feat: propagate signals to launched subprocesses so that they can pro…

…perly clean up resources

command/cleanup.go

@@ -7,8 +7,10 @@ import (
 	"log"
 	"os"
 	"os/exec"
+	"os/signal"
 	"strconv"
 	"strings"
+	"syscall"
 
 	"github.com/google/go-github/github"
 	cli "gopkg.in/urfave/cli.v1"
@@ -71,7 +73,12 @@ func CmdCleanup(c *cli.Context) (err error) {
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
 
+		signalChannel := make(chan os.Signal, 1)
+		signal.Notify(signalChannel, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
+		go propagateSignalsTo(cmd, signalChannel)
+
 		err = cmd.Run()
+		signal.Stop(signalChannel)
 		if err != nil {
 			log.Println("undeploy error: ", err)
 
@@ -108,7 +115,13 @@ func listDeployedPullRequests(listScript string) ([]string, error) {
 	cmd := exec.Command(listScript)
 	cmd.Stdout = &stdout
 
-	if err := cmd.Run(); err != nil {
+	signalChannel := make(chan os.Signal, 1)
+	signal.Notify(signalChannel, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
+	go propagateSignalsTo(cmd, signalChannel)
+
+	err := cmd.Run()
+	signal.Stop(signalChannel)
+	if err != nil {
 		return nil, err
 	}
 

command/please.go

@@ -9,8 +9,10 @@ import (
 	"log"
 	"os"
 	"os/exec"
+	"os/signal"
 	"strconv"
 	"strings"
+	"syscall"
 
 	"github.com/google/go-github/github"
 	cli "gopkg.in/urfave/cli.v1"
@@ -151,6 +153,10 @@ func CmdPlease(c *cli.Context) (err error) {
 	}
 
 	// Start deploy script
+	signalChannel := make(chan os.Signal, 1)
+	signal.Notify(signalChannel, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
+	go propagateSignalsTo(cmd, signalChannel)
+
 	err = cmd.Start()
 	if err != nil {
 		err2 := updateStatus(StateError, "")
@@ -169,6 +175,8 @@ func CmdPlease(c *cli.Context) (err error) {
 
 	// Wait on the deploy to finish
 	err = cmd.Wait()
+	signal.Stop(signalChannel)
+
 	if err != nil {
 		err2 := updateStatus(StateFailure, "")
 		if err2 != nil {

command/utils.go

@@ -3,6 +3,8 @@ package command
 import (
 	"context"
 	"log"
+	"os"
+	"os/exec"
 	"regexp"
 
 	"github.com/google/go-github/github"
@@ -61,3 +63,17 @@ func refString(str string) *string {
 func refStringList(l []string) *[]string {
 	return &l
 }
+
+func propagateSignalsTo(cmd *exec.Cmd, signalChannel chan os.Signal) {
+	for sig := range signalChannel {
+		if cmd.Process != nil {
+			err := cmd.Process.Signal(sig)
+			if err != nil {
+				log.Printf("error sending signal to child process (%d): %s\n", cmd.Process.Pid, err)
+			}
+		} else {
+			// TODO: is this always the right thing to do if we're not running a subprocess?
+			os.Exit(1)
+		}
+	}
+}