Update to 6.0.9: Add PostInterrupt plugin. Read HISTORY.md

- Add `PostInterrupt` plugin, useful for customization of the
**os.Interrupt** singal, before that Iris closed the server
automatically.

```go
iris.Plugins.PostInterrupt(func(s *Framework){
// when os.Interrupt signal is fired the body of this function will be
fired,
// you're responsible for closing the server with s.Close()

// if that event is not registered then the framework
// will close the server for you.

/* Do  any custom cleanup and finally call the s.Close()
remember you have the iris.Plugins.PreClose(func(s *Framework)) event
too
so you can split your logic in two logically places.
*/

})

```

.github/ISSUE_TEMPLATE.md

@@ -1,4 +1,4 @@
-- Version : **6.0.8**
+- Version : **6.0.9**
 
 - Operating System:
 

HISTORY.md

@@ -2,6 +2,29 @@
 
 **How to upgrade**: remove your `$GOPATH/src/github.com/kataras` folder, open your command-line and execute this command: `go get -u github.com/kataras/iris/iris`.
 
+## 6.0.8 -> 6.0.9
+
+- Add `PostInterrupt` plugin, useful for customization of the **os.Interrupt** singal, before that Iris closed the server automatically.
+
+```go
+iris.Plugins.PostInterrupt(func(s *Framework){
+  // when os.Interrupt signal is fired the body of this function will be fired,
+  // you're responsible for closing the server with s.Close()
+
+  // if that event is not registered then the framework
+  // will close the server for you.
+
+
+
+  /* Do  any custom cleanup and finally call the s.Close()
+     remember you have the iris.Plugins.PreClose(func(s *Framework)) event too
+     so you can split your logic in two logically places.
+  */   
+
+})
+
+```
+
 ## 6.0.7 -> 6.0.8
 
 - Add `iris.UseTemplateFunc(functionName string, function interface{})`. You could always set custom template funcs by using each of [template engine's](https://github.com/kataras/go-template) configuration but this function will help newcomers to start creating their custom template funcs.

README.md

@@ -18,7 +18,7 @@
 <br/>
 
 
-<a href="https://github.com/kataras/iris/blob/master/HISTORY.md"><img src="https://img.shields.io/badge/%20version%20-%206.0.8%20-blue.svg?style=flat-square" alt="CHANGELOG/HISTORY"></a>
+<a href="https://github.com/kataras/iris/blob/master/HISTORY.md"><img src="https://img.shields.io/badge/%20version%20-%206.0.9%20-blue.svg?style=flat-square" alt="CHANGELOG/HISTORY"></a>
 
 <a href="https://github.com/iris-contrib/examples"><img src="https://img.shields.io/badge/%20examples-repository-3362c2.svg?style=flat-square" alt="Examples"></a>
 
