Compare commits
No commits in common. "master" and "v2.0.0" have entirely different histories.
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@ -1,9 +1,6 @@
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runsvinit
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runsvinit-*-*
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examples/runsvinit-linux-amd64*
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zombietest/zombie
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zombietest/runsvinit
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*.uptodate
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# Compiled Object files, Static and Dynamic libs (Shared Objects)
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*.o
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34
README.md
34
README.md
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@ -1,27 +1,19 @@
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# runsvinit [](https://circleci.com/gh/peterbourgon/runsvinit)
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# runsvinit
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If you have a Docker container that's a collection of runit-supervised daemons, this process is suitable for use as the ENTRYPOINT.
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If you have a Docker container that's a collection of runit-supervised daemons,
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this process is suitable for use as the ENTRYPOINT.
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See [the example](https://github.com/peterbourgon/runsvinit/tree/master/example).
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**Why not use runit(8) directly?**
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**Why not just exec runsvdir?**
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[runit(8)](http://smarden.org/runit/runit.8.html) is designed to be used as process 1.
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And, if you provide an `/etc/service/ctrlaltdel` script, it will be executed when runit receives the INT signal.
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So, we could use that hook to gracefully terminate our services.
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But Docker only sends TERM on `docker stop`.
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`docker stop` issues SIGTERM (or, in a future version of Docker, perhaps another custom signal)
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but if runsvdir receives a signal,
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it doesn't wait for its supervised processes to exit before returning.
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If you don't care about graceful shutdown of your daemons, no problem, you don't need this tool.
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Note that the container stop signal [will become configurable](https://github.com/docker/docker/pull/15307) in Docker 1.9.
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Once Docker 1.9 ships, this utility will be obsolete.
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**Why not wrap runsvdir in a simple shell script?**
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**Why not just exec runsvdir(8) directly?**
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If [runsvdir(8)](http://smarden.org/runit/runsvdir.8.html) receives a signal, it doesn't wait for its supervised processes to exit before returning.
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**Why not wrap runsvdir(8) in a simple shell script?**
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Process 1 has the additional responsibility of [reaping orphaned child processes](https://blog.phusion.nl/2015/01/20/docker-and-the-pid-1-zombie-reaping-problem/).
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To the best of my knowledge, there is no sane way to do this with a shell script.
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Otherwise, indeed, this would work great:
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This works great:
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```sh
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#!/bin/sh
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@ -38,10 +30,14 @@ trap "sv_stop; exit" SIGTERM
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wait
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```
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...except it doesn't [reap orphaned child processes](https://blog.phusion.nl/2015/01/20/docker-and-the-pid-1-zombie-reaping-problem/)
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and is therefore unsuitable for being PID 1.
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**Why not use my_init from [phusion/baseimage-docker](https://github.com/phusion/baseimage-docker)?**
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my_init depends on Python 3, which might be a big dependency for such a small responsibility.
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That works great — if you're willing to add python3 to your Docker images :)
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**So this is just a stripped-down my_init in Go?**
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Basically, yes.
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@ -1,8 +0,0 @@
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machine:
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services:
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- docker
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test:
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override:
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- go test -v
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- make CIRCLECI=true SUDO=sudo RMCONTAINER= -C zombietest
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@ -2,9 +2,9 @@
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docker: runsvinit
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docker build -t runsvinit-example .
