func run() int { lfd, err := common.GetRktLockFD() if err != nil { fmt.Fprintf(os.Stderr, "Failed to get rkt lock fd: %v\n", err) return 254 } if err := sys.CloseOnExec(lfd, true); err != nil { fmt.Fprintf(os.Stderr, "Failed to set FD_CLOEXEC on rkt lock: %v\n", err) return 254 } if err := stage1common.WritePid(os.Getpid(), "ppid"); err != nil { fmt.Fprintf(os.Stderr, "write ppid: %v", err) return 254 } fmt.Println("success, stub stage1 would at this point switch to stage2") return 0 }
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 }
func stage1() int { uuid, err := types.NewUUID(flag.Arg(0)) if err != nil { log.Print("UUID is missing or malformed\n") return 1 } root := "." p, err := stage1commontypes.LoadPod(root, uuid) if err != nil { log.PrintE("can't load pod", err) return 1 } // Sanity checks if len(p.Manifest.Apps) != 1 { log.Printf("flavor %q only supports 1 application per Pod for now", flavor) return 1 } ra := p.Manifest.Apps[0] imgName := p.AppNameToImageName(ra.Name) args := ra.App.Exec if len(args) == 0 { log.Printf(`image %q has an empty "exec" (try --exec=BINARY)`, imgName) return 1 } lfd, err := common.GetRktLockFD() if err != nil { log.PrintE("can't get rkt lock fd", err) return 1 } // set close-on-exec flag on RKT_LOCK_FD so it gets correctly closed after execution is finished if err := sys.CloseOnExec(lfd, true); err != nil { log.PrintE("can't set FD_CLOEXEC on rkt lock", err) return 1 } workDir := "/" if ra.App.WorkingDirectory != "" { workDir = ra.App.WorkingDirectory } env := []string{"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"} for _, e := range ra.App.Environment { env = append(env, e.Name+"="+e.Value) } rfs := filepath.Join(common.AppPath(p.Root, ra.Name), "rootfs") if err := copyResolv(p); err != nil { log.PrintE("can't copy /etc/resolv.conf", err) return 1 } argFlyMounts, err := evaluateMounts(rfs, string(ra.Name), p) if err != nil { log.PrintE("can't evaluate mounts", err) return 1 } effectiveMounts := append( []flyMount{ {"", "", "/dev", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/dev", rfs, "/dev", "none", syscall.MS_BIND | syscall.MS_REC}, {"", "", "/proc", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/proc", rfs, "/proc", "none", syscall.MS_BIND | syscall.MS_REC}, {"", "", "/sys", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/sys", rfs, "/sys", "none", syscall.MS_BIND | syscall.MS_REC}, {"tmpfs", rfs, "/tmp", "tmpfs", 0}, }, argFlyMounts..., ) for _, mount := range effectiveMounts { var ( err error hostPathInfo os.FileInfo targetPathInfo os.FileInfo ) if strings.HasPrefix(mount.HostPath, "/") { if hostPathInfo, err = os.Stat(mount.HostPath); err != nil { log.PrintE(fmt.Sprintf("stat of host path %s", mount.HostPath), err) return 1 } } else { hostPathInfo = nil } absTargetPath := filepath.Join(mount.TargetPrefixPath, mount.RelTargetPath) if targetPathInfo, err = os.Stat(absTargetPath); err != nil && !os.IsNotExist(err) { log.PrintE(fmt.Sprintf("stat of target path %s", absTargetPath), err) return 1 } switch { case targetPathInfo == nil: absTargetPathParent, _ := filepath.Split(absTargetPath) if err := os.MkdirAll(absTargetPathParent, 0755); err != nil { log.PrintE(fmt.Sprintf("can't create directory %q", absTargetPath), err) return 1 } switch { case hostPathInfo == nil || hostPathInfo.IsDir(): if err := os.Mkdir(absTargetPath, 0755); err != nil { log.PrintE(fmt.Sprintf("can't create directory %q", absTargetPath), err) return 1 } case !hostPathInfo.IsDir(): file, err := os.OpenFile(absTargetPath, os.O_CREATE, 0700) if err != nil { log.PrintE(fmt.Sprintf("can't