[Feature] Expose HTTP Client Config (#1680)

CHANGELOG.md

@@ -4,6 +4,7 @@
 - (Maintenance) Go 1.22.4 & Kubernetes 1.29.6 libraries
 - (Feature) Fix CRD Schema types
 - (Bugfix) Adjust Prometheus Monitor labels
+- (Feature) Expose HTTP Client Config
 
 ## [1.2.41](https://github.com/arangodb/kube-arangodb/tree/1.2.41) (2024-05-24)
 - (Maintenance) Bump Prometheus API Version

README.md

@@ -166,6 +166,14 @@ Flags:
       --deployment.feature.upgrade-version-check               Enable initContainer with pre version check - Required ArangoDB 3.8.0 or higher (default true)
       --deployment.feature.upgrade-version-check-v2            Enable initContainer with pre version check based by Operator - Required ArangoDB 3.8.0 or higher
       --features-config-map-name string                        Name of the Feature Map ConfigMap (default "arangodb-operator-feature-config-map")
+      --http1.keep-alive                                       If false, disables HTTP keep-alives and will only use the connection to the server for a single HTTP request (default true)
+      --http1.transport.dial-timeout duration                  Maximum amount of time a dial will wait for a connect to complete (default 30s)
+      --http1.transport.idle-conn-timeout duration             Maximum amount of time an idle (keep-alive) connection will remain idle before closing itself. Zero means no limit (default 1m30s)
+      --http1.transport.idle-conn-timeout-short duration       Maximum amount of time an idle (keep-alive) connection will remain idle before closing itself. Zero means no limit (default 100ms)
+      --http1.transport.keep-alive-timeout duration            Interval between keep-alive probes for an active network connection (default 1m30s)
+      --http1.transport.keep-alive-timeout-short duration      Interval between keep-alive probes for an active network connection (default 100ms)
+      --http1.transport.max-idle-conns int                     Maximum number of idle (keep-alive) connections across all hosts. Zero means no limit (default 100)
+      --http1.transport.tls-handshake-timeout duration         Maximum amount of time to wait for a TLS handshake. Zero means no timeout (default 10s)
       --image.discovery.status                                 Discover Operator Image from Pod Status by default. When disabled Pod Spec is used. (default true)
       --image.discovery.timeout duration                       Timeout for image discovery process (default 1m0s)
       --internal.scaling-integration                           Enable Scaling Integration

cmd/cmd.go

@@ -262,6 +262,9 @@ func init() {
 	if err := reconcile.ActionsConfigGlobal.Init(&cmdMain); err != nil {
 		panic(err.Error())
 	}
+	if err := operatorHTTP.InitConfiguration(&cmdMain); err != nil {
+		panic(err.Error())
+	}
 }
 
 func Command() *cobra.Command {

pkg/deployment/context_impl.go

@@ -22,12 +22,9 @@ package deployment
 
 import (
 	"context"
-	"crypto/tls"
 	"fmt"
 	"net"
-	nhttp "net/http"
 	"strconv"
-	"time"
 
 	core "k8s.io/api/core/v1"
 	apiErrors "k8s.io/apimachinery/pkg/api/errors"
@@ -53,9 +50,11 @@ import (
 	"github.com/arangodb/kube-arangodb/pkg/deployment/resources"
 	"github.com/arangodb/kube-arangodb/pkg/operator/scope"
 	"github.com/arangodb/kube-arangodb/pkg/replication"
+	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/constants"
 	"github.com/arangodb/kube-arangodb/pkg/util/errors"
 	"github.com/arangodb/kube-arangodb/pkg/util/globals"
+	operatorHTTP "github.com/arangodb/kube-arangodb/pkg/util/http"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 	inspectorInterface "github.com/arangodb/kube-arangodb/pkg/util/k8sutil/inspector"
 	persistentvolumeclaimv1 "github.com/arangodb/kube-arangodb/pkg/util/k8sutil/inspector/persistentvolumeclaim/v1"
@@ -219,24 +218,7 @@ func (d *Deployment) GetAgency(ctx context.Context, agencyIDs ...string) (agency
 }
 
