Use WithUserAgent

Signed-off-by: Julien Pivotto <roidelapluie@o11y.eu>

config/http_config.go

@@ -224,8 +224,6 @@ type OAuth2 struct {
 	ProxyURL URL `yaml:"proxy_url,omitempty" json:"proxy_url,omitempty"`
 	// TLSConfig is used to connect to the token URL.
 	TLSConfig TLSConfig `yaml:"tls_config,omitempty"`
-	// UserAgent is used to set a custom User-Agent http header while making the oauth request.
-	UserAgent string `yaml:"user_agent,omitempty" json:"user_agent,omitempty"`
 }
 
 // SetDirectory joins any relative file paths with dir.
@@ -374,6 +372,7 @@ type httpClientOptions struct {
 	keepAlivesEnabled bool
 	http2Enabled      bool
 	idleConnTimeout   time.Duration
+	userAgent         string
 }
 
 // HTTPClientOption defines an option that can be applied to the HTTP client.
@@ -407,6 +406,13 @@ func WithIdleConnTimeout(timeout time.Duration) HTTPClientOption {
 	}
 }
 
+// WithIdleConnTimeout allows setting the user agent.
+func WithUserAgent(ua string) HTTPClientOption {
+	return func(opts *httpClientOptions) {
+		opts.userAgent = ua
+	}
+}
+
 // NewClient returns a http.Client using the specified http.RoundTripper.
 func newClient(rt http.RoundTripper) *http.Client {
 	return &http.Client{Transport: rt}
@@ -499,8 +505,12 @@ func NewRoundTripperFromConfig(cfg HTTPClientConfig, name string, optFuncs ...HT
 			rt = NewBasicAuthRoundTripper(cfg.BasicAuth.Username, cfg.BasicAuth.Password, cfg.BasicAuth.PasswordFile, rt)
 		}
 
+		if opts.userAgent != "" {
+			rt = NewUserAgentRoundTripper(opts.userAgent, rt)
+		}
+
 		if cfg.OAuth2 != nil {
-			rt = NewOAuth2RoundTripper(cfg.OAuth2, rt)
+			rt = NewOAuth2RoundTripper(cfg.OAuth2, rt, &opts)
 		}
 		// Return a new configured RoundTripper.
 		return rt, nil
@@ -621,12 +631,14 @@ type oauth2RoundTripper struct {
 	next   http.RoundTripper
 	secret string
 	mtx    sync.RWMutex
+	opts   *httpClientOptions
 }
 
-func NewOAuth2RoundTripper(config *OAuth2, next http.RoundTripper) http.RoundTripper {
+func NewOAuth2RoundTripper(config *OAuth2, next http.RoundTripper, opts *httpClientOptions) http.RoundTripper {
 	return &oauth2RoundTripper{
 		config: config,
 		next:   next,
+		opts:   opts,
 	}
 }
 
@@ -683,8 +695,8 @@ func (rt *oauth2RoundTripper) RoundTrip(req *http.Request) (*http.Response, erro
 			}
 		}
 
-		if rt.config.UserAgent != "" {
-			t = NewUserAgentRoundTripper(rt.config.UserAgent, t)
+		if rt.opts.userAgent != "" {
+			t = NewUserAgentRoundTripper(rt.opts.userAgent, t)
 		}
 
 		ctx := context.WithValue(context.Background(), oauth2.HTTPClient, &http.Client{Transport: t})

config/http_config_test.go

@@ -1183,12 +1183,6 @@ type oauth2TestServerResponse struct {
 
 func TestOAuth2(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.URL.Path == "/token" {
-			if r.Header.Get("User-Agent") != "myuseragent" {
-				t.Fatalf("Expected User-Agent header in oauth request to be 'myuseragent', got '%s'", r.Header.Get("User-Agent"))
-			}
-		}
-
 		res, _ := json.Marshal(oauth2TestServerResponse{
 			AccessToken: "12345",
 			TokenType:   "Bearer",
@@ -1205,7 +1199,6 @@ scopes:
  - A
  - B
 token_url: %s/token
-user_agent: myuseragent
 endpoint_params:
  hi: hello
 `, ts.URL)
@@ -1215,7 +1208,6 @@ endpoint_params:
 		Scopes:         []string{"A", "B"},
 		EndpointParams: map[string]string{"hi": "hello"},
 		TokenURL:       fmt.Sprintf("%s/token", ts.URL),
-		UserAgent:      "myuseragent",
 	}
 
 	var unmarshalledConfig OAuth2
@@ -1227,7 +1219,7 @@ endpoint_params:
 		t.Fatalf("Got unmarshalled config %v, expected %v", unmarshalledConfig, expectedConfig)
 	}
 
-	rt := NewOAuth2RoundTripper(&expectedConfig, http.DefaultTransport)
+	rt := NewOAuth2RoundTripper(&expectedConfig, http.DefaultTransport, &defaultHTTPClientOptions)
 
 	client := http.Client{
 		Transport: rt,
@@ -1240,6 +1232,50 @@ endpoint_params:
 	}
 }
 
+func TestOAuth2UserAgent(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/" {
+			if r.Header.Get("User-Agent") != "myuseragent" {
+				t.Fatalf("Expected User-Agent header in oauth request to be 'myuseragent', got '%s'", r.Header.Get("User-Agent"))
+			}
+		}
+
+		res, _ := json.Marshal(oauth2TestServerResponse{
+			AccessToken: "12345",
+			TokenType:   "Bearer",
+		})
+		w.Header().Add("Content-Type", "application/json")
+		_, _ = w.Write(res)
+	}))
+	defer ts.Close()
+
+	config := &OAuth2{
+		ClientID:       "1",
+		ClientSecret:   "2",
+		Scopes:         []string{"A", "B"},
+		EndpointParams: map[string]string{"hi": "hello"},
+		TokenURL:       fmt.Sprintf("%s/token", ts.URL),
+	}
+
+	opts := defaultHTTPClientOptions
+	WithUserAgent("myuseragent")(&opts)
+
+	rt := NewOAuth2RoundTripper(config, http.DefaultTransport, &opts)
+
+	client := http.Client{
+		Transport: rt,
+	}
+	resp, err := client.Get(ts.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	authorization := resp.Request.Header.Get("Authorization")
+	if authorization != "Bearer 12345" {
+		t.Fatalf("Expected authorization header to be 'Bearer 12345', got '%s'", authorization)
+	}
+}
+
 func TestOAuth2WithFile(t *testing.T) {
 	var expectedAuth *string
 	var previousAuth string
@@ -1302,7 +1338,7 @@ endpoint_params:
 		t.Fatalf("Got unmarshalled config %v, expected %v", unmarshalledConfig, expectedConfig)
 	}
 
-	rt := NewOAuth2RoundTripper(&expectedConfig, http.DefaultTransport)
+	rt := NewOAuth2RoundTripper(&expectedConfig, http.DefaultTransport, &defaultHTTPClientOptions)
 
 	client := http.Client{
 		Transport: rt,
@@ -1496,10 +1532,3 @@ func TestOAuth2Proxy(t *testing.T) {
 		t.Errorf("Error loading OAuth2 client config: %v", err)
 	}
 }
-
-func TestOAuth2UserAgent(t *testing.T) {
-	_, _, err := LoadHTTPConfigFile("testdata/http.conf.oauth2-user-agent.good.yml")
-	if err != nil {
-		t.Errorf("Error loading OAuth2 client config: %v", err)
-	}
-}