create file %q", absTargetPath), err) return 1 } file.Close() } case hostPathInfo != nil: switch { case hostPathInfo.IsDir() && !targetPathInfo.IsDir(): log.Printf("can't mount because %q is a directory while %q is not", mount.HostPath, absTargetPath) return 1 case !hostPathInfo.IsDir() && targetPathInfo.IsDir(): log.Printf("can't mount because %q is not a directory while %q is", mount.HostPath, absTargetPath) return 1 } } if err := syscall.Mount(mount.HostPath, absTargetPath, mount.Fs, mount.Flags, ""); err != nil { log.PrintE(fmt.Sprintf("can't mount %q on %q with flags %v", mount.HostPath, absTargetPath, mount.Flags), err) return 1 } } if err = stage1common.WritePid(os.Getpid(), "pid"); err != nil { log.Error(err) return 1 } var uidResolver, gidResolver user.Resolver var uid, gid int uidResolver, err = user.NumericIDs(ra.App.User) if err != nil { uidResolver, err = user.IDsFromStat(rfs, ra.App.User, nil) } if err != nil { // give up log.PrintE(fmt.Sprintf("invalid user %q", ra.App.User), err) return 1 } if uid, _, err = uidResolver.IDs(); err != nil { log.PrintE(fmt.Sprintf("failed to configure user %q", ra.App.User), err) return 1 } gidResolver, err = user.NumericIDs(ra.App.Group) if err != nil { gidResolver, err = user.IDsFromStat(rfs, ra.App.Group, nil) } if err != nil { // give up log.PrintE(fmt.Sprintf("invalid group %q", ra.App.Group), err) return 1 } if _, gid, err = gidResolver.IDs(); err != nil { log.PrintE(fmt.Sprintf("failed to configure group %q", ra.App.Group), err) return 1 } diag.Printf("chroot to %q", rfs) if err := syscall.Chroot(rfs); err != nil { log.PrintE("can't chroot", err) return 1 } if err := os.Chdir(workDir); err != nil { log.PrintE(fmt.Sprintf("can't change to working directory %q", workDir), err) return 1 } // lock the current goroutine to its current OS thread. // This will force the subsequent syscalls to be executed in the same OS thread as Setresuid, and Setresgid, // see https://github.com/golang/go/issues/1435#issuecomment-66054163. runtime.LockOSThread() diag.Printf("setting uid %d gid %d", uid, gid) if err := syscall.Setresgid(gid, gid, gid); err != nil { log.PrintE(fmt.Sprintf("can't set gid %d", gid), err) return 1 } if err := syscall.Setresuid(uid, uid, uid); err != nil { log.PrintE(fmt.Sprintf("can't set uid %d", uid), err) return 1 } diag.Printf("execing %q in %q", args, rfs) err = stage1common.WithClearedCloExec(lfd, func() error { return syscall.Exec(args[0], args, env) }) if err != nil { log.PrintE(fmt.Sprintf("can't execute %q", args[0]), err) return 1 } return 0 }
func stage1() int { uuid, err := types.NewUUID(flag.Arg(0)) if err != nil { log.PrintE("UUID is missing or malformed", err) return 1 } root := "." p, err := stage1commontypes.LoadPod(root, uuid) if err != nil { log.PrintE("failed to load pod", err) return 1 } // 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.PrintE("failed to get rkt lock fd", err) return 1 } if err := sys.CloseOnExec(lfd, true); err != nil { log.PrintE("failed to set FD_CLOEXEC on rkt lock", err) return 1 } mirrorLocalZoneInfo(p.Root) flavor, _, err := stage1initcommon.GetFlavor(p) if err != nil { log.PrintE("failed to get stage1 flavor", err) return 1 } var n *networking.Networking if netList.Contained() { fps, err := forwardedPorts(p) if err != nil { log.Error(err) return 1 } n, err = networking.Setup(root, p.UUID, fps, netList, localConfig, flavor, debug) if err != nil { log.PrintE("failed to setup network", err) return 1 } if err = n.Save(); err != nil { log.PrintE("failed to save networking state", err) n.Teardown(flavor, debug) return 