 func (d *Deployment) getConnConfig() (http.ConnectionConfig, error) {
-	transport := &nhttp.Transport{
-		Proxy: nhttp.ProxyFromEnvironment,
-		DialContext: (&net.Dialer{
-			Timeout:   10 * time.Second,
-			KeepAlive: 100 * time.Millisecond,
-			DualStack: true,
-		}).DialContext,
-		MaxIdleConns:          100,
-		IdleConnTimeout:       100 * time.Millisecond,
-		TLSHandshakeTimeout:   10 * time.Second,
-		ExpectContinueTimeout: 1 * time.Second,
-	}
-
-	if d.GetSpec().TLS.IsSecure() {
-		transport.TLSClientConfig = &tls.Config{
-			InsecureSkipVerify: true,
-		}
-	}
+	transport := operatorHTTP.RoundTripperWithShortTransport(operatorHTTP.WithTransportTLS(util.BoolSwitch(d.GetSpec().TLS.IsSecure(), operatorHTTP.Insecure, nil)))
 
 	connConfig := http.ConnectionConfig{
 		Transport:          transport,

pkg/deployment/reconcile/plan_builder_tls.go

@@ -1,7 +1,7 @@
 //
 // DISCLAIMER
 //
-// Copyright 2016-2023 ArangoDB GmbH, Cologne, Germany
+// Copyright 2016-2024 ArangoDB GmbH, Cologne, Germany
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -43,6 +43,7 @@ import (
 	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/constants"
 	"github.com/arangodb/kube-arangodb/pkg/util/crypto"
+	operatorHTTP "github.com/arangodb/kube-arangodb/pkg/util/http"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 	inspectorInterface "github.com/arangodb/kube-arangodb/pkg/util/k8sutil/inspector"
 	memberTls "github.com/arangodb/kube-arangodb/pkg/util/k8sutil/tls"
@@ -450,10 +451,7 @@ func checkServerValidCertRequest(ctx context.Context, context PlanBuilderContext
 		endpoint = fmt.Sprintf("https://%s:%d%s", k8sutil.CreatePodDNSNameWithDomain(apiObject, context.GetSpec().ClusterDomain, group.AsRole(), member.ID), shared.ArangoSyncMasterPort, shared.ArangoSyncStatusEndpoint)
 	}
 
-	tlsConfig := &tls.Config{
-		RootCAs: ca.AsCertPool(),
-	}
-	transport := &http.Transport{TLSClientConfig: tlsConfig}
+	transport := operatorHTTP.RoundTripper(operatorHTTP.WithTransportTLS(operatorHTTP.WithRootCA(ca.AsCertPool())))
 	client := &http.Client{Transport: transport, Timeout: time.Second}
 
 	auth, err := context.GetAuthentication()()

pkg/exporter/passthru.go

@@ -21,14 +21,15 @@
 package exporter
 
 import (
-	"crypto/tls"
 	"io"
 	"net/http"
 	"strings"
 	"sync"
 	"time"
 
+	"github.com/arangodb/kube-arangodb/pkg/util"
 	"github.com/arangodb/kube-arangodb/pkg/util/errors"
+	operatorHTTP "github.com/arangodb/kube-arangodb/pkg/util/http"
 )
 
 var _ http.Handler = &passthru{}
@@ -44,17 +45,13 @@ type httpClientFactory func(endpoint string) (*http.Client, *http.Request, error
 
 func newHttpClientFactory(auth Authentication, sslVerify bool, timeout time.Duration) httpClientFactory {
 	return func(endpoint string) (*http.Client, *http.Request, error) {
-		transport := &http.Transport{}
+		transport := operatorHTTP.Transport(operatorHTTP.WithTransportTLS(util.BoolSwitch(sslVerify, operatorHTTP.Insecure, nil)))
 
 		req, err := http.NewRequest("GET", endpoint, nil)
 		if err != nil {
 			return nil, nil, errors.WithStack(err)
 		}
 
