Merge pull request #122 from hasLeland/shutdown-hook

Add hook for controlling shutdown in truss

gengokit/generator/gen.go

@@ -70,6 +70,11 @@ func generateResponseFile(templFP string, data *gengokit.Data, prevFile io.Reade
 		if genCode, err = h.Render(templFP, data); err != nil {
 			return nil, errors.Wrapf(err, "cannot render template: %s", templFP)
 		}
+	case handler.HookPath:
+		hook := handler.NewHook(prevFile)
+		if genCode, err = hook.Render(templFP, data); err != nil {
+			return nil, errors.Wrapf(err, "cannot render template: %s", templFP)
+		}
 	case middlewares.EndpointsPath:
 		m := middlewares.New()
 		m.LoadEndpoints(prevFile)

gengokit/handler/hooks.go

@@ -0,0 +1,31 @@
+package handler
+
+import (
+	"io"
+	"strings"
+
+	"github.com/TuneLab/go-truss/gengokit"
+)
+
+const HookPath = "NAME-service/handlers/server/hooks.gotemplate"
+
+// NewHook returns a new HookRender
+func NewHook(prev io.Reader) gengokit.Renderable {
+	return &HookRender{
+		prev: prev,
+	}
+}
+
+type HookRender struct {
+	prev io.Reader
+}
+
+// Render will return the existing file if it exists, otherwise it will return
+// a brand new copy from the template.
+func (h *HookRender) Render(_ string, _ *gengokit.Data) (io.Reader, error) {
+	if h.prev == nil {
+		return strings.NewReader(hookTempl), nil
+	} else {
+		return h.prev, nil
+	}
+}

gengokit/handler/templates.go

@@ -48,3 +48,23 @@ type {{.PackageName}}Service struct{}
 	{{end}}
 {{- end}}
 `
+const hookTempl = `
+package handler
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func InterruptHandler(errc chan<- error) {
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
+	terminateError := fmt.Errorf("%s", <-c)
+
+	// Place whatever shutdown handling you want here
+
+	errc <- terminateError
+}
+`

gengokit/template/NAME-service/NAME-server/server_main.gotemplate

@@ -7,8 +7,6 @@ import (
 	"net/http"
 	"net/http/pprof"
 	"os"
-	"os/signal"
-	"syscall"
 
 	// 3d Party
 	"golang.org/x/net/context"
@@ -83,11 +81,7 @@ func main() {
 	ctx := context.Background()
 
 	// Interrupt handler.
-	go func() {
-		c := make(chan os.Signal, 1)
-		signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
-		errc <- fmt.Errorf("%s", <-c)
-	}()
+	go handler.InterruptHandler(errc)
 
 	// Debug listener.
 	go func() {

gengokit/template/NAME-service/handlers/server/hooks.gotemplate

@@ -0,0 +1 @@
+{{/* See go-truss/gengokit/handler/templates.go for code */}}