client: Allow User-Agent header to be overriddenzj-override-user-agent

The user agent for requests to the internal API endpoints used the
default Go provided user agent. This change updates that to always set
something else, by default `GitLab-Shell`.

Than for others importing the package, there's a new API to set it to
something else. This has been done with new method, a setter, to
maintain backwards compatibility in the API.

2 files changed, 43 insertions, 2 deletions

diff --git a/client/gitlabnet.go b/client/gitlabnet.go
index b908d04..fcefb24 100644
--- a/client/gitlabnet.go
+++ b/client/gitlabnet.go
@@ -19,6 +19,7 @@ import (
 const (
 	internalApiPath  = "/api/v4/internal"
 	secretHeaderName = "Gitlab-Shared-Secret"
+	defaultUserAgent = "GitLab-Shell"
 )
 
 type ErrorResponse struct {
@@ -26,8 +27,11 @@ type ErrorResponse struct {
 }
 
 type GitlabNetClient struct {
-	httpClient             *HttpClient
-	user, password, secret string
+	httpClient *HttpClient
+	user       string
+	password   string
+	secret     string
+	userAgent  string
 }
 
 func NewGitlabNetClient(
@@ -46,9 +50,16 @@ func NewGitlabNetClient(
 		user:       user,
 		password:   password,
 		secret:     secret,
+		userAgent:  defaultUserAgent,
 	}, nil
 }
 
+// SetUserAgent overrides the default user agent for the User-Agent header field
+// for subsequent requests for the GitlabNetClient
+func (c *GitlabNetClient) SetUserAgent(ua string) {
+	c.userAgent = ua
+}
+
 func normalizePath(path string) string {
 	if !strings.HasPrefix(path, "/") {
 		path = "/" + path
@@ -119,6 +130,7 @@ func (c *GitlabNetClient) DoRequest(ctx context.Context, method, path string, da
 	request.Header.Set(secretHeaderName, encodedSecret)
 
 	request.Header.Add("Content-Type", "application/json")
+	request.Header.Add("User-Agent", c.userAgent)
 	request.Close = true
 
 	start := time.Now()
diff --git a/client/httpclient_test.go b/client/httpclient_test.go
index 97e1384..59dabc4 100644
--- a/client/httpclient_test.go
+++ b/client/httpclient_test.go
@@ -94,6 +94,35 @@ func TestEmptyBasicAuthSettings(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestRequestWithUserAgent(t *testing.T) {
+	const gitalyUserAgent = "gitaly/13.5.0"
+	requests := []testserver.TestRequestHandler{
+		{
+			Path: "/api/v4/internal/default_user_agent",
+			Handler: func(w http.ResponseWriter, r *http.Request) {
+				assert.Equal(t, defaultUserAgent, r.UserAgent())
+			},
+		},
+		{
+			Path: "/api/v4/internal/override_user_agent",
+			Handler: func(w http.ResponseWriter, r *http.Request) {
+				assert.Equal(t, gitalyUserAgent, r.UserAgent())
+			},
+		},
+	}
+
+	client, cleanup := setup(t, "", "", requests)
+	defer cleanup()
+
+	_, err := client.Get(context.Background(), "/default_user_agent")
+	require.NoError(t, err)
+
+	client.SetUserAgent(gitalyUserAgent)
+	_, err = client.Get(context.Background(), "/override_user_agent")
+	require.NoError(t, err)
+
+}
+
 func setup(t *testing.T, username, password string, requests []testserver.TestRequestHandler) (*GitlabNetClient, func()) {
 	url, cleanup := testserver.StartHttpServer(t, requests)