feat(flipt): add WithHTTPClient option for custom HTTP client configuration

Add WithHTTPClient option to both provider and transport layers to allow
users to configure custom HTTP clients. This enables use cases like custom
timeouts, proxies, or other HTTP client customizations. The option defaults
to http.DefaultClient when not specified.

Signed-off-by: Roman Dmytrenko <[email protected]>

Author: erka

providers/flipt/go.sum

@@ -19,8 +19,6 @@ github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/open-feature/go-sdk v1.15.1 h1:TC3FtHtOKlGlIbSf3SEpxXVhgTd/bCbuc39XHIyltkw=
-github.com/open-feature/go-sdk v1.15.1/go.mod h1:2WAFYzt8rLYavcubpCoiym3iSCXiHdPB6DxtMkv2wyo=
 github.com/open-feature/go-sdk v1.16.0 h1:5NCHYv5slvNBIZhYXAzAufo0OI59OACZ5tczVqSE+Tg=
 github.com/open-feature/go-sdk v1.16.0/go.mod h1:EIF40QcoYT1VbQkMPy2ZJH4kvZeY+qGUXAorzSWgKSo=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
@@ -51,16 +49,12 @@ go.opentelemetry.io/otel/sdk/metric v1.33.0 h1:Gs5VK9/WUJhNXZgn8MR6ITatvAmKeIuCt
 go.opentelemetry.io/otel/sdk/metric v1.33.0/go.mod h1:dL5ykHZmm1B1nVRk9dDjChwDmt81MjVp3gLkQRwKf/Q=
 go.opentelemetry.io/otel/trace v1.33.0 h1:cCJuF7LRjUFso9LPnEAHJDB2pqzp+hbO8eu1qqW2d/s=
 go.opentelemetry.io/otel/trace v1.33.0/go.mod h1:uIcdVUZMpTAmz0tI1z04GoVSezK37CbGV4fr1f2nBck=
-go.uber.org/mock v0.5.2 h1:LbtPTcP8A5k9WPXj54PPPbjcI4Y6lhyOZXn+VS7wNko=
-go.uber.org/mock v0.5.2/go.mod h1:wLlUxC2vVTPTaE3UD51E0BGOAElKrILxhVSDYQLld5o=
 go.uber.org/mock v0.6.0 h1:hyF9dfmbgIX5EfOdasqLsWD6xqpNZlXblLB/Dbnwv3Y=
 go.uber.org/mock v0.6.0/go.mod h1:KiVJ4BqZJaMj4svdfmHM0AUx4NJYO8ZNpPnZn1Z+BBU=
 golang.org/x/net v0.38.0 h1:vRMAPTMaeGqVhG5QyLJHqNDwecKTomGeqbnfZyKlBI8=
 golang.org/x/net v0.38.0/go.mod h1:ivrbrMbzFq5J41QOQh0siUuly180yBYtLp+CKbEaFx8=
 golang.org/x/sys v0.31.0 h1:ioabZlmFYtWhL+TRYpcnNlLwhyxaM9kWTDEmfnprqik=
 golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/text v0.26.0 h1:P42AVeLghgTYr4+xUnTRKDMqpar+PtX7KWuNQL21L8M=
-golang.org/x/text v0.26.0/go.mod h1:QK15LZJUUQVJxhz7wXgxSy/CJaTFjd0G+YLonydOVQA=
 golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
 golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=
 google.golang.org/genproto/googleapis/api v0.0.0-20241230172942-26aa7a208def h1:0Km0hi+g2KXbXL0+riZzSCKz23f4MmwicuEb00JeonI=

providers/flipt/pkg/provider/provider.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net/http"
 	"strconv"
 
 	"github.com/open-feature/go-sdk-contrib/providers/flipt/pkg/service/transport"
@@ -25,11 +26,19 @@ type Config struct {
 	TokenProvider   sdk.ClientTokenProvider
 	Namespace       string
 	GRPCDialOptions []grpc.DialOption
+	httpClient      *http.Client
 }
 
 // Option is a configuration option for the provider.
 type Option func(*Provider)
 
