// prepareAppCgroups makes the cgroups-v1 hierarchy for this application writable
// by pod supervisor
func prepareAppCgroups(p *stage1types.Pod, ra *schema.RuntimeApp, enterCmd []string) error {
isUnified, err := cgroup.IsCgroupUnified("/")
if err != nil {
return errwrap.Wrap(errors.New("failed to determine cgroup version"), err)
}
if isUnified {
return nil
}
enabledCgroups, err := v1.GetEnabledCgroups()
if err != nil {
return errwrap.Wrap(errors.New("error getting cgroups"), err)
}
b, err := ioutil.ReadFile(filepath.Join(p.Root, "subcgroup"))
if err != nil {
log.PrintE("continuing with per-app isolators disabled", err)
return nil
}
subcgroup := string(b)
serviceName := stage1initcommon.ServiceUnitName(ra.Name)
if err := v1.RemountCgroupKnobsRW(enabledCgroups, subcgroup, serviceName, enterCmd); err != nil {
return errwrap.Wrap(errors.New("error restricting application cgroups"), err)
}
return nil
}
func stage1() int {
uuid, err := types.NewUUID(flag.Arg(0))
if err != nil {
log.FatalE("UUID is missing or malformed", err)
}
root := "."
p, err := stage1commontypes.LoadPod(root, uuid)
if err != nil {
log.FatalE("failed to load pod", err)
}
// set close-on-exec flag on RKT_LOCK_FD so it gets correctly closed when invoking
// network plugins
lfd, err := common.GetRktLockFD()
if err != nil {
log.FatalE("failed to get rkt lock fd", err)
}
if err := sys.CloseOnExec(lfd, true); err != nil {
log.FatalE("failed to set FD_CLOEXEC on rkt lock", err)
}
mirrorLocalZoneInfo(p.Root)
flavor, _, err := stage1initcommon.GetFlavor(p)
if err != nil {
log.FatalE("failed to get stage1 flavor", err)
}
var n *networking.Networking
if netList.Contained() {
fps, err := commonnet.ForwardedPorts(p.Manifest)
if err != nil {
log.FatalE("error initializing forwarding ports", err)
}
noDNS := dnsConfMode.Pairs["resolv"] != "default" // force ignore CNI DNS results
n, err = networking.Setup(root, p.UUID, fps, netList, localConfig, flavor, noDNS, debug)
if err != nil {
log.FatalE("failed to setup network", err)
}
if err = n.Save(); err != nil {
log.PrintE("failed to save networking state", err)
n.Teardown(flavor, debug)
return 254
}
if len(mdsToken) > 0 {
hostIP, err := n.GetForwardableNetHostIP()
if err != nil {
log.FatalE("failed to get default Host IP", err)
}
p.MetadataServiceURL = common.MetadataServicePublicURL(hostIP, mdsToken)
}
} else {
if flavor == "kvm" {
log.Fatal("flavor kvm requires private network configuration (try --net)")
}
if len(mdsToken) > 0 {
p.MetadataServiceURL = common.MetadataServicePublicURL(localhostIP, mdsToken)
}
}
insecureOptions := stage1initcommon.Stage1InsecureOptions{
DisablePaths: disablePaths,
DisableCapabilities: disableCapabilities,
DisableSeccomp: disableSeccomp,
}
mnt := fs.NewLoggingMounter(
fs.MounterFunc(syscall.Mount),
fs.UnmounterFunc(syscall.Unmount),
diag.Printf,
)
if dnsConfMode.Pairs["resolv"] == "host" {
stage1initcommon.UseHostResolv(mnt, root)
}
if dnsConfMode.Pairs["hosts"] == "host" {
stage1initcommon.UseHostHosts(mnt, root)
}
if mutable {
if err = stage1initcommon.MutableEnv(p); err != nil {
log.FatalE("cannot initialize mutable environment", err)
}
} else {
if err = stage1initcommon.ImmutableEnv(p, interactive, privateUsers, insecureOptions); err != nil {
log.FatalE("cannot initialize immutable environment", err)
}
}
if err := stage1initcommon.SetJournalPermissions(p); err != nil {
log.PrintE("warning: error setting journal ACLs, you'll need root to read the pod journal", err)
}
if flavor == "kvm" {
kvm.InitDebug(debug)
if err := KvmNetworkingToSystemd(p, n); err != nil {
log.FatalE("failed to configure systemd for kvm", err)
}
}
canMachinedRegister := false
if flavor != "kvm" {
// kvm doesn't register with systemd right now, see #2664.
