Add support for HTTP request body as file

Resolves #391

Signed-off-by: Daniel Teunis <daniel@teunis.cc>

CONFIGURATION.md

@@ -129,7 +129,11 @@ The other placeholders are specified separately.
   [ ip_protocol_fallback: <boolean> | default = true ]
 
   # The body of the HTTP request used in probe.
-  body: [ <string> ]
+  [ body: <string> ]
+
+  # Read the HTTP request body from from a file.
+  # It is mutually exclusive with `body`.
+  [ body_file: <filename> ]
 
 ```
 

config/config.go

@@ -218,6 +218,7 @@ type HTTPProbe struct {
 	FailIfHeaderMatchesRegexp    []HeaderMatch           `yaml:"fail_if_header_matches,omitempty"`
 	FailIfHeaderNotMatchesRegexp []HeaderMatch           `yaml:"fail_if_header_not_matches,omitempty"`
 	Body                         string                  `yaml:"body,omitempty"`
+	BodyFile                     string                  `yaml:"body_file,omitempty"`
 	HTTPClientConfig             config.HTTPClientConfig `yaml:"http_client_config,inline"`
 	Compression                  string                  `yaml:"compression,omitempty"`
 	BodySizeLimit                units.Base2Bytes        `yaml:"body_size_limit,omitempty"`
@@ -330,6 +331,10 @@ func (s *HTTPProbe) UnmarshalYAML(unmarshal func(interface{}) error) error {
 		s.HTTPClientConfig.FollowRedirects = !*s.NoFollowRedirects
 	}
 
+	if s.Body != "" && s.BodyFile != "" {
+		return errors.New("setting body and body_file both are not allowed")
+	}
+
 	for key, value := range s.Headers {
 		switch textproto.CanonicalMIMEHeaderKey(key) {
 		case "Accept-Encoding":

config/config_test.go

@@ -99,6 +99,10 @@ func TestLoadBadConfigs(t *testing.T) {
 			input: "testdata/invalid-tcp-query-response-regexp.yml",
 			want:  `error parsing config file: "Could not compile regular expression" regexp=":["`,
 		},
+		{
+			input: "testdata/invalid-http-body-config.yml",
+			want:  `error parsing config file: setting body and body_file both are not allowed`,
+		},
 	}
 	for _, test := range tests {
 		t.Run(test.input, func(t *testing.T) {

config/testdata/invalid-http-body-config.yml

@@ -0,0 +1,7 @@
+modules:
+  http_test:
+    prober: http
+    timeout: 5s
+    http:
+      body: "Test body"
+      body_file: "test_body.txt"

example.yml

@@ -41,6 +41,12 @@ modules:
       headers:
         Content-Type: application/json
       body: '{}'
+  http_post_body_file:
+    prober: http
+    timeout: 5s
+    http:
+      method: POST
+      body_file: "/files/body.txt"
   http_basic_auth_example:
     prober: http
     timeout: 5s

prober/http.go

@@ -27,6 +27,7 @@ import (
 	"net/http/httptrace"
 	"net/textproto"
 	"net/url"
+	"os"
 	"strconv"
 	"strings"
 	"sync"
@@ -408,6 +409,17 @@ func ProbeHTTP(ctx context.Context, target string, module config.Module, registr
 		body = strings.NewReader(httpConfig.Body)
 	}
 
+	// If a body file is configured, add its content to the request.
+	if httpConfig.BodyFile != "" {
+		body_file, err := os.Open(httpConfig.BodyFile)
+		if err != nil {
+			level.Error(logger).Log("msg", "Error creating request", "err", err)
+			return
+		}
+		defer body_file.Close()
+		body = body_file
+	}
+
 	request, err := http.NewRequest(httpConfig.Method, targetURL.String(), body)
 	if err != nil {
 		level.Error(logger).Log("msg", "Error creating request", "err", err)

prober/http_test.go

@@ -1409,25 +1409,48 @@ func TestSkipResolvePhase(t *testing.T) {
 
 func TestBody(t *testing.T) {
 	body := "Test Body"
-	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		b, err := ioutil.ReadAll(r.Body)
-		if err != nil {
-			t.Fatalf("Body test failed unexpectedly.")
-		}
-		if string(b) != body {
-			t.Fatalf("Body test failed unexpectedly.")
-		}
-	}))
-	defer ts.Close()
+	tmpBodyFile, err := os.CreateTemp("", "body.txt")
+	if err != nil {
+		t.Fatalf("Error creating body tempfile: %s", err)
+	}
+	if _, err := tmpBodyFile.Write([]byte(body)); err != nil {
+		t.Fatalf("Error writing body tempfile: %s", err)
+	}
+	if err := tmpBodyFile.Close(); err != nil {
+		t.Fatalf("Error closing body tempfie: %s", err)
+	}
 
-	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,
-		Body:               body,
-	}}, registry, log.NewNopLogger())
-	if !result {
-		t.Fatalf("Body test failed unexpectedly.")
+	tests := []config.HTTPProbe{
+		{IPProtocolFallback: true, Body: body},
+		{IPProtocolFallback: true, BodyFile: tmpBodyFile.Name()},
+	}
+
+	for i, test := range tests {
+		ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			b, err := ioutil.ReadAll(r.Body)
+			if err != nil {
+				t.Fatalf("Body test %d failed unexpectedly.", i)
+			}
+			if string(b) != body {
+				t.Fatalf("Body test %d failed unexpectedly.", i)
+			}
+		}))
+		defer ts.Close()
+
+		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:    test},
+			registry,
+			log.NewNopLogger(),
+		)
+		if !result {
+			t.Fatalf("Body test %d failed unexpectedly.", i)
+		}
 	}
 }