@@ -14,6 +13,7 @@ import (
 	"google.golang.org/grpc/health/grpc_health_v1"
 
 	"github.com/grafana/fire/pkg/gen/ingester/v1/ingesterv1connect"
+	"github.com/grafana/fire/pkg/util"
 )
 
 // PoolConfig is config for creating a Pool.
@@ -49,7 +49,7 @@ func PoolFactory(addr string) (ring_client.PoolClient, error) {
 		return nil, err
 	}
 	return &ingesterPoolClient{
-		IngesterServiceClient: ingesterv1connect.NewIngesterServiceClient(http.DefaultClient, "http://"+addr),
+		IngesterServiceClient: ingesterv1connect.NewIngesterServiceClient(util.InstrumentedHTTPClient(), "http://"+addr),
 		HealthClient:          grpc_health_v1.NewHealthClient(conn),
 		Closer:                conn,
 	}, nil
diff --git a/pkg/util/http.go b/pkg/util/http.go
new file mode 100644
index 0000000000..a584946337
--- /dev/null
+++ b/pkg/util/http.go
@@ -0,0 +1,47 @@
+package util
+
+import (
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/opentracing-contrib/go-stdlib/nethttp"
+	"github.com/opentracing/opentracing-go"
+)
+
+var defaultTransport http.RoundTripper = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
+	DialContext: (&net.Dialer{
+		Timeout:   30 * time.Second,
+		KeepAlive: 30 * time.Second,
+	}).DialContext,
+	ForceAttemptHTTP2:     true,
+	MaxIdleConns:          200,
+	MaxIdleConnsPerHost:   200,
+	IdleConnTimeout:       90 * time.Second,
+	TLSHandshakeTimeout:   10 * time.Second,
+	ExpectContinueTimeout: 1 * time.Second,
+}
+
+type RoundTripperFunc func(req *http.Request) (*http.Response, error)
+
+func (f RoundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) {
+	return f(req)
+}
+
+// InstrumentedHTTPClient returns a HTTP client with tracing instrumented default RoundTripper.
+func InstrumentedHTTPClient() *http.Client {
+	return &http.Client{
+		Transport: WrapWithInstrumentedHTTPTransport(defaultTransport),
+	}
+}
+
+// WrapWithInstrumentedHTTPTransport wraps the given RoundTripper with an tracing instrumented one.
+func WrapWithInstrumentedHTTPTransport(next http.RoundTripper) http.RoundTripper {
+	next = &nethttp.Transport{RoundTripper: next}
+	return RoundTripperFunc(func(req *http.Request) (*http.Response, error) {
+		req, tr := nethttp.TraceRequest(opentracing.GlobalTracer(), req)
+		defer tr.Finish()
+		return next.RoundTrip(req)
+	})
+}

From 6edc23416e2bf53e8f26364a2a9f2322f20bbc31 Mon Sep 17 00:00:00 2001
From: Cyril Tovena <cyril.tovena@gmail.com>
Date: Tue, 19 Jul 2022 14:52:28 +0200
Subject: [PATCH 2/2] make go/mod

---
 go.mod | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/go.mod b/go.mod
index b8d831869b..499a7a3cef 100644
--- a/go.mod
+++ b/go.mod
@@ -18,6 +18,7 @@ require (
 	github.com/klauspost/compress v1.15.7
 	github.com/oklog/ulid v1.3.1
 	github.com/olekukonko/tablewriter v0.0.5
+	github.com/opentracing-contrib/go-stdlib v1.0.0
 	github.com/opentracing/opentracing-go v1.2.0
 	github.com/parca-dev/parca v0.11.1-0.20220628070043-1c1a82d2d7bd
 	github.com/pkg/errors v0.9.1
@@ -196,7 +197,6 @@ require (
 	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/opencontainers/image-spec v1.0.2 // indirect
 	github.com/opentracing-contrib/go-grpc v0.0.0-20210225150812-73cb765af46e // indirect
-	github.com/opentracing-contrib/go-stdlib v1.0.0 // indirect
 	github.com/pierrec/lz4/v4 v4.1.15 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prometheus/client_model v0.2.0 // indirect