package server import ( "encoding/json" "errors" "fmt" "io" "os" "path/filepath" "strconv" "strings" "syscall" "time" "github.com/Sirupsen/logrus" "github.com/docker/docker/pkg/symlink" "github.com/kubernetes-incubator/cri-o/oci" "github.com/kubernetes-incubator/cri-o/pkg/annotations" "github.com/kubernetes-incubator/cri-o/server/apparmor" "github.com/kubernetes-incubator/cri-o/server/seccomp" "github.com/opencontainers/image-spec/specs-go/v1" "github.com/opencontainers/runc/libcontainer/cgroups" "github.com/opencontainers/runc/libcontainer/devices" "github.com/opencontainers/runc/libcontainer/user" rspec "github.com/opencontainers/runtime-spec/specs-go" "github.com/opencontainers/runtime-tools/generate" "github.com/opencontainers/selinux/go-selinux/label" "golang.org/x/net/context" pb "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime" ) const ( seccompUnconfined = "unconfined" seccompRuntimeDefault = "runtime/default" seccompLocalhostPrefix = "localhost/" ) func addOCIBindMounts(sb *sandbox, containerConfig *pb.ContainerConfig, specgen *generate.Generator) error { mounts := containerConfig.GetMounts() for _, mount := range mounts { dest := mount.ContainerPath if dest == "" { return fmt.Errorf("Mount.ContainerPath is empty") } src := mount.HostPath if src == "" { return fmt.Errorf("Mount.HostPath is empty") } if _, err := os.Stat(src); err != nil && os.IsNotExist(err) { if err1 := os.MkdirAll(src, 0644); err1 != nil { return fmt.Errorf("Failed to mkdir %s: %s", src, err) } } options := []string{"rw"} if mount.Readonly { options = []string{"ro"} } if mount.SelinuxRelabel { // Need a way in kubernetes to determine if the volume is shared or private if err := label.Relabel(src, sb.mountLabel, true); err != nil && err != syscall.ENOTSUP { return fmt.Errorf("relabel failed %s: %v", src, err) } } specgen.AddBindMount(src, dest, options) } return nil } func addDevices(sb *sandbox, containerConfig *pb.ContainerConfig, specgen *generate.Generator) error { sp := specgen.Spec() for _, device := range containerConfig.GetDevices() { dev, err := devices.DeviceFromPath(device.HostPath, device.Permissions) if err != nil { return fmt.Errorf("failed to add device: %v", err) } rd := rspec.LinuxDevice{ Path: device.ContainerPath, Type: string(dev.Type), Major: dev.Major, Minor: dev.Minor, UID: &dev.Uid, GID: &dev.Gid, } specgen.AddDevice(rd) sp.Linux.Resources.Devices = append(sp.Linux.Resources.Devices, rspec.LinuxDeviceCgroup{ Allow: true, Type: string(dev.Type), Major: &dev.Major, Minor: &dev.Minor, Access: dev.Permissions, }) } return nil } // buildOCIProcessArgs build an OCI compatible process arguments slice. func buildOCIProcessArgs(containerKubeConfig *pb.ContainerConfig, imageOCIConfig *v1.Image) ([]string, error) { //# Start the nginx container using the default command, but use custom //arguments (arg1 .. argN) for that command. //kubectl run nginx --image=nginx -- ... //# Start the nginx container using a different command and custom arguments. //kubectl run nginx --image=nginx --command -- ... kubeCommands := containerKubeConfig.Command kubeArgs := containerKubeConfig.Args // merge image config and kube config // same as docker does today... if imageOCIConfig != nil { if len(kubeCommands) == 0 { if len(kubeArgs) == 0 { kubeArgs = imageOCIConfig.Config.Cmd } if kubeCommands == nil { kubeCommands = imageOCIConfig.Config.Entrypoint } } } if len(kubeCommands) == 0 && len(kubeArgs) == 0 { return nil, fmt.Errorf("no command specified") } // create entrypoint and args var entrypoint string var args []string if len(kubeCommands) != 0 { entrypoint = kubeCommands[0] args = append(kubeCommands[1:], kubeArgs...) } else { entrypoint = kubeArgs[0] args = kubeArgs[1:] } processArgs := append([]string{entrypoint}, args...) logrus.Debugf("OCI