-		if !sslVerify {
-			transport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
-		}
-
 		jwt, err := auth()
 		if err != nil {
 			return nil, nil, err

pkg/storage/provisioner/client/client.go

@@ -23,16 +23,15 @@ package client
 import (
 	"bytes"
 	"context"
-	"crypto/tls"
 	"encoding/json"
 	"io"
-	"net"
 	"net/http"
 	"net/url"
 	"time"
 
 	"github.com/arangodb/kube-arangodb/pkg/storage/provisioner"
 	"github.com/arangodb/kube-arangodb/pkg/util/errors"
+	operatorHTTP "github.com/arangodb/kube-arangodb/pkg/util/http"
 )
 
 // New creates a new client for the provisioner API.
@@ -44,39 +43,23 @@ func New(endpoint string) (provisioner.API, error) {
 	u.Path = ""
 	return &client{
 		endpoint: *u,
+		client: &http.Client{
+			Transport: operatorHTTP.RoundTripper(operatorHTTP.WithTransportTLS(operatorHTTP.Insecure)),
+			Timeout:   defaultHTTPTimeout,
+		},
 	}, nil
 }
 
 type client struct {
 	endpoint url.URL
+
+	client *http.Client
 }
 
 const (
 	defaultHTTPTimeout = time.Minute * 2
 )
 
-var (
-	httpClient = &http.Client{
-		Timeout: defaultHTTPTimeout,
-		Transport: &http.Transport{
-			Proxy: http.ProxyFromEnvironment,
-			DialContext: (&net.Dialer{
-				Timeout:   30 * time.Second,
-				KeepAlive: 30 * time.Second,
-				DualStack: true,
-			}).DialContext,
-			MaxIdleConns:        100,
-			MaxIdleConnsPerHost: 10,
-			IdleConnTimeout:     90 * time.Second,
-			TLSHandshakeTimeout: 90 * time.Second,
-			TLSClientConfig: &tls.Config{
-				InsecureSkipVerify: true,
-			},
-			ExpectContinueTimeout: 1 * time.Second,
-		},
-	}
-)
-
 // GetNodeInfo fetches information from the current node.
 func (c *client) GetNodeInfo(ctx context.Context) (provisioner.NodeInfo, error) {
 	req, err := c.newRequest("GET", "/nodeinfo", nil)
@@ -165,7 +148,7 @@ func (c *client) newRequest(method string, localPath string, body interface{}) (
 // do performs the given request and parses the result.
 func (c *client) do(ctx context.Context, req *http.Request, result interface{}) error {
 	req = req.WithContext(ctx)
-	resp, err := httpClient.Do(req)
+	resp, err := c.client.Do(req)
 	if err != nil {
 		// Request failed
 		return errors.WithStack(err)

pkg/util/arangod/client.go

@@ -22,11 +22,9 @@ package arangod
 
 import (
 	"context"
-	"crypto/tls"
 	"net"
 	nhttp "net/http"
 	"strconv"
-	"time"
 
 	typedCore "k8s.io/client-go/kubernetes/typed/core/v1"
 
@@ -39,6 +37,7 @@ import (
 	shared "github.com/arangodb/kube-arangodb/pkg/apis/shared"
 	"github.com/arangodb/kube-arangodb/pkg/util/errors"
 	"github.com/arangodb/kube-arangodb/pkg/util/globals"
+	operatorHTTP "github.com/arangodb/kube-arangodb/pkg/util/http"
 	"github.com/arangodb/kube-arangodb/pkg/util/k8sutil"
 )
 
@@ -61,58 +60,21 @@ func WithRequireAuthentication(ctx context.Context) context.Context {
 	return context.WithValue(ctx, requireAuthenticationKey{}, true)
 }
 
