Some fixes suggested by golangci-lint

internal/server/model/handler.go

@@ -5,10 +5,25 @@ import (
 	"sync"
 )
 
+// Handler represents an open HTTP connection in the User Server.
+//
+// This struct contains the connection Writer and Request to be managed
+// by endpoints of the Data Server.
 type Handler struct {
-	Id      string
-	Route   *Route
+	// ID is unique identifier of the request.
+	ID string
+
+	// Route is a reference to the original route that matched this
+	// request.
+	Route *Route
+
+	// Writing is a mutex that prevents two goroutines from writing at
+	// the same time in the response.
 	Writing sync.Mutex
-	Writer  http.ResponseWriter
+
+	// Request is a pointer to the in-progress request.
 	Request *http.Request
+
+	// Writer is the original http.ResponseWriter of the request.
+	Writer http.ResponseWriter
 }

internal/server/model/route.go

@@ -1,9 +1,25 @@
 package model
 
+// Route contains the data needed to represent a Kapow! user route.
 type Route struct {
-	Id         string `json:"id"`
-	Method     string `json:"method"`
-	Pattern    string `json:"url_pattern"`
+	// ID is the unique identifier of the Route.
+	ID string `json:"id"`
+
+	// Method is the HTTP method that will match this Route.
+	Method string `json:"method"`
+
+	// Pattern is the gorilla/mux path pattern that will match this
+	// Route.
+	Pattern string `json:"url_pattern"`
+
+	// Entrypoint is the string that will be executed when the Route
+	// match.
+	//
+	// This string will be split according to the shell parsing rules to
+	// be passed as a list to exec.Command.
 	Entrypoint string `json:"entrypoint"`
-	Command    string `json:"command"`
+
+	// Command is the last argument to be passed to exec.Command when
+	// executing the Entrypoint
+	Command string `json:"command"`
 }