feat(api): implement new api handler

pkg/api/prelude/handler_func.go

@@ -0,0 +1,39 @@
+package prelude
+
+import (
+	log "github.com/sirupsen/logrus"
+	"net/http"
+)
+
+type HandlerFunc func(c *Context) Response
+
+func (hf HandlerFunc) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+
+	w.Header().Set("Content-Type", DefaultContentType)
+	context := newContext(w, req)
+
+	reqLog := context.Log.WithFields(log.Fields{
+		"query": req.URL.RawQuery,
+	})
+	reqLog.Trace("Received API Request")
+
+	res := hf(context)
+
+	status := res.Status
+
+	bytes, err := res.Bytes()
+	if err != nil {
+		context.Log.WithError(err).Errorf("Failed to create JSON payload for response")
+		bytes = []byte(internalErrorPayload)
+		status = http.StatusInternalServerError
+		// Reset the content-type in case the handler changed it
+		w.Header().Set("Content-Type", DefaultContentType)
+	}
+
+	reqLog.WithField("status", status).Trace("Handled API Request")
+
+	w.WriteHeader(status)
+	if _, err = w.Write(bytes); err != nil {
+		localLog.Errorf("Failed to write HTTP response: %v", err)
+	}
+}