process args %v", processArgs) return processArgs, nil } // setupContainerUser sets the UID, GID and supplemental groups in OCI runtime config func setupContainerUser(specgen *generate.Generator, rootfs string, sc *pb.LinuxContainerSecurityContext, imageConfig *v1.Image) error { if sc != nil { containerUser := "" // Case 1: run as user is set by kubelet if sc.RunAsUser != nil { containerUser = strconv.FormatInt(sc.GetRunAsUser().Value, 10) } else { // Case 2: run as username is set by kubelet userName := sc.RunAsUsername if userName != "" { containerUser = userName } else { // Case 3: get user from image config if imageConfig != nil { imageUser := imageConfig.Config.User if imageUser != "" { containerUser = imageUser } } } } logrus.Debugf("CONTAINER USER: %+v", containerUser) // Add uid, gid and groups from user uid, gid, addGroups, err1 := getUserInfo(rootfs, containerUser) if err1 != nil { return err1 } logrus.Debugf("UID: %v, GID: %v, Groups: %+v", uid, gid, addGroups) specgen.SetProcessUID(uid) specgen.SetProcessGID(gid) for _, group := range addGroups { specgen.AddProcessAdditionalGid(group) } // Add groups from CRI groups := sc.SupplementalGroups for _, group := range groups { specgen.AddProcessAdditionalGid(uint32(group)) } } return nil } func hostNetwork(containerConfig *pb.ContainerConfig) bool { securityContext := containerConfig.GetLinux().GetSecurityContext() if securityContext == nil || securityContext.GetNamespaceOptions() == nil { return false } return securityContext.GetNamespaceOptions().HostNetwork } // ensureSaneLogPath is a hack to fix https://issues.k8s.io/44043 which causes // logPath to be a broken symlink to some magical Docker path. Ideally we // wouldn't have to deal with this, but until that issue is fixed we have to // remove the path if it's a broken symlink. func ensureSaneLogPath(logPath string) error { // If the path exists but the resolved path does not, then we have a broken // symlink and we need to remove it. fi, err := os.Lstat(logPath) if err != nil || fi.Mode()&os.ModeSymlink == 0 { // Non-existant files and non-symlinks aren't our problem. return nil } _, err = os.Stat(logPath) if os.IsNotExist(err) { err = os.RemoveAll(logPath) if err != nil { return fmt.Errorf("ensureSaneLogPath remove bad logPath: %s", err) } } return nil } // CreateContainer creates a new container in specified PodSandbox func (s *Server) CreateContainer(ctx context.Context, req *pb.CreateContainerRequest) (res *pb.CreateContainerResponse, err error) { logrus.Debugf("CreateContainerRequest %+v", req) s.updateLock.RLock() defer s.updateLock.RUnlock() sbID := req.PodSandboxId if sbID == "" { return nil, fmt.Errorf("PodSandboxId should not be empty") } sandboxID, err := s.podIDIndex.Get(sbID) if err != nil { return nil, fmt.Errorf("PodSandbox with ID starting with %s not found: %v", sbID, err) } sb := s.getSandbox(sandboxID) if sb == nil { return nil, fmt.Errorf("specified sandbox not found: %s", sandboxID) } // The config of the container containerConfig := req.GetConfig() if containerConfig == nil { return nil, fmt.Errorf("CreateContainerRequest.ContainerConfig is nil") } name := containerConfig.GetMetadata().Name if name == "" { return nil, fmt.Errorf("CreateContainerRequest.ContainerConfig.Name is empty") } containerID, containerName, err := s.generateContainerIDandName(sb.metadata, containerConfig) if err != nil { return nil, err } defer func() { if err != nil { s.releaseContainerName(containerName) } }() container, err := s.createSandboxContainer(ctx, containerID, containerName, sb, req.GetSandboxConfig(), containerConfig) if err != nil { return nil, err } defer func() { if err != nil { err2 := s.storageRuntimeServer.DeleteContainer(containerID) if err2 != nil { logrus.Warnf("Failed to cleanup