add custom headers in writer (#144) (#165)

* add nginx plugin

* update nginx.toml for nginx plugin

* Update nginx.go

* add custom headers in writer

* Update writer.go

Co-authored-by: ulricqin <ulricqin@qq.com>

conf/config.toml

@@ -38,6 +38,9 @@ basic_auth_user = ""
 # Basic auth password
 basic_auth_pass = ""
 
+## Optional headers
+# headers = ["X-From", "categraf", "X-Xyz", "abc"]
+
 # timeout settings, unit: ms
 timeout = 5000
 dial_timeout = 2500

config/config.go

@@ -35,9 +35,10 @@ type WriterOpt struct {
 }
 
 type WriterOption struct {
-	Url           string `toml:"url"`
-	BasicAuthUser string `toml:"basic_auth_user"`
-	BasicAuthPass string `toml:"basic_auth_pass"`
+	Url           string   `toml:"url"`
+	BasicAuthUser string   `toml:"basic_auth_user"`
+	BasicAuthPass string   `toml:"basic_auth_pass"`
+	Headers       []string `toml:"headers"`
 
 	Timeout             int64 `toml:"timeout"`
 	DialTimeout         int64 `toml:"dial_timeout"`

writer/writer.go

@@ -52,6 +52,13 @@ func (w WriterType) Post(req []byte) error {
 	httpReq.Header.Set("User-Agent", "categraf")
 	httpReq.Header.Set("X-Prometheus-Remote-Write-Version", "0.1.0")
 
+	for i := 0; i < len(w.Opts.Headers); i += 2 {
+		httpReq.Header.Add(w.Opts.Headers[i], w.Opts.Headers[i+1])
+		if w.Opts.Headers[i] == "Host" {
+			httpReq.Host = w.Opts.Headers[i+1]
+		}
+	}
+
 	if w.Opts.BasicAuthUser != "" {
 		httpReq.SetBasicAuth(w.Opts.BasicAuthUser, w.Opts.BasicAuthPass)
 	}