Beginnings of administrative API.

The "stats.json" file is moved under "galene-api", where the rest
of the API will live.

webserver/api.go

@@ -0,0 +1,57 @@
+package webserver
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"strings"
+
+	"github.com/jech/galene/stats"
+)
+
+func apiHandler(w http.ResponseWriter, r *http.Request) {
+	username, password, ok := r.BasicAuth()
+	if !ok {
+		failAuthentication(w, "galene-api")
+		return
+	}
+
+	if ok, err := adminMatch(username, password); !ok {
+		if err != nil {
+			log.Printf("Administrator password: %v", err)
+		}
+		failAuthentication(w, "galene-api")
+		return
+	}
+
+	if !strings.HasPrefix(r.URL.Path, "/galene-api/") {
+		http.NotFound(w, r)
+		return
+	}
+
+	first, kind, rest := splitPath(r.URL.Path[len("/galene/api"):])
+	if first != "" {
+		http.NotFound(w, r)
+		return
+	}
+
+	if kind == ".stats" && rest == "" {
+		if r.Method != "HEAD" && r.Method != "GET" {
+			http.Error(w, "method not allowed",
+				http.StatusMethodNotAllowed)
+		}
+		w.Header().Set("content-type", "application/json")
+		w.Header().Set("cache-control", "no-cache")
+		if r.Method == "HEAD" {
+			return
+		}
+
+		ss := stats.GetGroups()
+		e := json.NewEncoder(w)
+		e.Encode(ss)
+		return
+	}
+
+	http.NotFound(w, r)
+	return
+}