1 } if len(mdsToken) > 0 { hostIP, err := n.GetForwardableNetHostIP() if err != nil { log.PrintE("failed to get default Host IP", err) return 1 } p.MetadataServiceURL = common.MetadataServicePublicURL(hostIP, mdsToken) } } else { if flavor == "kvm" { log.Print("flavor kvm requires private network configuration (try --net)") return 1 } if len(mdsToken) > 0 { p.MetadataServiceURL = common.MetadataServicePublicURL(localhostIP, mdsToken) } } if err = stage1initcommon.WriteDefaultTarget(p); err != nil { log.PrintE("failed to write default.target", err) return 1 } if err = stage1initcommon.WritePrepareAppTemplate(p); err != nil { log.PrintE("failed to write prepare-app service template", err) return 1 } 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.PrintE("failed to configure systemd for kvm", err) return 1 } } insecureOptions := stage1initcommon.Stage1InsecureOptions{ DisablePaths: disablePaths, DisableCapabilities: disableCapabilities, DisableSeccomp: disableSeccomp, } if err = stage1initcommon.PodToSystemd(p, interactive, flavor, privateUsers, insecureOptions); err != nil { log.PrintE("failed to configure systemd", err) return 1 } args, env, err := getArgsEnv(p, flavor, debug, n, insecureOptions) if err != nil { log.Error(err) return 1 } // 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 := syscall.Mount("", "/", "none", syscall.MS_REC|syscall.MS_SLAVE, ""); err != nil { log.FatalE("error making / a slave mount", err) } if err := syscall.Mount("", "/", "none", syscall.MS_REC|syscall.MS_SHARED, ""); err != nil { log.FatalE("error making / a shared and slave mount", err) } enabledCgroups, err := cgroup.GetEnabledCgroups() if err != nil { log.FatalE("error getting cgroups", err) return 1 } if err := mountHostCgroups(enabledCgroups); err != nil { log.FatalE("couldn't mount the host cgroups", err) return 1 } var serviceNames []string for _, app := range p.Manifest.Apps { serviceNames = append(serviceNames, stage1initcommon.ServiceUnitName(app.Name)) } s1Root := common.Stage1RootfsPath(p.Root) machineID := stage1initcommon.GetMachineID(p) subcgroup, err := getContainerSubCgroup(machineID) if err == nil { if err := ioutil.WriteFile(filepath.Join(p.Root, "subcgroup"), []byte(fmt.Sprintf("%s", subcgroup)), 0644); err != nil { log.FatalE("cannot write subcgroup file", err) return 1 } if err := mountContainerCgroups(s1Root, enabledCgroups, subcgroup, serviceNames); err != nil { log.PrintE("couldn't mount the container cgroups", err) return 1 } } else { log.PrintE("continuing with per-app isolators disabled", 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.Error(err) return 1 } if flavor == "kvm" { if err := KvmPrepareMounts(s1Root, p); err != nil { log.PrintE("could not prepare mounts", err) return 1 } } err = stage1common.WithClearedCloExec(lfd, func() error { return syscall.Exec(args[0], args, env) }) if err != nil { log.PrintE(fmt.Sprintf("failed to execute %q", args[0]), err) return 1 } return 0 }
func stage1(rp *stage1commontypes.RuntimePod) int { uuid, err := types.NewUUID(flag.Arg(0)) if err != nil { log.Print("UUID is missing or malformed\n") return 254 } root := "." p, err := stage1commontypes.LoadPod(root, uuid, rp) if err != nil { log.PrintE("can't load pod", err) return 254 } if err := p.SaveRuntime(); err != nil { log.FatalE("failed to save runtime parameters", err) } // Sanity checks if len(p.Manifest.Apps) != 1 { log.Printf("flavor %q only supports 1 application per Pod for now", flavor) return 254 } ra := p.Manifest.Apps[0] imgName := p.AppNameToImageName(ra.Name) args := ra.App.Exec if len(args) == 0 { log.Printf(`image %q has an empty "exec" (try --exec=BINARY)`, imgName) return 254 } lfd, err := common.GetRktLockFD() if err != nil { log.PrintE("can't get rkt lock fd", err) return 254 } // set close-on-exec flag on RKT_LOCK_FD so it gets correctly closed after execution is finished if err := sys.CloseOnExec(lfd, true); err != nil { log.PrintE("can't set FD_CLOEXEC on rkt lock", err) return 254 } workDir := "/" if ra.App.WorkingDirectory != "" { workDir = ra.App.WorkingDirectory } env := []string{"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"} for _, e := range ra.App.Environment { env = append(env, e.Name+"="+e.Value) } rfs := filepath.Join(common.AppPath(p.Root, ra.Name), "rootfs") argFlyMounts, err := evaluateMounts(rfs, string(ra.Name), p) if err != nil { log.PrintE("can't evaluate mounts", err) return 254 } effectiveMounts := append( []flyMount{ {"", "", "/dev", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/dev", rfs, "/dev", "none", syscall.MS_BIND | syscall.MS_REC}, {"", "", "/proc", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/proc", rfs, "/proc", "none", syscall.MS_BIND | syscall.MS_REC}, {"", "", "/sys", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/sys", rfs, "/sys", "none", syscall.MS_BIND | syscall.MS_REC}, {"tmpfs", rfs, "/tmp", "tmpfs", 0}, }, argFlyMounts..., ) /* Process DNS config files * * /etc/resolv.conf: four modes * 'host' - bind-mount host's file * 'stage0' - bind-mount the file created by stage0 * 'default' - do nothing (we would respect CNI if fly had networking) * 'none' - do nothing */ switch p.ResolvConfMode { case "host": effectiveMounts = append(effectiveMounts, flyMount{"/etc/resolv.conf", rfs, "/etc/resolv.conf", "none", syscall.MS_BIND | syscall.MS_RDONLY}) case "stage0": if err := copyResolv(p); err != nil { log.PrintE("can't copy /etc/resolv.conf", err) return 254 } } /* * /etc/hosts: three modes: * 'host' - bind-mount hosts's file * 'stage0' - bind mount the file created by stage1 * 'default' - create a stub /etc/hosts if needed */ switch p.EtcHostsMode { case "host": effectiveMounts = append(effectiveMounts, flyMount{"/etc/hosts", rfs, "/etc/hosts", "none", syscall.MS_BIND | syscall.MS_RDONLY}) case "stage0": effectiveMounts = append(effectiveMounts, flyMount{ filepath.Join(common.Stage1RootfsPath(p.Root), "etc", "rkt-hosts"), rfs, "/etc/hosts", "none", syscall.MS_BIND | syscall.MS_RDONLY}) case "default": stage2HostsPath := filepath.Join(common.AppRootfsPath(p.Root, ra.Name), "etc", "hosts") if _, err := os.Stat(stage2HostsPath); err != nil && os.IsNotExist(err) { fallbackHosts := []byte("127.0.0.1 localhost localdomain\n") ioutil.WriteFile(stage2HostsPath, fallbackHosts, 0644) } } for _, mount := range effectiveMounts { diag.Printf("Processing %+v", mount) var ( err error hostPathInfo os.FileInfo targetPathInfo os.FileInfo ) if strings.HasPrefix(mount.HostPath, "/") { if hostPathInfo, err = os.Stat(mount.HostPath); err != nil { log.PrintE(fmt.Sprintf("stat of host path %s", mount.HostPath), err) return 254 } } else { hostPathInfo = nil } absTargetPath := filepath.Join(mount.TargetPrefixPath, mount.RelTargetPath) if targetPathInfo, err = os.Stat(absTargetPath); err != nil && !os.IsNotExist(err) { log.PrintE(fmt.Sprintf("stat of target path %s", absTargetPath), err) return 254 } switch { case (mount.Flags & syscall.MS_REMOUNT) != 0: { diag.Printf("don't attempt to create files for remount of %q", absTargetPath) } case targetPathInfo == nil: absTargetPathParent, _ := filepath.Split(absTargetPath) if err := os.MkdirAll(absTargetPathParent, 0755); err != nil { log.PrintE(fmt.Sprintf("can't create directory %q", absTargetPath), err) return 254 } switch { case hostPathInfo == nil || hostPathInfo.IsDir(): if err := os.Mkdir(absTargetPath, 0755); err != nil { log.PrintE(fmt.Sprintf("can't create directory %q", absTargetPath), err) return 254 } case !hostPathInfo.IsDir(): file, err := os.OpenFile(absTargetPath, os.O_CREATE, 0700) if err != nil { log.PrintE(fmt.Sprintf("can't create file %q", absTargetPath), err) return 254 } file.Close() } case hostPathInfo != nil: switch { case hostPathInfo.IsDir() && !targetPathInfo.IsDir(): log.Printf("can't mount because %q is a directory while %q is not", mount.HostPath, absTargetPath) return 254 case !hostPathInfo.IsDir() && targetPathInfo.IsDir(): log.Printf("can't mount because %q is not a directory while %q is", mount.HostPath, absTargetPath) return 254 } } if err := syscall.Mount(mount.HostPath, absTargetPath, mount.Fs, mount.Flags, ""); err != nil { log.PrintE(fmt.Sprintf("can't mount %q on %q with flags %v", mount.HostPath, absTargetPath, mount.Flags), err) return 254 } } if err = stage1common.WritePid(os.Getpid(), "pid"); err != nil { log.Error(err) return 254 } var uidResolver, gidResolver user.Resolver var uid, gid int uidResolver, err = user.NumericIDs(ra.App.User) if err != nil { uidResolver, err = user.IDsFromStat(rfs, ra.App.User, nil) } if err != nil { // give up log.PrintE(fmt.Sprintf("invalid user %q", ra.App.User), err) return 254 } if uid, _, err = uidResolver.IDs(); err != nil { log.PrintE(fmt.Sprintf("failed to configure user %q", ra.App.User), err) return 254 } gidResolver, err = user.NumericIDs(ra.App.Group) if err != nil { gidResolver, err = user.IDsFromStat(rfs, ra.App.Group, nil) } if err != nil { // give up log.PrintE(fmt.Sprintf("invalid group %q", ra.App.Group), err) return 254 } if _, gid, err = gidResolver.IDs(); err != nil { log.PrintE(fmt.Sprintf("failed to configure group %q", ra.App.Group), err) return 254 } diag.Printf("chroot to %q", rfs) if err := syscall.Chroot(rfs); err != nil { log.PrintE("can't chroot", err) return 254 } if err := os.Chdir(workDir); err != nil { log.PrintE(fmt.Sprintf("can't change to working directory %q", workDir), err) return 254 } // lock the current goroutine to its current OS thread. // This will force the subsequent syscalls to be executed in the same OS thread as Setresuid, and Setresgid, // see https://github.com/golang/go/issues/1435#issuecomment-66054163. runtime.LockOSThread() diag.Printf("setting uid %d gid %d", uid, gid) if err := syscall.Setresgid(gid, gid, gid); err != nil { log.PrintE(fmt.Sprintf("can't set gid %d", gid), err) return 254 } if err := syscall.Setresuid(uid, uid, uid); err != nil { log.PrintE(fmt.Sprintf("can't set uid %d", uid), err) return 254 } diag.Printf("execing %q in %q", args, rfs) err = stage1common.WithClearedCloExec(lfd, func() error { return syscall.Exec(args[0], args, env) }) if err != nil { log.PrintE(fmt.Sprintf("can't execute %q", args[0]), err) return 254 } return 0 }
func stage1() int { uuid, err := types.NewUUID(flag.Arg(0)) if err != nil { log.Print("UUID is missing or malformed\n") return 1 } root := "." p, err := stage1commontypes.LoadPod(root, uuid) if err != nil { log.PrintE("can't load pod", err) return 1 } // Sanity checks if len(p.Manifest.Apps) != 1 { log.Printf("flavor %q only supports 1 application per Pod for now", flavor) return 1 } ra := p.Manifest.Apps[0] imgName := p.AppNameToImageName(ra.Name) args := ra.App.Exec if len(args) == 0 { log.Printf(`image %q has an empty "exec" (try --exec=BINARY)`, imgName) return 1 } lfd, err := common.GetRktLockFD() if err != nil { log.PrintE("can't get rkt lock fd", err) return 1 } // set close-on-exec flag on RKT_LOCK_FD so it gets correctly closed after execution is finished if err := sys.CloseOnExec(lfd, true); err != nil { log.PrintE("can't set FD_CLOEXEC on rkt lock", err) return 1 } workDir := "/" if ra.App.WorkingDirectory != "" { workDir = ra.App.WorkingDirectory } env := []string{"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"} for _, e := range ra.App.Environment { env = append(env, e.Name+"="+e.Value) } rfs := filepath.Join(common.AppPath(p.Root, ra.Name), "rootfs") argFlyMounts, err := evaluateMounts(rfs, string(ra.Name), p) if err != nil { log.PrintE("can't evaluate mounts", err) return 1 } effectiveMounts := append( []flyMount{ {"", "", "/dev", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/dev", rfs, "/dev", "none", syscall.MS_BIND | syscall.MS_REC}, {"", "", "/proc", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/proc", rfs, "/proc", "none", syscall.MS_BIND | syscall.MS_REC}, {"", "", "/sys", "none", syscall.MS_REC | syscall.MS_SHARED}, {"/sys", rfs, "/sys", "none", syscall.MS_BIND | syscall.MS_REC}, {"tmpfs", rfs, "/tmp", "tmpfs", 0}, }, argFlyMounts..., ) for _, mount := range effectiveMounts { var ( err error hostPathInfo os.FileInfo targetPathInfo os.FileInfo ) if strings.HasPrefix(mount.HostPath, "/") { if hostPathInfo, err = os.Stat(mount.HostPath); err != nil { log.PrintE(fmt.Sprintf("stat of host path %s", mount.HostPath), err) return 1 } } else { hostPathInfo = nil } absTargetPath := filepath.Join(mount.TargetPrefixPath, mount.RelTargetPath) if targetPathInfo, err = os.Stat(absTargetPath); err != nil && !os.IsNotExist(err) { log.PrintE(fmt.Sprintf("stat of target path %s", absTargetPath), err) return 1 } switch { case targetPathInfo == nil: absTargetPathParent, _ := filepath.Split(absTargetPath) if err := os.MkdirAll(absTargetPathParent, 0700); err != nil { log.PrintE(fmt.Sprintf("can't create directory %q", absTargetPath), err) return 1 } switch { case hostPathInfo == nil || hostPathInfo.IsDir(): if err := os.Mkdir(absTargetPath, 0700); err != nil { log.PrintE(fmt.Sprintf("can't create directory %q", absTargetPath), err) return 1 } case !hostPathInfo.IsDir(): file, err := os.OpenFile(absTargetPath, os.O_CREATE, 0700) if err != nil { log.PrintE(fmt.Sprintf("can't create file %q", absTargetPath), err) return 1 } file.Close() } case hostPathInfo != nil: switch { case hostPathInfo.IsDir() && !targetPathInfo.IsDir(): log.Printf("can't mount because %q is a directory while %q is not", mount.HostPath, absTargetPath) return 1 case !hostPathInfo.IsDir() && targetPathInfo.IsDir(): log.Printf("can't mount because %q is not a directory while %q is", mount.HostPath, absTargetPath) return 1 } } if err := syscall.Mount(mount.HostPath, absTargetPath, mount.Fs, mount.Flags, ""); err != nil { log.PrintE(fmt.Sprintf("can't mount %q on %q with flags %v", mount.HostPath, absTargetPath, mount.Flags), err) return 1 } } if err = stage1common.WritePid(os.Getpid(), "ppid"); err != nil { log.Error(err) return 1 } diag.Printf("chroot to %q", rfs) if err := syscall.Chroot(rfs); err != nil { log.PrintE("can't chroot", err) return 1 } if err := os.Chdir(workDir); err != nil { log.PrintE(fmt.Sprintf("can't change to working directory %q", workDir), err) return 1 } diag.Printf("execing %q in %q", args, rfs) err = stage1common.WithClearedCloExec(lfd, func() error { return syscall.Exec(args[0], args, env) }) if err != nil { log.PrintE(fmt.Sprintf("can't execute %q", args[0]), err) return 1 } return 0 }