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runsvinit: $GOPATH/bin/runsvinit
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cp $< $@
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runsvinit: runsvinit-linux-amd64.tgz
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tar zxf $<
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$GOPATH/bin/runsvinit:
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go get -u github.com/peterbourgon/runsvinit
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runsvinit-linux-amd64.tgz:
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wget --quiet https://github.com/peterbourgon/runsvinit/releases/download/v2.0.0/runsvinit-linux-amd64.tgz
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97
main.go
97
main.go
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@ -1,93 +1,68 @@
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package main
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import (
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"flag"
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"log"
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"os"
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"os/exec"
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"os/signal"
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"path/filepath"
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"strings"
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"sync"
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"syscall"
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)
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const etcService = "/etc/service"
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var (
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debugf = log.Printf
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info = log.Print
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infof = log.Printf
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fatal = log.Fatal
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fatalf = log.Fatalf
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)
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func main() {
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var (
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reap = flag.Bool("reap", true, "reap orphan children")
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debug = flag.Bool("debug", false, "log debug information")
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)
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flag.Parse()
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log.SetFlags(0)
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if !*debug {
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debugf = func(string, ...interface{}) {}
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}
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runsvdir, err := exec.LookPath("runsvdir")
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if err != nil {
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fatal(err)
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log.Fatal(err)
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}
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sv, err := exec.LookPath("sv")
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if err != nil {
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fatal(err)
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log.Fatal(err)
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}
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if fi, err := os.Stat(etcService); err != nil {
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fatal(err)
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log.Fatal(err)
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} else if !fi.IsDir() {
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fatalf("%s is not a directory", etcService)
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log.Fatalf("%s is not a directory", etcService)
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}
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if pid := os.Getpid(); pid != 1 {
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debugf("warning: I'm not PID 1, I'm PID %d", pid)
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log.Printf("warning: I'm not PID 1, I'm PID %d", pid)
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}
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if *reap {
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go reapLoop()
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} else {
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infof("warning: NOT reaping zombies")
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}
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go reapAll()
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supervisor := cmd(runsvdir, etcService)
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if err := supervisor.Start(); err != nil {
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fatal(err)
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log.Fatal(err)
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}
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debugf("%s started", runsvdir)
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log.Printf("%s started", runsvdir)
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go shutdown(sv, supervisor.Process)
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if err := supervisor.Wait(); err != nil {
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infof("%s exited with error: %v", runsvdir, err)
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log.Printf("%s exited with error: %v", runsvdir, err)
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} else {
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debugf("%s exited cleanly", runsvdir)
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log.Printf("%s exited cleanly", runsvdir)
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}
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}
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func reapAll() {
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c := make(chan os.Signal)
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signal.Notify(c, syscall.SIGCHLD)
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for range c {
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go reapOne()
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}
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}
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// From https://github.com/ramr/go-reaper/blob/master/reaper.go
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func reapLoop() {
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c := make(chan os.Signal)
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signal.Notify(c, syscall.SIGCHLD)
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for range c {
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reapChildren()
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}
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}
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func reapChildren() {
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for {
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func reapOne() {
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var (
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ws syscall.WaitStatus
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pid int
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@ -100,10 +75,9 @@ func reapChildren() {
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}
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}
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if err == syscall.ECHILD {
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return // done
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}
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infof("reaped child process %d (%+v)", pid, ws)
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return
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}
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log.Printf("reaped child process %d (%+v)", pid, ws)
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}
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type signaler interface {
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@ -114,45 +88,40 @@ func shutdown(sv string, s signaler) {
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c := make(chan os.Signal)
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signal.Notify(c, syscall.SIGTERM, syscall.SIGINT)
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sig := <-c
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debugf("received %s", sig)
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log.Printf("received %s", sig)
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matches, err := filepath.Glob(filepath.Join(etcService, "*"))
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if err != nil {
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infof("when shutting down services: %v", err)
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log.Printf("when shutting down services: %v", err)
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return
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}
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var wg sync.WaitGroup
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var stopped []string
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for _, match := range matches {
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fi, err := os.Stat(match)
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if err != nil {
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infof("%s: %v", match, err)
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log.Printf("%s: %v", match, err)
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continue
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}
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if !fi.IsDir() {
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infof("%s: not a directory", match)
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log.Printf("%s: not a directory", match)
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continue
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}
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service := filepath.Base(match)
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stop := cmd(sv, "stop", service)
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debugf("stopping %s...", service)
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wg.Add(1)
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go func() {
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defer wg.Done()
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if err := stop.Run(); err != nil {
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infof("%s: %v", strings.Join(stop.Args, " "), err)
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} else {
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debugf("stopped %s", service)
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log.Printf("%s: %v", strings.Join(stop.Args, " "), err)
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continue
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}
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}()
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stopped = append(stopped, service)
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}
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wg.Wait()
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debugf("stopping supervisor with signal %s...", sig)
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log.Printf("stopped %d: %s", len(stopped), strings.Join(stopped, ", "))
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log.Printf("stopping supervisor with signal %s...", sig)
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if err := s.Signal(sig); err != nil {
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info(err)
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log.Print(err)
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}
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debugf("shutdown handler exiting")
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log.Printf("shutdown handler exiting")
|
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}
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func cmd(path string, args ...string) *exec.Cmd {
|
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|
|
|
|||
|
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@ -1,11 +0,0 @@
|
|||
FROM alpine:latest
|
||||
RUN echo "http://dl-4.alpinelinux.org/alpine/edge/testing" >>/etc/apk/repositories && \
|
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apk add --update runit && \
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rm -rf /var/cache/apk/*
|
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|
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COPY zombie /
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RUN mkdir -p /etc/service/zombie
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||||
COPY run-zombie /etc/service/zombie/run
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||||
COPY /runsvinit /
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|
|
@ -1,27 +0,0 @@
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|||
GO ?= go
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SUDO ?=
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RMCONTAINER ?= --rm
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||||
|
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.PHONY: test clean
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||||
|
||||
test: .test.uptodate
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||||
./test.bash
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||||
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.test.uptodate: runsvinit zombie run-zombie Dockerfile
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$(SUDO) docker build -t zombietest .
