refactor(api): API overhaul (#392)

api/http/handler.go

@@ -0,0 +1,76 @@
+package http
+
+import (
+	"github.com/portainer/portainer"
+
+	"encoding/json"
+	"log"
+	"net/http"
+	"strings"
+)
+
+// Handler is a collection of all the service handlers.
+type Handler struct {
+	AuthHandler      *AuthHandler
+	UserHandler      *UserHandler
+	SettingsHandler  *SettingsHandler
+	TemplatesHandler *TemplatesHandler
+	DockerHandler    *DockerHandler
+	WebSocketHandler *WebSocketHandler
+	FileHandler      http.Handler
+}
+
+const (
+	// ErrInvalidJSON defines an error raised the app is unable to parse request data
+	ErrInvalidJSON = portainer.Error("Invalid JSON")
+	// ErrInvalidRequestFormat defines an error raised when the format of the data sent in a request is not valid
+	ErrInvalidRequestFormat = portainer.Error("Invalid request data format")
+)
+
+// ServeHTTP delegates a request to the appropriate subhandler.
+func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if strings.HasPrefix(r.URL.Path, "/api/auth") {
+		http.StripPrefix("/api", h.AuthHandler).ServeHTTP(w, r)
+	} else if strings.HasPrefix(r.URL.Path, "/api/users") {
+		http.StripPrefix("/api", h.UserHandler).ServeHTTP(w, r)
+	} else if strings.HasPrefix(r.URL.Path, "/api/settings") {
+		http.StripPrefix("/api", h.SettingsHandler).ServeHTTP(w, r)
+	} else if strings.HasPrefix(r.URL.Path, "/api/templates") {
+		http.StripPrefix("/api", h.TemplatesHandler).ServeHTTP(w, r)
+	} else if strings.HasPrefix(r.URL.Path, "/api/websocket") {
+		http.StripPrefix("/api", h.WebSocketHandler).ServeHTTP(w, r)
+	} else if strings.HasPrefix(r.URL.Path, "/api/docker") {
+		http.StripPrefix("/api/docker", h.DockerHandler).ServeHTTP(w, r)
+	} else if strings.HasPrefix(r.URL.Path, "/") {
+		h.FileHandler.ServeHTTP(w, r)
+	}
+}
+
+// Error writes an API error message to the response and logger.
+func Error(w http.ResponseWriter, err error, code int, logger *log.Logger) {
+	// Log error.
+	logger.Printf("http error: %s (code=%d)", err, code)
+
+	// Write generic error response.
+	w.WriteHeader(code)
+	json.NewEncoder(w).Encode(&errorResponse{Err: err.Error()})
+}
+
+// errorResponse is a generic response for sending a error.
+type errorResponse struct {
+	Err string `json:"err,omitempty"`
+}
+
+// handleNotAllowed writes an API error message to the response and sets the Allow header.
+func handleNotAllowed(w http.ResponseWriter, allowedMethods []string) {
+	w.Header().Set("Allow", strings.Join(allowedMethods, ", "))
+	w.WriteHeader(http.StatusMethodNotAllowed)
+	json.NewEncoder(w).Encode(&errorResponse{Err: http.StatusText(http.StatusMethodNotAllowed)})
+}
+
+// encodeJSON encodes v to w in JSON format. Error() is called if encoding fails.
+func encodeJSON(w http.ResponseWriter, v interface{}, logger *log.Logger) {
+	if err := json.NewEncoder(w).Encode(v); err != nil {
+		Error(w, err, http.StatusInternalServerError, logger)
+	}
+}