diff options
| -rw-r--r-- | libpod/networking_slirp4netns.go | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/libpod/networking_slirp4netns.go b/libpod/networking_slirp4netns.go index 690f0c1fa..cc44f78f7 100644 --- a/libpod/networking_slirp4netns.go +++ b/libpod/networking_slirp4netns.go @@ -13,6 +13,7 @@ import ( "path/filepath" "strconv" "strings" + "sync" "syscall" "time" @@ -302,11 +303,15 @@ func (r *Runtime) setupSlirp4netns(ctr *Container, netns ns.NetNS) error { cmd.Stdout = logFile cmd.Stderr = logFile - var slirpReadyChan (chan struct{}) - + var slirpReadyWg, netnsReadyWg *sync.WaitGroup if netOptions.enableIPv6 { - slirpReadyChan = make(chan struct{}) - defer close(slirpReadyChan) + // use two wait groups to make sure we set the sysctl before + // starting slirp and reset it only after slirp is ready + slirpReadyWg = &sync.WaitGroup{} + netnsReadyWg = &sync.WaitGroup{} + slirpReadyWg.Add(1) + netnsReadyWg.Add(1) + go func() { err := ns.WithNetNSPath(netnsPath, func(_ ns.NetNS) error { // Duplicate Address Detection slows the ipv6 setup down for 1-2 seconds. @@ -318,23 +323,37 @@ func (r *Runtime) setupSlirp4netns(ctr *Container, netns ns.NetNS) error { // is ready in case users rely on this sysctl. orgValue, err := ioutil.ReadFile(ipv6ConfDefaultAcceptDadSysctl) if err != nil { + netnsReadyWg.Done() + // on ipv6 disabled systems the sysctl does not exists + // so we should not error + if errors.Is(err, os.ErrNotExist) { + return nil + } return err } err = ioutil.WriteFile(ipv6ConfDefaultAcceptDadSysctl, []byte("0"), 0644) + netnsReadyWg.Done() if err != nil { return err } - // wait for slirp to finish setup - <-slirpReadyChan + + // wait until slirp4nets is ready before reseting this value + slirpReadyWg.Wait() return ioutil.WriteFile(ipv6ConfDefaultAcceptDadSysctl, orgValue, 0644) }) if err != nil { logrus.Warnf("failed to set net.ipv6.conf.default.accept_dad sysctl: %v", err) } }() + + // wait until we set the sysctl + netnsReadyWg.Wait() } if err := cmd.Start(); err != nil { + if netOptions.enableIPv6 { + slirpReadyWg.Done() + } return errors.Wrapf(err, "failed to start slirp4netns process") } defer func() { @@ -344,11 +363,12 @@ func (r *Runtime) setupSlirp4netns(ctr *Container, netns ns.NetNS) error { } }() - if err := waitForSync(syncR, cmd, logFile, 1*time.Second); err != nil { - return err + err = waitForSync(syncR, cmd, logFile, 1*time.Second) + if netOptions.enableIPv6 { + slirpReadyWg.Done() } - if slirpReadyChan != nil { - slirpReadyChan <- struct{}{} + if err != nil { + return err } // Set a default slirp subnet. Parsing a string with the net helper is easier than building the struct myself |