Merge pull request #6 from kuno1/issue/5

Add maximum lifetime feature
Close #5.

README.md

@@ -1 +1,6 @@
 # Immortalize
+## Usage
+
+```
+immortalize -min-lifetime 30 -max-lifetime 60 -command test-bin/command
+```

immortalize.go

@@ -13,7 +13,7 @@ import (
 
 var log = logrus.New()
 
-func run(minLifetime int, command string) {
+func run(minLifetime uint, maxLifetime uint, command string) {
 	cmd := exec.Command(command)
 	cmd.Stderr = os.Stderr
 	cmd.Stdout = os.Stdout
@@ -29,6 +29,15 @@ func run(minLifetime int, command string) {
 
 	lifetimeChan := make(chan bool)
 
+	if 0 < maxLifetime {
+		go func() {
+			time.Sleep(time.Duration(maxLifetime) * time.Second)
+			log.Info("Maximum lifetime has passed.")
+			cmd.Process.Signal(syscall.SIGTERM)
+			log.Info("Signal 'terminated' has been sent to the process.")
+		}()
+	}
+
 	go func() {
 		time.Sleep(time.Duration(minLifetime) * time.Second)
 		log.Info("Minimum lifetime has passed.")
@@ -40,11 +49,11 @@ func run(minLifetime int, command string) {
 	go func() {
 		for s := range signalChan {
 			if s == syscall.SIGTERM {
-				log.Info("SIGTERM has been received.")
+				log.Infof("Signal '%v' has been received.", s)
 				<-lifetimeChan
 			}
-			log.Infof("Signal '%v' has been forwarded to the process.", s)
 			cmd.Process.Signal(s)
+			log.Infof("Signal '%v' has been forwarded to the process.", s)
 		}
 	}()
 
@@ -71,8 +80,10 @@ func configLog(level string) error {
 }
 
 func main() {
-	minLifetimePtr := flag.Int("min-lifetime", 0,
+	minLifetimePtr := flag.Uint("min-lifetime", 0,
 		"Time duration for minimum process lifetime in seconds")
+	maxLifetimePtr := flag.Uint("max-lifetime", 0,
+		"Time duration for maximum process lifetime in seconds")
 	commandPtr := flag.String("command", "command", "command to immortalize")
 	levelPtr := flag.String(
 		"log-level", "info", "Log level: 'info', 'debug', or 'trace'")
@@ -82,5 +93,9 @@ func main() {
 
 	log.Debugf("PID: %v", os.Getpid())
 
-	run(*minLifetimePtr, *commandPtr)
+	if 0 < *maxLifetimePtr && *maxLifetimePtr < *minLifetimePtr {
+		log.Fatal("min-lifetime cannot be higher than max-lifetime.")
+	}
+
+	run(*minLifetimePtr, *maxLifetimePtr, *commandPtr)
 }

test/test.bats

@@ -23,7 +23,7 @@ measure () {
   # Measure immortalize and redirect stdout/stderr to file descriptor 3.
   # Details:
   # https://github.com/bats-core/bats-core#file-descriptor-3-read-this-if-bats-hangs
-  "$time_cmd" -f '%e' -o work/time ./work/immortalize "$@" >&3 2>&1 &
+  "$time_cmd" --quiet -f '%e' -o work/time ./work/immortalize "$@" >&3 2>&1 &
   # Store time's PID
   echo "$!" > work/pid
 }
@@ -33,21 +33,47 @@ sigterm () {
   pkill -P "$(< work/pid)"
 }
 
-# MIN -> COM
+wait_exit () {
+  set +e
+  wait "$(< work/pid)"
+  code="$?"
+  set -e
+  >&3 echo "Exited with exit code $code."
+  return "$code"
+}
+
+# * `COM`: Command exited
+# * `MAX`: Maximum lifetime exceeded
+# * `MIN`: Minimum lifetime exceeded
+# * `SIG`: SIGTERM received
+#
+# MIN -> COM -> MAX -> SIG
+# MIN -> COM -> SIG -> MAX
 @test "MIN -> COM" {
   measure -min-lifetime 2 -command test-bin/command-zero
-  wait
+  wait_exit
   [ "$(result)" == 4 ]
 }
 
-# COM -> MIN
-@test "COM -> MIN" {
+# COM -> MIN -> MAX -> SIG
+# COM -> MIN -> SIG -> MAX
+# COM -> SIG -> MIN -> MAX
+@test "COM" {
   measure -min-lifetime 6 -command test-bin/command-zero
-  wait
+  wait_exit
   [ "$(result)" == 4 ]
 }
 
-# SIG -> MIN
+# MIN -> MAX -> COM -> SIG
+# MIN -> MAX -> SIG -> COM
+@test "MIN -> MAX" {
+  measure -max-lifetime 2 -command test-bin/command-zero
+  wait
+  [ "$(result)" == 2 ]
+}
+
+# SIG -> MIN -> MAX -> COM
+# SIG -> MIN -> COM -> MAX
 @test "SIG -> MIN" {
   measure -min-lifetime 2 -command test-bin/command-zero
   sleep 1
@@ -56,11 +82,30 @@ sigterm () {
   [ "$(result)" == 2 ]
 }
 
-# MIN -> SIG
+# MIN -> SIG -> COM -> MAX
+# MIN -> SIG -> MAX -> COM
 @test "MIN -> SIG" {
   measure -min-lifetime 2 -command test-bin/command-zero
   sleep 3
   sigterm
   wait
   [ "$(result)" == 3 ]
 }
+
+# SIG -> COM -> MIN -> MAX
+@test "SIG -> COM" {
+  measure -min-lifetime 6 -command test-bin/command-zero
+  sleep 2
+  sigterm
+  wait
+  [ "$(result)" == 4 ]
+}
+
+# Invalid order
+@test "MAX -> MIN" {
+  measure -min-lifetime 4 -max-lifetime 2 -command test-bin/command-zero
+  if wait_exit; then
+    exit 1
+  fi
+  [ "$(result)" == 0 ]
+}