FFM-11006 Add Connection close header

.harness/ffgolangserversdk.yaml

@@ -36,7 +36,7 @@ pipeline:
                   identifier: Submodule_Init
                   spec:
                     connectorRef: DockerHub
-                    image: golang:1.18.6
+                    image: golang:1.19.9
                     shell: Sh
                     command: "mkdir -p ~/.ssh\nssh-keyscan -t rsa github.com >> ~/.ssh/known_hosts\n\ncat <<EOF >> .gitmodules\n[submodule \"tests/ff-test-cases\"]\n\tpath = tests/ff-test-cases\n\turl = https://github.com/drone/ff-test-cases.git\nEOF\n\ngit submodule update --init --recursive"
               - parallel:
@@ -46,7 +46,7 @@ pipeline:
                       identifier: Build_and_Test
                       spec:
                         connectorRef: DockerHub
-                        image: golang:1.18.6
+                        image: golang:1.19.9
                         shell: Sh
                         command: |-
                           go install github.com/jstemmer/go-junit-report@latest

client/client.go

@@ -5,16 +5,17 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"github.com/cenkalti/backoff/v4"
-	"github.com/harness/ff-golang-server-sdk/sdk_codes"
-	"golang.org/x/sync/errgroup"
 	"log"
 	"net/http"
 	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
 
+	"github.com/cenkalti/backoff/v4"
+	"github.com/harness/ff-golang-server-sdk/sdk_codes"
+	"golang.org/x/sync/errgroup"
+
 	"github.com/harness/ff-golang-server-sdk/evaluation"
 	"github.com/harness/ff-golang-server-sdk/logger"
 
@@ -393,14 +394,20 @@ func (c *CfClient) authenticate(ctx context.Context) error {
 	// Use a custom transport which adds headers for tracking usage
 	// The `WithRequestEditorFn` cannot be used for SSE requests, so we need to provide a custom transport to the
 	// http client so that these headers can be added to all requests.
-	getHeadersFn := func() (map[string]string, error) {
-		return map[string]string{
+	getHeadersFn := func(r *http.Request) (map[string]string, error) {
+		headers := map[string]string{
 			"User-Agent":            "GoSDK/" + analyticsservice.SdkVersion,
 			"Harness-SDK-Info":      fmt.Sprintf("Go %s Server", analyticsservice.SdkVersion),
 			"Harness-EnvironmentID": c.environmentID,
-		}, nil
+		}
+
+		if strings.Contains(r.URL.Path, "/metrics") && r.Method == http.MethodPost {
+			headers["Connection"] = "close"
+		}
+
+		return headers, nil
 	}
-	
+
 	// Wrap the httpClient's transport with our own custom transport, which currently just adds extra headers
 	// for analytics purposes.
 	// If the httpClient doesn't have a Transport we can honour, then just use a default transport.

client/transport.go

@@ -3,7 +3,7 @@ package client
 import "net/http"
 
 // HeadersFn is a function type that provides headers dynamically.
-type HeadersFn func() (map[string]string, error)
+type HeadersFn func(r *http.Request) (map[string]string, error)
 
 // customTransport wraps an http.RoundTripper and allows adding headers dynamically. This means we can still use
 // the goretryable-http client's transport, or a user's transport if they've provided their own http client.
@@ -22,7 +22,7 @@ func NewCustomTransport(baseTransport http.RoundTripper, getHeaderFn HeadersFn)
 
 func (t *customTransport) RoundTrip(req *http.Request) (*http.Response, error) {
 	// Retrieve the headers using the provided function.
-	headers, err := t.getHeaders()
+	headers, err := t.getHeaders(req)
 	if err != nil {
 		return nil, err
 	}