Support multipart/form-data

CONFIGURATION.md

@@ -25,8 +25,8 @@ modules:
 
 ```
 
-
 ### `<module>`
+
 ```yml
 
   # The protocol over which the probe will take place (http, tcp, dns, icmp, grpc).
@@ -45,6 +45,7 @@ modules:
 ```
 
 ### `<http_probe>`
+
 ```yml
 
   # Accepted status codes for this probe. Defaults to 2xx.
@@ -157,9 +158,13 @@ modules:
   [ body: <string> ]
 
   # Read the HTTP request body from from a file.
-  # It is mutually exclusive with `body`.
+  # It is mutually exclusive with `body` and `body_multipart`.
   [ body_file: <filename> ]
 
+  # Read the HTTP request body from from a file.
+  # It is mutually exclusive with `body` and `body_file`.
+  [ body_multipart: <filename> ]
+    [ - <body_multipart_spec>, ... ]
 ```
 
 #### `<http_header_match_spec>`
@@ -170,6 +175,17 @@ regexp: <regex>,
 [ allow_missing: <boolean> | default = false ]
 ```
 
+#### `<body_multipart_spec>`
+
+```yml
+# The type of the multipart body part. Valid values are "file" and "text".
+type: <string>
+# The name of the multipart body part.
+key: <string>
+# The value of the multipart body part. It can be a file path or a string.
+value: <string>
+```
+
 ### `<tcp_probe>`
 
 ```yml

config/config.go

@@ -220,11 +220,18 @@ type HTTPProbe struct {
 	FailIfHeaderNotMatchesRegexp []HeaderMatch           `yaml:"fail_if_header_not_matches,omitempty"`
 	Body                         string                  `yaml:"body,omitempty"`
 	BodyFile                     string                  `yaml:"body_file,omitempty"`
+	BodyMultipart                []Multipart             `yaml:"body_multipart,omitempty"`
 	HTTPClientConfig             config.HTTPClientConfig `yaml:"http_client_config,inline"`
 	Compression                  string                  `yaml:"compression,omitempty"`
 	BodySizeLimit                units.Base2Bytes        `yaml:"body_size_limit,omitempty"`
 }
 
+type Multipart struct {
+	Type  string `yaml:"type,omitempty"`
+	Key   string `yaml:"key,omitempty"`
+	Value string `yaml:"value,omitempty"`
+}
+
 type GRPCProbe struct {
 	Service             string           `yaml:"service,omitempty"`
 	TLS                 bool             `yaml:"tls,omitempty"`

example.yml

@@ -54,6 +54,18 @@ modules:
     http:
       method: POST
       body_file: "/files/body.txt"
+  http_post_body_multipart:
+    prober: http
+    timeout: 5s
+    http:
+      method: POST
+      body_multipart:
+        - type: "file"
+          key: "file"
+          value: "/files/body.txt"
+        - type: "text"
+          key: "name"
+          value: "arash"
   http_basic_auth_example:
     prober: http
     timeout: 5s

prober/http.go

@@ -14,13 +14,15 @@
 package prober
 
 import (
+	"bytes"
 	"compress/flate"
 	"compress/gzip"
 	"context"
 	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
+	"mime/multipart"
 	"net"
 	"net/http"
 	"net/http/cookiejar"
@@ -420,6 +422,56 @@ func ProbeHTTP(ctx context.Context, target string, module config.Module, registr
 		body = body_file
 	}
 
+	// If a multipart form is configured, add it to the request.
+	if httpConfig.BodyMultipart != nil {
+		var (
+			b bytes.Buffer
+			r io.Reader
+		)
+		w := multipart.NewWriter(&b)
+		for _, part := range httpConfig.BodyMultipart {
+			if part.Type == "file" {
+				r, err = os.Open(part.Value)
+				if err != nil {
+					level.Error(logger).Log("msg", "Error reading body file", "err", err)
+					return
+				}
+			} else {
+				r = strings.NewReader(part.Value)
+			}
+
+			var fw io.Writer
+			if x, ok := r.(io.Closer); ok {
+				defer x.Close()
+			}
+			// Add a file field
+			if x, ok := r.(*os.File); ok {
+				if fw, err = w.CreateFormFile(part.Key, x.Name()); err != nil {
+					level.Error(logger).Log("msg", "Error creating request", "err", err)
+					return
+				}
+			} else {
+				// Add a text fields
+				if fw, err = w.CreateFormField(part.Key); err != nil {
+					level.Error(logger).Log("msg", "Error creating request", "err", err)
+					return
+				}
+			}
+			if _, err = io.Copy(fw, r); err != nil {
+				level.Error(logger).Log("msg", "Error creating request", "err", err)
+				return
+			}
+		}
+		// We should close the multipart writer.
+		// If we don't close it, your request will be missing the terminating boundary.
+		w.Close()
+
+		body = &b
+
+		// Set the proper content-type header containing the boundary.
+		httpConfig.Headers["Content-Type"] = w.FormDataContentType()
+	}
+
 	request, err := http.NewRequest(httpConfig.Method, targetURL.String(), body)
 	if err != nil {
 		level.Error(logger).Log("msg", "Error creating request", "err", err)