+// WithHTTPClient returns an [Option] that specifies the HTTP client to use as the basis of communications.
+func WithHTTPClient(client *http.Client) Option {
+	return func(p *Provider) {
+		p.config.httpClient = client
+	}
+}
+
 // WithAddress sets the address for the remote Flipt gRPC or HTTP API.
 func WithAddress(address string) Option {
 	return func(p *Provider) {
@@ -86,14 +95,19 @@ func NewProvider(opts ...Option) *Provider {
 		Address:         "http://localhost:8080",
 		Namespace:       "default",
 		GRPCDialOptions: []grpc.DialOption{},
+		httpClient:      http.DefaultClient,
 	}}
 
 	for _, opt := range opts {
 		opt(p)
 	}
 
 	if p.svc == nil {
-		topts := []transport.Option{transport.WithAddress(p.config.Address), transport.WithCertificatePath(p.config.CertificatePath)}
+		topts := []transport.Option{
+			transport.WithAddress(p.config.Address),
+			transport.WithHTTPClient(p.config.httpClient),
+			transport.WithCertificatePath(p.config.CertificatePath),
+		}
 		if p.config.TokenProvider != nil {
 			topts = append(topts, transport.WithClientTokenProvider(p.config.TokenProvider))
 		}

providers/flipt/pkg/provider/provider_test.go

@@ -3,6 +3,7 @@ package flipt
 import (
 	"encoding/json"
 	"errors"
+	"net/http"
 	"testing"
 
 	of "github.com/open-feature/go-sdk/openfeature"
@@ -672,3 +673,9 @@ func TestObjectEvaluation(t *testing.T) {
 		})
 	}
 }
+
+func TestWithHTTPClientOption(t *testing.T) {
+	client := &http.Client{}
+	p := NewProvider(WithHTTPClient(client))
+	assert.Equal(t, client, p.config.httpClient)
+}

providers/flipt/pkg/service/transport/service.go

@@ -6,6 +6,7 @@ import (
 	"crypto/x509"
 	"errors"
 	"fmt"
+	"net/http"
 	"net/url"
 	"os"
 	"strings"
@@ -40,11 +41,19 @@ type Service struct {
 	once              sync.Once
 	tokenProvider     sdk.ClientTokenProvider
 	grpcDialOptions   []grpc.DialOption
+	httpClient        *http.Client
 }
 
 // Option is a service option.
 type Option func(*Service)
 
+// WithHTTPClient returns an [Option] that specifies the HTTP client to use as the basis of communications.
+func WithHTTPClient(client *http.Client) Option {
+	return func(s *Service) {
+		s.httpClient = client
+	}
+}
+
 // WithAddress sets the address for the remote Flipt gRPC API.
 func WithAddress(address string) Option {
 	return func(s *Service) {
@@ -91,6 +100,7 @@ func New(opts ...Option) *Service {
 		grpcDialOptions: []grpc.DialOption{
 			grpc.WithStatsHandler(otelgrpc.NewClientHandler()),
 		},
+		httpClient: http.DefaultClient,
 	}
 
 	for _, opt := range opts {
@@ -158,7 +168,7 @@ func (s *Service) instance() (offlipt.Client, error) {
 			opts = append(opts, sdk.WithClientTokenProvider(s.tokenProvider))
 		}
 
-		hclient := sdk.New(sdkhttp.NewTransport(s.address), opts...)
+		hclient := sdk.New(sdkhttp.NewTransport(s.address, sdkhttp.WithHTTPClient(s.httpClient)), opts...)
 		if u.Scheme == "https" || u.Scheme == "http" {
 			s.client = &fclient{
 				hclient.Flipt(),

providers/flipt/pkg/service/transport/service_test.go

@@ -1,6 +1,7 @@
 package transport
 
 import (
+	"net/http"
 	"testing"
 
 	of "github.com/open-feature/go-sdk/openfeature"
@@ -288,3 +289,9 @@ func TestGRPCToOpenFeatureError(t *testing.T) {
 		})
 	}
 }
+
+func TestWithHTTPClientOption(t *testing.T) {
+	client := &http.Client{}
+	p := New(WithHTTPClient(client))
+	assert.Equal(t, client, p.httpClient)
+}