explicitly set MaxIdleConns, so that it is clear we need to update it when increasing MaxIdleConnsPerHost

4 files changed, 26 insertions, 10 deletions

diff --git a/internal/artifact/artifact.go b/internal/artifact/artifact.go
index 91ecbcf8..ef173d9e 100644
--- a/internal/artifact/artifact.go
+++ b/internal/artifact/artifact.go
@@ -51,7 +51,7 @@ func New(server string, timeoutSeconds int, pagesDomain string) *Artifact {
 		suffix: "." + strings.ToLower(pagesDomain),
 		client: &http.Client{
 			Timeout:   time.Second * time.Duration(timeoutSeconds),
-			Transport: httptransport.Transport,
+			Transport: httptransport.InternalTransport,
 		},
 	}
 }
diff --git a/internal/auth/auth.go b/internal/auth/auth.go
index f30c7407..c582d96b 100644
--- a/internal/auth/auth.go
+++ b/internal/auth/auth.go
@@ -618,7 +618,7 @@ func New(pagesDomain string, storeSecret string, clientID string, clientSecret s
 		gitLabServer: strings.TrimRight(gitLabServer, "/"),
 		apiClient: &http.Client{
 			Timeout:   5 * time.Second,
-			Transport: httptransport.Transport,
+			Transport: httptransport.InternalTransport,
 		},
 		store: createCookieStore(storeSecret),
 	}
diff --git a/internal/httptransport/transport.go b/internal/httptransport/transport.go
index ba2aa5eb..78da6e99 100644
--- a/internal/httptransport/transport.go
+++ b/internal/httptransport/transport.go
@@ -19,13 +19,8 @@ var (
 	sysPoolOnce = &sync.Once{}
 	sysPool     *x509.CertPool
 
-	// Transport can be used with http.Client with TLS and certificates
-	Transport = &http.Transport{
-		DialTLS: func(network, addr string) (net.Conn, error) {
-			return tls.Dial(network, addr, &tls.Config{RootCAs: pool()})
-		},
-		Proxy: http.ProxyFromEnvironment,
-	}
+	// InternalTransport can be used with http.Client with TLS and certificates
+	InternalTransport = newInternalTransport()
 )
 
 type meteredRoundTripper struct {
@@ -34,11 +29,24 @@ type meteredRoundTripper struct {
 	counter   *prometheus.CounterVec
 }
 
+func newInternalTransport() *http.Transport {
+	return &http.Transport{
+		DialTLS: func(network, addr string) (net.Conn, error) {
+			return tls.Dial(network, addr, &tls.Config{RootCAs: pool()})
+		},
+		Proxy: http.ProxyFromEnvironment,
+		// overrides the DefaultMaxIdleConnsPerHost = 2
+		MaxIdleConns:        100,
+		MaxIdleConnsPerHost: 100,
+		IdleConnTimeout:     90 * time.Second,
+	}
+}
+
 // NewTransportWithMetrics will create a custom http.RoundTripper that can be used with an http.Client.
 // The RoundTripper will report metrics based on the collectors passed.
 func NewTransportWithMetrics(gaugeVec *prometheus.GaugeVec, counterVec *prometheus.CounterVec) http.RoundTripper {
 	return &meteredRoundTripper{
-		next:      Transport,
+		next:      InternalTransport,
 		durations: gaugeVec,
 		counter:   counterVec,
 	}
diff --git a/internal/httptransport/transport_test.go b/internal/httptransport/transport_test.go
index cfb8d708..e3270ebe 100644
--- a/internal/httptransport/transport_test.go
+++ b/internal/httptransport/transport_test.go
@@ -6,6 +6,7 @@ import (
 	"net/http/httptest"
 	"strconv"
 	"testing"
+	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/testutil"
@@ -89,3 +90,10 @@ type mockRoundTripper struct {
 func (mrt *mockRoundTripper) RoundTrip(r *http.Request) (*http.Response, error) {
 	return mrt.res, mrt.err
 }
+
+func TestInternalTransportShouldHaveCustomConnectionPoolSettings(t *testing.T) {
+	require.EqualValues(t, 100, InternalTransport.MaxIdleConns)
+	require.EqualValues(t, 100, InternalTransport.MaxIdleConnsPerHost)
+	require.EqualValues(t, 0, InternalTransport.MaxConnsPerHost)
+	require.EqualValues(t, 90*time.Second, InternalTransport.IdleConnTimeout)
+}