Use upstream parameter follow_redirects

Signed-off-by: Julien Pivotto <[email protected]>

CHANGELOG.md

@@ -3,6 +3,11 @@
 This release is built with go 1.16.4, which contains a [bugfix](https://github.com/golang/go/issues/45712)
 that can cause an untrusted target to make Blackbox Exporter crash.
 
+In the HTTP probe, `no_follow_redirect` has been changed to `follow_redirect`.
+This release accepts both, with a precedence to the `no_follow_redirect` parameter.
+In the next release, `no_follow_redirect` will be removed.
+
+* [CHANGE] HTTP proble: no_follow_redirect has been renamed to follow_redirect.
 * [FEATURE] Add support for decompression of HTTP responses. #764
 * [FEATURE] Enable TLS and basic authentication. #784
 * [FEATURE] HTTP probe: *experimental* OAuth2 support.

CONFIGURATION.md

@@ -62,7 +62,7 @@ The other placeholders are specified separately.
   [ compression: <string> | default = "" ]
 
   # Whether or not the probe will follow any redirects.
-  [ no_follow_redirects: <boolean> | default = false ]
+  [ follow_redirects: <boolean> | default = true ]
 
   # Probe fails if SSL is present.
   [ fail_if_ssl: <boolean> | default = false ]

config/config.go

@@ -57,6 +57,7 @@ var (
 	// DefaultHTTPProbe set default value for HTTPProbe
 	DefaultHTTPProbe = HTTPProbe{
 		IPProtocolFallback: true,
+		HTTPClientConfig:   config.DefaultHTTPClientConfig,
 	}
 
 	// DefaultTCPProbe set default value for TCPProbe
@@ -181,7 +182,7 @@ type HTTPProbe struct {
 	ValidHTTPVersions            []string                `yaml:"valid_http_versions,omitempty"`
 	IPProtocol                   string                  `yaml:"preferred_ip_protocol,omitempty"`
 	IPProtocolFallback           bool                    `yaml:"ip_protocol_fallback,omitempty"`
-	NoFollowRedirects            bool                    `yaml:"no_follow_redirects,omitempty"`
+	NoFollowRedirects            *bool                   `yaml:"no_follow_redirects,omitempty"`
 	FailIfSSL                    bool                    `yaml:"fail_if_ssl,omitempty"`
 	FailIfNotSSL                 bool                    `yaml:"fail_if_not_ssl,omitempty"`
 	Method                       string                  `yaml:"method,omitempty"`
@@ -277,6 +278,10 @@ func (s *HTTPProbe) UnmarshalYAML(unmarshal func(interface{}) error) error {
 		return err
 	}
 
+	if s.NoFollowRedirects != nil {
+		s.HTTPClientConfig.FollowRedirects = !*s.NoFollowRedirects
+	}
+
 	for key, value := range s.Headers {
 		switch strings.Title(key) {
 		case "Accept-Encoding":

prober/http.go

@@ -373,7 +373,7 @@ func ProbeHTTP(ctx context.Context, target string, module config.Module, registr
 	client.CheckRedirect = func(r *http.Request, via []*http.Request) error {
 		level.Info(logger).Log("msg", "Received redirect", "location", r.Response.Header.Get("Location"))
 		redirects = len(via)
-		if redirects > 10 || httpConfig.NoFollowRedirects {
+		if redirects > 10 || !httpConfig.HTTPClientConfig.FollowRedirects {
 			level.Info(logger).Log("msg", "Not following redirect")
 			return errors.New("don't follow redirects")
 		}

prober/http_test.go

@@ -526,7 +526,7 @@ func TestRedirectFollowed(t *testing.T) {
 	registry := prometheus.NewRegistry()
 	testCTX, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
-	result := ProbeHTTP(testCTX, ts.URL, config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true}}, registry, log.NewNopLogger())
+	result := ProbeHTTP(testCTX, ts.URL, config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true, HTTPClientConfig: pconfig.DefaultHTTPClientConfig}}, registry, log.NewNopLogger())
 	body := recorder.Body.String()
 	if !result {
 		t.Fatalf("Redirect test failed unexpectedly, got %s", body)
@@ -554,7 +554,7 @@ func TestRedirectNotFollowed(t *testing.T) {
 	testCTX, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
 	result := ProbeHTTP(testCTX, ts.URL,
-		config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true, NoFollowRedirects: true, ValidStatusCodes: []int{302}}}, registry, log.NewNopLogger())
+		config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true, HTTPClientConfig: pconfig.HTTPClientConfig{FollowRedirects: false}, ValidStatusCodes: []int{302}}}, registry, log.NewNopLogger())
 	body := recorder.Body.String()
 	if !result {
 		t.Fatalf("Redirect test failed unexpectedly, got %s", body)
@@ -601,7 +601,7 @@ func TestRedirectionLimit(t *testing.T) {
 	result := ProbeHTTP(
 		testCTX,
 		ts.URL,
-		config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true}},
+		config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true, HTTPClientConfig: pconfig.DefaultHTTPClientConfig}},
 		registry,
 		log.NewNopLogger())
 	if result {
@@ -1136,7 +1136,7 @@ func TestRedirectToTLSHostWorks(t *testing.T) {
 	testCTX, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
 	result := ProbeHTTP(testCTX, ts.URL,
-		config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true}}, registry, log.NewNopLogger())
+		config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true, HTTPClientConfig: pconfig.DefaultHTTPClientConfig}}, registry, log.NewNopLogger())
 	if !result {
 		t.Fatalf("Redirect test failed unexpectedly")
 	}
@@ -1209,7 +1209,7 @@ func TestCookieJar(t *testing.T) {
 	registry := prometheus.NewRegistry()
 	testCTX, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
-	result := ProbeHTTP(testCTX, ts.URL, config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true}}, registry, log.NewNopLogger())
+	result := ProbeHTTP(testCTX, ts.URL, config.Module{Timeout: time.Second, HTTP: config.HTTPProbe{IPProtocolFallback: true, HTTPClientConfig: pconfig.DefaultHTTPClientConfig}}, registry, log.NewNopLogger())
 	body := recorder.Body.String()
 	if !result {
 		t.Fatalf("Redirect test failed unexpectedly, got %s", body)