canMachinedRegister = machinedRegister()
}
diag.Printf("canMachinedRegister %t", canMachinedRegister)
args, env, err := getArgsEnv(p, flavor, canMachinedRegister, debug, n, insecureOptions)
if err != nil {
log.FatalE("cannot get environment", err)
}
diag.Printf("args %q", args)
diag.Printf("env %q", env)
// create a separate mount namespace so the cgroup filesystems
// are unmounted when exiting the pod
if err := syscall.Unshare(syscall.CLONE_NEWNS); err != nil {
log.FatalE("error unsharing", err)
}
// we recursively make / a "shared and slave" so mount events from the
// new namespace don't propagate to the host namespace but mount events
// from the host propagate to the new namespace and are forwarded to
// its peer group
// See https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt
if err := mnt.Mount("", "/", "none", syscall.MS_REC|syscall.MS_SLAVE, ""); err != nil {
log.FatalE("error making / a slave mount", err)
}
if err := mnt.Mount("", "/", "none", syscall.MS_REC|syscall.MS_SHARED, ""); err != nil {
log.FatalE("error making / a shared and slave mount", err)
}
unifiedCgroup, err := cgroup.IsCgroupUnified("/")
if err != nil {
log.FatalE("error determining cgroup version", err)
}
diag.Printf("unifiedCgroup %t", unifiedCgroup)
s1Root := common.Stage1RootfsPath(p.Root)
machineID := stage1initcommon.GetMachineID(p)
subcgroup, err := getContainerSubCgroup(machineID, canMachinedRegister, unifiedCgroup)
if err != nil {
log.FatalE("error getting container subcgroup", err)
}
diag.Printf("subcgroup %q", subcgroup)
if err := ioutil.WriteFile(filepath.Join(p.Root, "subcgroup"),
[]byte(fmt.Sprintf("%s", subcgroup)), 0644); err != nil {
log.FatalE("cannot write subcgroup file", err)
}
if !unifiedCgroup {
enabledCgroups, err := v1.GetEnabledCgroups()
if err != nil {
log.FatalE("error getting v1 cgroups", err)
}
diag.Printf("enabledCgroups %q", enabledCgroups)
if err := mountHostV1Cgroups(mnt, enabledCgroups); err != nil {
log.FatalE("couldn't mount the host v1 cgroups", err)
}
if !canMachinedRegister {
if err := v1.JoinSubcgroup("systemd", subcgroup); err != nil {
log.FatalE(fmt.Sprintf("error joining subcgroup %q", subcgroup), err)
}
}
var serviceNames []string
for _, app := range p.Manifest.Apps {
serviceNames = append(serviceNames, stage1initcommon.ServiceUnitName(app.Name))
}
diag.Printf("serviceNames %q", serviceNames)
if err := mountContainerV1Cgroups(mnt, s1Root, enabledCgroups, subcgroup, serviceNames, insecureOptions); err != nil {
log.FatalE("couldn't mount the container v1 cgroups", err)
}
}
// KVM flavor has a bit different logic in handling pid vs ppid, for details look into #2389
// it doesn't require the existence of a "ppid", instead it registers the current pid (which
// will be reused by lkvm binary) as a pod process pid used during entering
pid_filename := "ppid"
if flavor == "kvm" {
pid_filename = "pid"
}
if err = stage1common.WritePid(os.Getpid(), pid_filename); err != nil {
log.FatalE("error writing pid", err)
}
if flavor == "kvm" {
if err := KvmPrepareMounts(s1Root, p); err != nil {
log.FatalE("error preparing mounts", err)
}
}
err = stage1common.WithClearedCloExec(lfd, func() error {
return syscall.Exec(args[0], args, env)
})
if err != nil {
log.FatalE(fmt.Sprintf("failed to execute %q", args[0]), err)
}
return 0
}