Update file backend to allow optional http headers

docs/content/config/configuration-options.md

@@ -125,6 +125,8 @@ See the example configuration to see how global default values can be set for in
 
  - **filepath(string):**
    - The filepath to a yaml or json file containing the key-value pairs. This can be a local file or a remote http/https location.
+ - **httpheader(map[string]string):**
+   - Optional HTTP-headers to append to the request if the file path is a remote http/https location. 
 </details>
 
 <details>

docs/content/config/sample-config.md

@@ -67,6 +67,7 @@ log_file    = "/var/log/remco.log"
       keys     = ["/"]
 
     [resource.backend.file]
+      httpheader = { X-Test-Token = "XXX", X-Test-Token2 = "YYY" } 
       filepath = "/etc/remco/test.yml"
 	    watch    = true
 	    keys     = ["/prefix"]

integration/file/file.toml

@@ -18,4 +18,5 @@ log_format = "text"
     [resource.backend.file]
       onetime = true
       filepath = "./integration/file/config.yml"
+      httpheader = { X-Test-Token = "XXX", X-Test-Token2 = "YYY" }
       keys = ["/"]

pkg/backends/file.go

@@ -21,6 +21,9 @@ type FileConfig struct {
 	// The filepath to a yaml or json file containing the key-value pairs.
 	// This can be a local file or a remote http/https location.
 	Filepath string
+
+	// Optional HTTP headers to append to the request if the file path is a remote http/https location.
+	HTTPHeader map[string]string
 	template.Backend
 }
 
@@ -36,7 +39,7 @@ func (c *FileConfig) Connect() (template.Backend, error) {
 		"filepath": c.Filepath,
 	}).Info("set file path")
 
-	client, err := file.New(c.Filepath)
+	client, err := file.New(c.Filepath, file.WithHeaders(c.HTTPHeader))
 	if err != nil {
 		return c.Backend, err
 	}