-var (
-	sharedHTTPTransport = &nhttp.Transport{
-		Proxy: nhttp.ProxyFromEnvironment,
-		DialContext: (&net.Dialer{
-			Timeout:   30 * time.Second,
-			KeepAlive: 90 * time.Second,
-			DualStack: true,
-		}).DialContext,
-		MaxIdleConns:          100,
-		IdleConnTimeout:       90 * time.Second,
-		TLSHandshakeTimeout:   10 * time.Second,
-		ExpectContinueTimeout: 1 * time.Second,
+func sharedHTTPTransport() nhttp.RoundTripper {
+	return operatorHTTP.Transport()
 }
-	sharedHTTPSTransport = &nhttp.Transport{
-		Proxy: nhttp.ProxyFromEnvironment,
-		DialContext: (&net.Dialer{
-			Timeout:   30 * time.Second,
-			KeepAlive: 90 * time.Second,
-			DualStack: true,
-		}).DialContext,
-		MaxIdleConns:          100,
-		IdleConnTimeout:       90 * time.Second,
-		TLSHandshakeTimeout:   10 * time.Second,
-		ExpectContinueTimeout: 1 * time.Second,
-		TLSClientConfig:       &tls.Config{InsecureSkipVerify: true},
+
+func sharedHTTPSTransport() nhttp.RoundTripper {
+	return operatorHTTP.Transport(operatorHTTP.WithTransportTLS(operatorHTTP.Insecure))
 }
-	sharedHTTPTransportShortTimeout = &nhttp.Transport{
-		Proxy: nhttp.ProxyFromEnvironment,
-		DialContext: (&net.Dialer{
-			Timeout:   30 * time.Second,
-			KeepAlive: 100 * time.Millisecond,
-			DualStack: true,
-		}).DialContext,
-		MaxIdleConns:          100,
-		IdleConnTimeout:       100 * time.Millisecond,
-		TLSHandshakeTimeout:   10 * time.Second,
-		ExpectContinueTimeout: 1 * time.Second,
+
+func sharedHTTPTransportShortTimeout() nhttp.RoundTripper {
+	return operatorHTTP.RoundTripperWithShortTransport()
 }
-	sharedHTTPSTransportShortTimeout = &nhttp.Transport{
-		Proxy: nhttp.ProxyFromEnvironment,
-		DialContext: (&net.Dialer{
-			Timeout:   30 * time.Second,
-			KeepAlive: 100 * time.Millisecond,
-			DualStack: true,
-		}).DialContext,
-		MaxIdleConns:          100,
-		IdleConnTimeout:       100 * time.Millisecond,
-		TLSHandshakeTimeout:   10 * time.Second,
-		ExpectContinueTimeout: 1 * time.Second,
-		TLSClientConfig:       &tls.Config{InsecureSkipVerify: true},
+
+func sharedHTTPSTransportShortTimeout() nhttp.RoundTripper {
+	return operatorHTTP.RoundTripperWithShortTransport(operatorHTTP.WithTransportTLS(operatorHTTP.Insecure))
 }
-)
 
 // CreateArangodClient creates a go-driver client for a specific member in the given group.
 func CreateArangodClient(ctx context.Context, cli typedCore.CoreV1Interface, apiObject *api.ArangoDeployment, group api.ServerGroup, id string, asyncSupport bool) (driver.Client, error) {
@@ -192,7 +154,7 @@ func createArangodHTTPConfigForDNSNames(apiObject *api.ArangoDeployment, dnsName
 		}
 	}
 	connConfig := http.ConnectionConfig{
-		Transport:          transport,
+		Transport:          transport(),
 		DontFollowRedirect: true,
 	}
 	for _, dnsName := range dnsNames {

pkg/util/http/client.go

@@ -0,0 +1,53 @@
+//
+// DISCLAIMER
+//
+// Copyright 2024 ArangoDB GmbH, Cologne, Germany
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+
+package http
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"net/http"
+)
+
+func RoundTripper(mods ...TransportMod) http.RoundTripper {
+	df := append([]TransportMod{
+		configuration.DefaultTransport,
+	}, mods...)
+
+	return Transport(df...)
+}
+
+func RoundTripperWithShortTransport(mods ...TransportMod) http.RoundTripper {
+	df := append([]TransportMod{
+		configuration.ShortTransport,
+	}, mods...)
+
+	return Transport(df...)
+}
+
+func Insecure(in *tls.Config) {
+	in.InsecureSkipVerify = true
+}
+
+func WithRootCA(ca *x509.CertPool) TransportTLSMod {
+	return func(in *tls.Config) {
+		in.RootCAs = ca
+	}
+}

