frontend: add API

frontend/api.go

@@ -0,0 +1,116 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+)
+
+type apiRequest struct {
+	Servers []string `json:"servers"`
+	Type    string   `json:"type"`
+	Args    string   `json:"args"`
+}
+
+type apiGenericResultPair struct {
+	Server string `json:"server"`
+	Data   string `json:"data"`
+}
+
+type apiSummaryResultPair struct {
+	Server string           `json:"server"`
+	Data   []SummaryRowData `json:"data"`
+}
+
+type apiResponse struct {
+	Error  string        `json:"error"`
+	Result []interface{} `json:"result"`
+}
+
+var apiHandlerMap = map[string](func(request apiRequest) apiResponse){
+	"summary":    apiSummaryHandler,
+	"bird":       apiGenericHandlerFactory("bird"),
+	"traceroute": apiGenericHandlerFactory("traceroute"),
+	"whois":      apiWhoisHandler,
+}
+
+func apiGenericHandlerFactory(endpoint string) func(request apiRequest) apiResponse {
+	return func(request apiRequest) apiResponse {
+		results := batchRequest(request.Servers, endpoint, request.Args)
+		var response apiResponse
+
+		for i, result := range results {
+			response.Result = append(response.Result, &apiGenericResultPair{
+				Server: request.Servers[i],
+				Data:   result,
+			})
+		}
+
+		return response
+	}
+}
+
+func apiSummaryHandler(request apiRequest) apiResponse {
+	results := batchRequest(request.Servers, "bird", "show protocols")
+	var response apiResponse
+
+	for i, result := range results {
+		parsedSummary, err := summaryParse(result, request.Servers[i])
+		if err != nil {
+			return apiResponse{
+				Error: err.Error(),
+			}
+		}
+
+		response.Result = append(response.Result, &apiSummaryResultPair{
+			Server: request.Servers[i],
+			Data:   parsedSummary.Rows,
+		})
+	}
+
+	return response
+}
+
+func apiWhoisHandler(request apiRequest) apiResponse {
+	return apiResponse{
+		Error: "",
+		Result: []interface{}{
+			apiGenericResultPair{
+				Server: "",
+				Data:   whois(request.Args),
+			},
+		},
+	}
+}
+
+func apiErrorHandler(err error) apiResponse {
+	return apiResponse{
+		Error: err.Error(),
+	}
+}
+
+func apiHandler(w http.ResponseWriter, r *http.Request) {
+	var request apiRequest
+	var response apiResponse
+	err := json.NewDecoder(r.Body).Decode(&request)
+	if err != nil {
+		response = apiResponse{
+			Error: err.Error(),
+		}
+	} else {
+		handler := apiHandlerMap[request.Type]
+		if handler == nil {
+			response = apiErrorHandler(errors.New("Invalid request type"))
+		} else {
+			response = handler(request)
+		}
+	}
+
+	w.Header().Add("Content-Type", "application/json")
+	bytes, err := json.Marshal(response)
+	if err != nil {
+		println(err.Error())
+		return
+	}
+	w.Write(bytes)
+}