Move API handlers to separate package

This makes the package split a little cleaner and easier to import the
HTTP handlers for other consumers.

vkubelet/api/helpers.go

@@ -0,0 +1,31 @@
+package api
+
+import (
+	"io"
+	"net/http"
+
+	"github.com/cpuguy83/strongerrors/status"
+	"github.com/virtual-kubelet/virtual-kubelet/log"
+)
+
+type handlerFunc func(http.ResponseWriter, *http.Request) error
+
+func handleError(f handlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		err := f(w, req)
+		if err == nil {
+			return
+		}
+
+		code, _ := status.HTTPCode(err)
+		w.WriteHeader(code)
+		io.WriteString(w, err.Error())
+		logger := log.G(req.Context()).WithError(err).WithField("httpStatusCode", code)
+
+		if code >= 500 {
+			logger.Error("Internal server error on request")
+		} else {
+			log.Trace(logger, "Error on request")
+		}
+	}
+}