pkg/util/http/client_configuration.go

@@ -0,0 +1,140 @@
+//
+// DISCLAIMER
+//
+// Copyright 2024 ArangoDB GmbH, Cologne, Germany
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+
+package http
+
+import (
+	"net"
+	"net/http"
+	"time"
+
+	"github.com/spf13/cobra"
+)
+
+func InitConfiguration(cmd *cobra.Command) error {
+	return configuration.Init(cmd)
+}
+
+const (
+	defaultTransportKeepAlive         bool = true
+	defaultTransportForceAttemptHTTP2 bool = false
+
+	defaultTransportMaxIdleConns int = 100
+
+	defaultTransportDialTimeout           = 30 * time.Second
+	defaultTransportKeepAliveTimeout      = 90 * time.Second
+	defaultTransportKeepAliveTimeoutShort = 100 * time.Millisecond
+	defaultTransportIdleConnTimeout       = 90 * time.Second
+	defaultTransportIdleConnTimeoutShort  = 100 * time.Millisecond
+	defaultTransportTLSHandshakeTimeout   = 10 * time.Second
+	defaultTransportExpectContinueTimeout = 1 * time.Second
+)
+
+var configuration = configurationObject{
+	TransportKeepAlive:             defaultTransportKeepAlive,
+	TransportForceAttemptHTTP2:     defaultTransportForceAttemptHTTP2,
+	TransportMaxIdleConns:          defaultTransportMaxIdleConns,
+	TransportDialTimeout:           defaultTransportDialTimeout,
+	TransportKeepAliveTimeout:      defaultTransportKeepAliveTimeout,
+	TransportKeepAliveTimeoutShort: defaultTransportKeepAliveTimeoutShort,
+	TransportIdleConnTimeout:       defaultTransportIdleConnTimeout,
+	TransportIdleConnTimeoutShort:  defaultTransportIdleConnTimeoutShort,
+	TransportTLSHandshakeTimeout:   defaultTransportTLSHandshakeTimeout,
+	TransportExpectContinueTimeout: defaultTransportExpectContinueTimeout,
+}
+
+type configurationObject struct {
+	TransportKeepAlive         bool
+	TransportForceAttemptHTTP2 bool
+
+	TransportMaxIdleConns int
+
+	TransportDialTimeout           time.Duration
+	TransportKeepAliveTimeout      time.Duration
+	TransportKeepAliveTimeoutShort time.Duration
+	TransportIdleConnTimeout       time.Duration
+	TransportIdleConnTimeoutShort  time.Duration
+	TransportTLSHandshakeTimeout   time.Duration
+	TransportExpectContinueTimeout time.Duration
+}
+
+func (c *configurationObject) Init(cmd *cobra.Command) error {
+	if c == nil {
+		return nil
+	}
+
+	f := cmd.PersistentFlags()
+
+	f.BoolVar(&configuration.TransportKeepAlive, "http1.keep-alive", defaultTransportKeepAlive, "If false, disables HTTP keep-alives and will only use the connection to the server for a single HTTP request")
+	f.BoolVar(&configuration.TransportForceAttemptHTTP2, "http1.force-attempt-http2", defaultTransportForceAttemptHTTP2, "controls whether HTTP/2 is enabled")
+
+	f.IntVar(&configuration.TransportMaxIdleConns, "http1.transport.max-idle-conns", defaultTransportMaxIdleConns, "Maximum number of idle (keep-alive) connections across all hosts. Zero means no limit")
+
+	f.DurationVar(&configuration.TransportDialTimeout, "http1.transport.dial-timeout", defaultTransportDialTimeout, "Maximum amount of time a dial will wait for a connect to complete")
+	f.DurationVar(&configuration.TransportKeepAliveTimeout, "http1.transport.keep-alive-timeout", defaultTransportKeepAliveTimeout, "Interval between keep-alive probes for an active network connection")