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touch $@
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runsvinit: ../*.go
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env GOOS=linux GOARCH=amd64 $(GO) build -o $@ github.com/peterbourgon/runsvinit
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zombie: .build.uptodate
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$(SUDO) docker run $(RMCONTAINER) -v $(shell pwd):/mount zombietest-build cc -Wall -Werror -o /mount/zombie /zombie.c
|
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|
||||
.build.uptodate: build/zombie.c build/Dockerfile
|
||||
$(SUDO) docker build -t zombietest-build build/
|
||||
touch $@
|
||||
|
||||
clean:
|
||||
rm -rf .test.uptodate .build.uptodate runsvinit zombie
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$(SUDO) docker stop zombietest zombietest-build >/dev/null 2>&1 || true
|
||||
$(SUDO) docker rm zombietest zombietest-build >/dev/null 2>&1 || true
|
||||
|
|
@ -1,24 +0,0 @@
|
|||
# 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.
|
||||
|
||||
|
|
@ -1,3 +0,0 @@
|
|||
FROM alpine:latest
|
||||
RUN apk add --update gcc musl-dev && rm -rf /var/cache/apk/*
|
||||
COPY zombie.c /
|
||||
|
|
@ -1,18 +0,0 @@
|
|||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <unistd.h>
|
||||
|
||||
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;
|
||||
}
|
||||
|
|
@ -1,3 +0,0 @@
|
|||
#!/bin/sh
|
||||
|
||||
exec /zombie
|
||||
|
|
@ -1,48 +0,0 @@
|
|||
#!/bin/bash
|
||||
|
||||
function zombies() {
|
||||
if [ -z "$CIRCLECI" ]
|
||||
then
|
||||
docker exec $C ps -o pid,stat | grep Z | wc -l
|
||||
else
|
||||
# https://circleci.com/docs/docker#docker-exec
|
||||
sudo lxc-attach -n "$(docker inspect --format '{{.Id}}' $C)" -- sh -c "ps -o pid,stat | grep Z | wc -l"
|
||||
fi
|
||||
}
|
||||
|
||||
function stop_rm() {
|
||||
docker stop $1 >/dev/null
|
||||
#docker logs $1
|
||||
docker rm $1 >/dev/null
|
||||
}
|
||||
|
||||
SLEEP=1
|
||||
RC=0
|
||||
|
||||
C=$(docker run -d zombietest /runsvinit -reap=false -debug)
|
||||
sleep $SLEEP
|
||||
NOREAP=$(zombies)
|
||||
echo -n without reaping, we have $NOREAP zombies...
|
||||
if [ "$NOREAP" -le "0" ]
|
||||
then
|
||||
echo " FAIL"
|
||||
RC=1
|
||||
else
|
||||
echo " good"
|
||||
fi
|
||||
stop_rm $C
|
||||
|
||||
C=$(docker run -d zombietest /runsvinit -debug)
|
||||
sleep $SLEEP
|
||||
YESREAP=$(zombies)
|
||||
echo -n with reaping, we have $YESREAP zombies...
|
||||
if [ "$YESREAP" -gt "0" ]
|
||||
then
|
||||
echo " FAIL"
|
||||
RC=1
|
||||
else
|
||||
echo " good"
|
||||
fi
|
||||
stop_rm $C
|
||||
|
||||
exit $RC
|
||||
Loading…
Reference in New Issue