@@ -129,7 +129,7 @@ $ go run hellojson.go
 ```
 > TIP #1> $ iris run main.go to enable hot-reload on .go source code changes.
 
-> TIP #2> iris.Config.IsDevelopment = true to monitor the changes you make in the templates. 
+> TIP #2> iris.Config.IsDevelopment = true to monitor the changes you make in the templates.
 
 
 Open your browser or any other http client at http://localhost:6000/api/user/42.
@@ -947,7 +947,7 @@ I recommend testing your API using this new library, [httpexpect](https://github
 Versioning
 ------------
 
-Current: **v6.0.8**
+Current: **v6.0.9**
 
 Older: **[v5/fasthttp](https://github.com/kataras/iris/tree/5.0.0)**
 

iris.go

@@ -66,6 +66,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/kataras/go-errors"
@@ -80,7 +81,7 @@ const (
 	// IsLongTermSupport flag is true when the below version number is a long-term-support version
 	IsLongTermSupport = false
 	// Version is the current version number of the Iris web framework
-	Version = "6.0.8"
+	Version = "6.0.9"
 
 	banner = `         _____      _
         |_   _|    (_)
@@ -478,21 +479,51 @@ func (s *Framework) Serve(ln net.Listener) error {
 	}
 	// maybe a 'race' here but user should not call .Serve more than one time especially in more than one go routines...
 	s.ln = ln
-
+	// build the handler and all other components
 	s.Build()
+	// fire all PreListen plugins
 	s.Plugins.DoPreListen(s)
 
-	// This didn't helped me ,here, but maybe can help you:
-	// https://www.oreilly.com/learning/run-strikingly-fast-parallel-file-searches-in-go-with-sync-errgroup?utm_source=golangweekly&utm_medium=email
-	// new experimental package: errgroup
-
+	// catch any panics to the user defined logger.
 	defer func() {
 		if err := recover(); err != nil {
 			s.Logger.Panic(err)
 		}
 	}()
-	// start the server in goroutine, .Available will block instead
-	go func() { s.Must(s.srv.Serve(ln)) }()
+
+	// prepare for 'after serve' actions
+	var stop uint32
+	go func() {
+		// wait for the server's Serve func (309 mill is a lot or not, I found that this number is the perfect for most of the environments.)
+		time.Sleep(309 * time.Millisecond)
+		if atomic.LoadUint32(&stop) > 0 {
+			return
+		}
+		// print the banner
+		// fire the PostListen plugins
+		// wait for system channel interrupt
+		// fire the PostInterrupt plugins or close and exit.
+		s.postServe()
+	}()
+
+	serverStartUpErr := s.srv.Serve(ln)
+	if serverStartUpErr != nil {
+		// if an error then it would be nice to stop the banner and all next plugin events.
+		atomic.AddUint32(&stop, 1)
+	}
+	// finally return the error or block here, remember,
+	// you can always use the iris.Available to 'see' if and when the server is up (virtually),
+	// until go1.8 these are our best options.
+	return serverStartUpErr
+}
+
+// runs only when server starts without errors
+// what it does?
+// 0. print the banner
+// 1. fire the PostListen plugins
+// 2. wait for system channel interrupt
+// 3. fire the PostInterrupt plugins or close and exit.
+func (s *Framework) postServe() {
 
 	if !s.Config.DisableBanner {
 		bannerMessage := fmt.Sprintf("%s: Running at %s", time.Now().Format(s.Config.TimeFormat), s.Config.VHost)
@@ -506,17 +537,22 @@ func (s *Framework) Serve(ln net.Listener) error {
 	s.Plugins.DoPostListen(s)
 
 	go func() { s.Available <- true }()
+
 	ch := make(chan os.Signal, 1)
 	signal.Notify(ch, os.Interrupt)
 	<-ch
-	if err := s.Close(); err != nil {
-		if s.Config.IsDevelopment {
-			s.Logger.Printf("Error while closing the server: %s\n", err)
+	// catch custom plugin event for interrupt
+	s.Plugins.DoPostInterrupt(s)
+	if !s.Plugins.PostInterruptFired() {
+		// if no PostInterrupt events fired, then I assume that the user doesn't cares
+		// so close the server automatically.
+		if err := s.Close(); err != nil {
+			if s.Config.IsDevelopment {
+				s.Logger.Printf("Error while closing the server: %s\n", err)
+			}
 		}
-		return err
+		os.Exit(1)
 	}
-	os.Exit(1)
-	return nil
 }
 
 // Listen starts the standalone http server

plugin.go

@@ -89,6 +89,20 @@ type (
 	}
 	// PostListenFunc implements the simple function listener for the PostListen(*Framework)
 	PostListenFunc func(*Framework)
+
+	// pluginPostInterrupt implements the PostInterrupt(*Framework) method
+	pluginPostInterrupt interface {
+		// PostInterrupt it's being called only one time, when os.Interrupt system event catched
+		// graceful shutdown can be done here
+		//
+		// Read more here: https://github.com/kataras/iris/blob/master/HISTORY.md#608---609
+		PostInterrupt(*Framework)
+	}
+	// PostInterruptFunc implements the simple function listener for the PostInterrupt(*Framework)
+	//
+	// Read more here: https://github.com/kataras/iris/blob/master/HISTORY.md#608---609
+	PostInterruptFunc func(*Framework)
+
 	// pluginPreClose implements the PreClose(*Framework) method
 	pluginPreClose interface {
 		// PreClose it's being called only one time, BEFORE the Iris .Close method
@@ -139,6 +153,9 @@ type (
 		PostListen(PostListenFunc)
 		DoPostListen(*Framework)
 		PostListenFired() bool
+		PostInterrupt(PostInterruptFunc)
+		DoPostInterrupt(*Framework)
+		PostInterruptFired() bool
 		PreClose(PreCloseFunc)
 		DoPreClose(*Framework)
 		PreCloseFired() bool
@@ -520,6 +537,29 @@ func (p *pluginContainer) PostListenFired() bool {
 	return p.Fired("postlisten") > 0
 }
 
+// PostInterrupt adds a PostInterrupt plugin-function to the plugin flow container
+//
+// Read more here: https://github.com/kataras/iris/blob/master/HISTORY.md#608---609
+func (p *pluginContainer) PostInterrupt(fn PostInterruptFunc) {
+	p.Add(fn)
+}
+
+// DoPostInterrupt raise all plugins which has the PostInterrupt method
+func (p *pluginContainer) DoPostInterrupt(station *Framework) {
+	for i := range p.activatedPlugins {
+		// check if this method exists on our plugin obj, these are optionaly and call it
+		if pluginObj, ok := p.activatedPlugins[i].(pluginPostInterrupt); ok {
+			pluginObj.PostInterrupt(station)
+			p.fire("postinterrupt")
+		}
+	}
+}
+
+// PostInterruptFired returns true if PostInterrupt event/ plugin type is fired at least one time
+func (p *pluginContainer) PostInterruptFired() bool {
+	return p.Fired("postinterrupt") > 0
+}
+
 // PreClose adds a PreClose plugin-function to the plugin flow container
 func (p *pluginContainer) PreClose(fn PreCloseFunc) {
 	p.Add(fn)