+	f.DurationVar(&configuration.TransportKeepAliveTimeoutShort, "http1.transport.keep-alive-timeout-short", defaultTransportKeepAliveTimeoutShort, "Interval between keep-alive probes for an active network connection")
+
+	f.DurationVar(&configuration.TransportIdleConnTimeout, "http1.transport.idle-conn-timeout", defaultTransportIdleConnTimeout, "Maximum amount of time an idle (keep-alive) connection will remain idle before closing itself. Zero means no limit")
+	f.DurationVar(&configuration.TransportIdleConnTimeoutShort, "http1.transport.idle-conn-timeout-short", defaultTransportIdleConnTimeoutShort, "Maximum amount of time an idle (keep-alive) connection will remain idle before closing itself. Zero means no limit")
+	f.DurationVar(&configuration.TransportTLSHandshakeTimeout, "http1.transport.tls-handshake-timeout", defaultTransportTLSHandshakeTimeout, "Maximum amount of time to wait for a TLS handshake. Zero means no timeout")
+	f.DurationVar(&configuration.TransportExpectContinueTimeout, "http1.transport.except-continue-timeout", defaultTransportExpectContinueTimeout, "")
+
+	if err := f.MarkHidden("http1.transport.except-continue-timeout"); err != nil {
+		return err
+	}
+
+	if err := f.MarkHidden("http1.force-attempt-http2"); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *configurationObject) DefaultTransport(in *http.Transport) {
+	if c == nil {
+		return
+	}
+	in.Proxy = http.ProxyFromEnvironment
+	in.ForceAttemptHTTP2 = c.TransportForceAttemptHTTP2
+	in.DialContext = (&net.Dialer{
+		Timeout:   c.TransportDialTimeout,
+		KeepAlive: c.TransportKeepAliveTimeout,
+		DualStack: true,
+	}).DialContext
+
+	in.MaxIdleConns = c.TransportMaxIdleConns
+	in.IdleConnTimeout = c.TransportIdleConnTimeout
+	in.TLSHandshakeTimeout = c.TransportTLSHandshakeTimeout
+	in.ExpectContinueTimeout = c.TransportExpectContinueTimeout
+	in.DisableKeepAlives = !c.TransportKeepAlive
+}
+
+func (c *configurationObject) ShortTransport(in *http.Transport) {
+	if c == nil {
+		return
+	}
+	in.DialContext = (&net.Dialer{
+		Timeout:   c.TransportDialTimeout,
+		KeepAlive: c.TransportKeepAliveTimeoutShort,
+		DualStack: true,
+	}).DialContext
+
+	in.IdleConnTimeout = c.TransportIdleConnTimeoutShort
+}

pkg/util/http/client_mod.go

@@ -0,0 +1,57 @@
+//
+// DISCLAIMER
+//
+// Copyright 2024 ArangoDB GmbH, Cologne, Germany
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Copyright holder is ArangoDB GmbH, Cologne, Germany
+//
+
+package http
+
+import (
+	"crypto/tls"
+	"net/http"
+)
+
+type Mod[T any] func(in T)
+
+type TransportMod Mod[*http.Transport]
+
+type TransportTLSMod Mod[*tls.Config]
+
+func Transport(mods ...TransportMod) http.RoundTripper {
+	var c http.Transport
+
+	for _, m := range mods {
+		if m == nil {
+			continue
+		}
+		m(&c)
+	}
+
+	return &c
+}
+
+func WithTransportTLS(mods ...TransportTLSMod) TransportMod {
+	return func(in *http.Transport) {
+		if in.TLSClientConfig == nil {
+			in.TLSClientConfig = &tls.Config{}
+		}
+
+		for _, mod := range mods {
+			mod(in.TLSClientConfig)
+		}
+	}
+}