diff options
| -rw-r--r-- | libpod/networking_linux.go | 24 | ||||
| -rw-r--r-- | pkg/rootlessport/rootlessport_linux.go | 35 | ||||
| -rw-r--r-- | test/system/500-networking.bats | 3 |
3 files changed, 32 insertions, 30 deletions
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go index 8e9b5997c..7eef04ddf 100644 --- a/libpod/networking_linux.go +++ b/libpod/networking_linux.go @@ -173,11 +173,27 @@ func (r *RootlessCNI) Do(toRun func() error) error { // the link target will be available in the mount ns. // see: https://github.com/containers/podman/issues/10855 resolvePath := "/etc/resolv.conf" - resolvePath, err = filepath.EvalSymlinks(resolvePath) - if err != nil { - return err + for i := 0; i < 255; i++ { + // Do not use filepath.EvalSymlinks, we only want the first symlink under /run. + // If /etc/resolv.conf has more than one symlink under /run, e.g. + // -> /run/systemd/resolve/stub-resolv.conf -> /run/systemd/resolve/resolv.conf + // we would put the netns resolv.conf file to the last path. However this will + // break dns because the second link does not exists in the mount ns. + // see https://github.com/containers/podman/issues/11222 + link, err := os.Readlink(resolvePath) + if err != nil { + // if there is no symlink exit + break + } + resolvePath = filepath.Join(filepath.Dir(resolvePath), link) + if strings.HasPrefix(resolvePath, "/run/") { + break + } + if i == 254 { + return errors.New("too many symlinks while resolving /etc/resolv.conf") + } } - logrus.Debugf("The actual path of /etc/resolv.conf on the host is %q", resolvePath) + logrus.Debugf("The path of /etc/resolv.conf in the mount ns is %q", resolvePath) // When /etc/resolv.conf on the host is a symlink to /run/systemd/resolve/stub-resolv.conf, // we have to mount an empty filesystem on /run/systemd/resolve in the child namespace, // so as to isolate the directory from the host mount namespace. diff --git a/pkg/rootlessport/rootlessport_linux.go b/pkg/rootlessport/rootlessport_linux.go index ede216bfe..9a2f93f8e 100644 --- a/pkg/rootlessport/rootlessport_linux.go +++ b/pkg/rootlessport/rootlessport_linux.go @@ -20,7 +20,6 @@ import ( "net" "os" "os/exec" - "os/signal" "path/filepath" "github.com/containernetworking/plugins/pkg/ns" @@ -106,30 +105,6 @@ func parent() error { return err } - exitC := make(chan os.Signal, 1) - defer close(exitC) - - go func() { - sigC := make(chan os.Signal, 1) - signal.Notify(sigC, unix.SIGPIPE) - defer func() { - signal.Stop(sigC) - close(sigC) - }() - - select { - case s := <-sigC: - if s == unix.SIGPIPE { - if f, err := os.OpenFile("/dev/null", os.O_WRONLY, 0755); err == nil { - unix.Dup2(int(f.Fd()), 1) // nolint:errcheck - unix.Dup2(int(f.Fd()), 2) // nolint:errcheck - f.Close() - } - } - case <-exitC: - } - }() - socketDir := filepath.Join(cfg.TmpDir, "rp") err = os.MkdirAll(socketDir, 0700) if err != nil { @@ -251,8 +226,16 @@ outer: go serve(socket, driver) } - // write and close ReadyFD (convention is same as slirp4netns --ready-fd) logrus.Info("ready") + + // https://github.com/containers/podman/issues/11248 + // Copy /dev/null to stdout and stderr to prevent SIGPIPE errors + if f, err := os.OpenFile("/dev/null", os.O_WRONLY, 0755); err == nil { + unix.Dup2(int(f.Fd()), 1) // nolint:errcheck + unix.Dup2(int(f.Fd()), 2) // nolint:errcheck + f.Close() + } + // write and close ReadyFD (convention is same as slirp4netns --ready-fd) if _, err := readyW.Write([]byte("1")); err != nil { return err } diff --git a/test/system/500-networking.bats b/test/system/500-networking.bats index 6ffee7eaf..3ebe45e63 100644 --- a/test/system/500-networking.bats +++ b/test/system/500-networking.bats @@ -210,6 +210,9 @@ load helpers $IMAGE nc -l -n -v -p $myport cid="$output" + # check that dns is working inside the container + run_podman exec $cid nslookup google.com + # emit random string, and check it teststring=$(random_string 30) echo "$teststring" | nc 127.0.0.1 $myport |