use go 1.12

Signed-off-by: hongming <talonwan@yunify.com>

vendor/github.com/mholt/caddy/caddyhttp/expvar/setup.go

@@ -0,0 +1,83 @@
+// Copyright 2015 Light Code Labs, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expvar
+
+import (
+	"expvar"
+	"runtime"
+	"sync"
+
+	"github.com/mholt/caddy"
+	"github.com/mholt/caddy/caddyhttp/httpserver"
+)
+
+func init() {
+	caddy.RegisterPlugin("expvar", caddy.Plugin{
+		ServerType: "http",
+		Action:     setup,
+	})
+}
+
+// setup configures a new ExpVar middleware instance.
+func setup(c *caddy.Controller) error {
+	resource, err := expVarParse(c)
+	if err != nil {
+		return err
+	}
+
+	// publish any extra information/metrics we may want to capture
+	publishExtraVars()
+
+	ev := ExpVar{Resource: resource}
+
+	httpserver.GetConfig(c).AddMiddleware(func(next httpserver.Handler) httpserver.Handler {
+		ev.Next = next
+		return ev
+	})
+
+	return nil
+}
+
+func expVarParse(c *caddy.Controller) (Resource, error) {
+	var resource Resource
+	var err error
+
+	for c.Next() {
+		args := c.RemainingArgs()
+		switch len(args) {
+		case 0:
+			resource = Resource(defaultExpvarPath)
+		case 1:
+			resource = Resource(args[0])
+		default:
+			return resource, c.ArgErr()
+		}
+	}
+
+	return resource, err
+}
+
+func publishExtraVars() {
+	// By using sync.Once instead of an init() function, we don't clutter
+	// the app's expvar export unnecessarily, or risk colliding with it.
+	publishOnce.Do(func() {
+		expvar.Publish("Goroutines", expvar.Func(func() interface{} {
+			return runtime.NumGoroutine()
+		}))
+	})
+}
+
+var publishOnce sync.Once // publishing variables should only be done once
+var defaultExpvarPath = "/debug/vars"