Working test

.gitignore

@@ -1,6 +1,9 @@
 runsvinit
 runsvinit-*-*
 examples/runsvinit-linux-amd64*
+zombietest/zombie
+zombietest/runsvinit
+*.uptodate
 
 # Compiled Object files, Static and Dynamic libs (Shared Objects)
 *.o

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"log"
 	"os"
 	"os/exec"
@@ -13,6 +14,9 @@ import (
 const etcService = "/etc/service"
 
 func main() {
+	reap := flag.Bool("reap", true, "reap orphan children")
+	flag.Parse()
+
 	log.SetFlags(0)
 
 	runsvdir, err := exec.LookPath("runsvdir")
@@ -35,7 +39,12 @@ func main() {
 		log.Printf("warning: I'm not PID 1, I'm PID %d", pid)
 	}
 
-	go reapAll()
+	if *reap {
+		log.Print("reaping zombies")
+		go reapLoop()
+	} else {
+		log.Print("NOT reaping zombies")
+	}
 
 	supervisor := cmd(runsvdir, etcService)
 	if err := supervisor.Start(); err != nil {
@@ -53,16 +62,17 @@ func main() {
 	}
 }
 
-func reapAll() {
+// From https://github.com/ramr/go-reaper/blob/master/reaper.go
+func reapLoop() {
 	c := make(chan os.Signal)
 	signal.Notify(c, syscall.SIGCHLD)
 	for range c {
-		go reapOne()
+		reapChildren()
 	}
 }
 
-// From https://github.com/ramr/go-reaper/blob/master/reaper.go
-func reapOne() {
+func reapChildren() {
+	for {
 		var (
 			ws  syscall.WaitStatus
 			pid int
@@ -75,10 +85,11 @@ func reapOne() {
 			}
 		}
 		if err == syscall.ECHILD {
-		return
+			return // done
 		}
 		log.Printf("reaped child process %d (%+v)", pid, ws)
 	}
+}
 
 type signaler interface {
 	Signal(os.Signal) error

zombietest/Dockerfile

@@ -0,0 +1,11 @@
+FROM alpine:latest
+RUN echo "http://dl-4.alpinelinux.org/alpine/edge/testing" >>/etc/apk/repositories && \
+    apk add --update runit && \
+    rm -rf /var/cache/apk/*
+
+COPY zombie /
+RUN mkdir -p /etc/service/zombie
+COPY run-zombie /etc/service/zombie/run
+
+COPY /runsvinit /
+

zombietest/Makefile

@@ -0,0 +1,23 @@
+.PHONY: test clean
+
+test: .test.uptodate
+	./test.bash
+
+.test.uptodate: runsvinit zombie run-zombie Dockerfile
+	docker build -t zombietest .
+	touch $@
+
+runsvinit: ../*.go
+	env GOOS=linux GOARCH=amd64 go build -o $@ github.com/peterbourgon/runsvinit
+
+zombie: .build.uptodate
+	docker run --rm -v $(shell pwd):/mount zombietest-build cc -Wall -Werror -o /mount/zombie /zombie.c
+
+.build.uptodate: build/zombie.c build/Dockerfile
+	docker build -t zombietest-build build/
+	touch $@
+
+clean:
+	rm -rf .test.uptodate .build.uptodate runsvinit zombie
+	docker stop zombietest zombietest-build >/dev/null 2>&1 || true
+	docker rm zombietest zombietest-build >/dev/null 2>&1 || true

zombietest/README.md

@@ -0,0 +1,24 @@
+# zombietest
+
+This directory contains an integration test to prove runsvinit is actually
+reaping zombies. `make` builds and executes the test as follows:
+
+1. We produce a linux/amd64 runsvinit binary by setting GOOS/GOARCH and
+   invoking the Go compiler. Requires Go 1.5, or Go 1.4 built with the
+   appropriate cross-compile options.
+
+2. The build/zombie.c program spawns five zombies and exits. We compile it for
+   linux/amd64 via a zombietest-build container. We do this so `make` works
+   from a Mac. This requires a working Docker installation.
+
+3. Once we have linux/amd64 runsvinit and zombie binaries, we produce a
+   zombietest container via the Dockerfile. That container contains a single
+   runit service, /etc/service/zombie, which supervises the zombie binary. We
+   provide no default ENTRYPOINT, so we can supply it at runtime.
+
+4. Once the zombietest container is built, we invoke the test.bash script.
+   That launches a version of the container with runsvinit set to NOT reap
+   zombies, and after 1 second, verifies that zombies exist. Then, it launches
+   a version of the container with runsvinit set to reap zombies, and after 1
+   second, verifies that no zombies exist.
+

zombietest/build/Dockerfile

@@ -1,9 +1,3 @@
-FROM golang:1.5.1
-
-COPY ../../*.go /go/src/github.com/peterbourgon/runsvinit
-RUN go install -v github.com/peterbourgon/runsvinit
-RUN mv /go/bin/runsvinit /mount/
-
+FROM alpine:latest
+RUN apk add --update gcc musl-dev && rm -rf /var/cache/apk/*
 COPY zombie.c /
-RUN cc -Wall -Werror -o /zombie /zombie.c
-RUN mv /zombie /mount/

zombietest/build/Makefile

@@ -1,9 +0,0 @@
-.PHONY: all
-all: zombie runsvinit
-
-zombie runsvinit: .uptodate
-	docker run -ti --rm -v $(shell pwd):/mount zombie-build
-
-.uptodate: Dockerfile ../../*.go
-	docker build -t zombie-build .
-	touch $@

zombietest/build/zombie.c

@@ -1,18 +1,18 @@
 #include <stdlib.h>
-#include <sys/types.h>
+#include <stdio.h>
 #include <unistd.h>
 
-int main ()
-{
-  pid_t child_pid;
-
-  child_pid = fork ();
-  if (child_pid > 0) {
-    sleep (60);
-  }
-  else {
+int main() {
+        pid_t pid;
+        int i; 
+        for (i = 0; i<5; i++)  {  
+                pid = fork();
+                if (pid > 0) {
+                        printf("Zombie #%d born\n", i + 1);
+                } else {
+                        printf("Brains...\n");
                         exit(0);
                 }  
+        }  
         return 0; 
 }
-

zombietest/run-zombie

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+exec /zombie

zombietest/test.bash

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+RC=0
+SLEEP=1
+
+C=$(docker run -d zombietest /runsvinit -reap=false)
+sleep $SLEEP
+NOREAP=$(docker exec $C ps -o pid,stat | grep Z | wc -l)
+echo -n without reaping, we have $NOREAP zombies...
+if [ "$NOREAP" -le "0" ]
+then
+	echo " FAIL"
+	RC=1
+else
+	echo " good"
+fi
+docker stop $C >/dev/null
+docker rm $C >/dev/null
+
+C=$(docker run -d zombietest /runsvinit)
+sleep $SLEEP
+YESREAP=$(docker exec $C ps -o pid,stat | grep Z | wc -l)
+echo -n with reaping, we have $YESREAP zombies...
+if [ "$YESREAP" -gt "0" ]
+then
+	echo " FAIL"
+	RC=1
+else
+	echo " good"
+fi
+docker stop $C >/dev/null
+docker rm $C >/dev/null
+
+exit $RC