container directory: %v", err2) } } }() if err = s.runtime.CreateContainer(container, sb.cgroupParent); err != nil { return nil, err } if err = s.runtime.UpdateStatus(container); err != nil { return nil, err } s.addContainer(container) if err = s.ctrIDIndex.Add(containerID); err != nil { s.removeContainer(container) return nil, err } s.containerStateToDisk(container) resp := &pb.CreateContainerResponse{ ContainerId: containerID, } logrus.Debugf("CreateContainerResponse: %+v", resp) return resp, nil } func (s *Server) createSandboxContainer(ctx context.Context, containerID string, containerName string, sb *sandbox, SandboxConfig *pb.PodSandboxConfig, containerConfig *pb.ContainerConfig) (*oci.Container, error) { if sb == nil { return nil, errors.New("createSandboxContainer needs a sandbox") } // TODO: simplify this function (cyclomatic complexity here is high) // TODO: factor generating/updating the spec into something other projects can vendor // creates a spec Generator with the default spec. specgen := generate.New() specgen.HostSpecific = true specgen.ClearProcessRlimits() if err := addOCIBindMounts(sb, containerConfig, &specgen); err != nil { return nil, err } // Add cgroup mount so container process can introspect its own limits specgen.AddCgroupsMount("ro") if err := addDevices(sb, containerConfig, &specgen); err != nil { return nil, err } labels := containerConfig.GetLabels() metadata := containerConfig.GetMetadata() kubeAnnotations := containerConfig.GetAnnotations() if kubeAnnotations != nil { for k, v := range kubeAnnotations { specgen.AddAnnotation(k, v) } } // set this container's apparmor profile if it is set by sandbox if s.appArmorEnabled { appArmorProfileName := s.getAppArmorProfileName(sb.annotations, metadata.Name) if appArmorProfileName != "" { // reload default apparmor profile if it is unloaded. if s.appArmorProfile == apparmor.DefaultApparmorProfile { if err := apparmor.EnsureDefaultApparmorProfile(); err != nil { return nil, err } } specgen.SetProcessApparmorProfile(appArmorProfileName) } } var readOnlyRootfs bool if containerConfig.GetLinux().GetSecurityContext() != nil { if containerConfig.GetLinux().GetSecurityContext().Privileged { specgen.SetupPrivileged(true) } if containerConfig.GetLinux().GetSecurityContext().ReadonlyRootfs { readOnlyRootfs = true specgen.SetRootReadonly(true) } } logPath := containerConfig.LogPath if logPath == "" { // TODO: Should we use sandboxConfig.GetLogDirectory() here? logPath = filepath.Join(sb.logDir, containerID+".log") } if !filepath.IsAbs(logPath) { // XXX: It's not really clear what this should be versus the sbox logDirectory. logrus.Warnf("requested logPath for ctr id %s is a relative path: %s", containerID, logPath) logPath = filepath.Join(sb.logDir, logPath) } // Handle https://issues.k8s.io/44043 if err := ensureSaneLogPath(logPath); err != nil { return nil, err } logrus.WithFields(logrus.Fields{ "sbox.logdir": sb.logDir, "ctr.logfile": containerConfig.LogPath, "log_path": logPath, }).Debugf("setting container's log_path") specgen.SetProcessTerminal(containerConfig.Tty) linux := containerConfig.GetLinux() if linux != nil { resources := linux.GetResources() if resources != nil { cpuPeriod := resources.CpuPeriod if cpuPeriod != 0 { specgen.SetLinuxResourcesCPUPeriod(uint64(cpuPeriod)) } cpuQuota := resources.CpuQuota if cpuQuota != 0 { specgen.SetLinuxResourcesCPUQuota(cpuQuota) } cpuShares := resources.CpuShares if cpuShares != 0 { specgen.SetLinuxResourcesCPUShares(uint64(cpuShares)) } memoryLimit := resources.MemoryLimitInBytes if memoryLimit != 0 { specgen.SetLinuxResourcesMemoryLimit(uint64(memoryLimit)) } oomScoreAdj := resources.OomScoreAdj specgen.SetLinuxResourcesOOMScoreAdj(int(oomScoreAdj)) } if sb.cgroupParent != "" { if s.config.CgroupManager == "systemd" { cgPath := sb.cgroupParent + ":" + "crio" + ":" + containerID specgen.SetLinuxCgroupsPath(cgPath) } else { specgen.SetLinuxCgroupsPath(sb.cgroupParent + "/" + containerID) } } capabilities := linux.GetSecurityContext().GetCapabilities() toCAPPrefixed := func(cap string) string { if !strings.HasPrefix(strings.ToLower(cap), "cap_") { return "CAP_" + cap } return cap } if capabilities != nil { addCaps := capabilities.AddCapabilities if addCaps != nil { for _, cap := range addCaps { if err := specgen.AddProcessCapability(toCAPPrefixed(cap)); err != nil { return nil, err } } } dropCaps := capabilities.DropCapabilities if dropCaps != nil { for _, cap := range dropCaps { if err := specgen.DropProcessCapability(toCAPPrefixed(cap)); err != nil { logrus.Debugf("failed to drop cap %s: %v", toCAPPrefixed(cap), err) } } } } specgen.SetProcessSelinuxLabel(sb.processLabel) specgen.SetLinuxMountLabel(sb.mountLabel) if containerConfig.GetLinux().GetSecurityContext() != nil && !containerConfig.GetLinux().GetSecurityContext().Privileged { for _, mp := range []string{ "/proc/kcore", "/proc/latency_stats", "/proc/timer_list", "/proc/timer_stats", "/proc/sched_debug", "/sys/firmware", } { specgen.AddLinuxMaskedPaths(mp) } for _, rp := range []string{ "/proc/asound", "/proc/bus", "/proc/fs", "/proc/irq", "/proc/sys", "/proc/sysrq-trigger", } { specgen.AddLinuxReadonlyPaths(rp) } } } // Join the namespace paths for the pod sandbox container. podInfraState := s.runtime.ContainerStatus(sb.infraContainer) logrus.Debugf("pod container state %+v", podInfraState) ipcNsPath := fmt.Sprintf("/proc/%d/ns/ipc", podInfraState.Pid) if err := specgen.AddOrReplaceLinuxNamespace("ipc", ipcNsPath); err != nil { return nil, err } netNsPath := sb.netNsPath() if netNsPath == "" { // The sandbox does not have a permanent namespace, // it's on the host one. netNsPath = fmt.Sprintf("/proc/%d/ns/net", podInfraState.Pid) } if err := specgen.AddOrReplaceLinuxNamespace("network", netNsPath); err != nil { return nil, err } imageSpec := containerConfig.GetImage() if imageSpec == nil { return nil, fmt.Errorf("CreateContainerRequest.ContainerConfig.Image is nil") } image := imageSpec.Image if image == "" { return nil, fmt.Errorf("CreateContainerRequest.ContainerConfig.Image.Image is empty") } // bind mount the pod shm specgen.AddBindMount(sb.shmPath, "/dev/shm", []string{"rw"}) options := []string{"rw"} if readOnlyRootfs { options = []string{"ro"} } if sb.resolvPath != "" { // bind mount the pod resolver file specgen.AddBindMount(sb.resolvPath, "/etc/resolv.conf", options) } // Bind mount /etc/hosts for host networking containers if hostNetwork(containerConfig) { specgen.AddBindMount("/etc/hosts", "/etc/hosts", options) } if sb.hostname != "" { specgen.SetHostname(sb.hostname) } specgen.AddAnnotation(annotations.Name, containerName) specgen.AddAnnotation(annotations.ContainerID, containerID) specgen.AddAnnotation(annotations.SandboxID, sb.id) specgen.AddAnnotation(annotations.SandboxName, sb.infraContainer.Name()) specgen.AddAnnotation(annotations.ContainerType, annotations.ContainerTypeContainer) specgen.AddAnnotation(annotations.LogPath, logPath) specgen.AddAnnotation(annotations.TTY, fmt.Sprintf("%v", containerConfig.Tty)) specgen.AddAnnotation(annotations.Stdin, fmt.Sprintf("%v", containerConfig.Stdin)) specgen.AddAnnotation(annotations.StdinOnce, fmt.Sprintf("%v", containerConfig.StdinOnce)) specgen.AddAnnotation(annotations.Image, image) created := time.Now() specgen.AddAnnotation(annotations.Created, created.Format(time.RFC3339Nano)) metadataJSON, err := json.Marshal(metadata) if err != nil { return nil, err } specgen.AddAnnotation(annotations.Metadata, string(metadataJSON)) labelsJSON, err := json.Marshal(labels) if err != nil { return nil, err } specgen.AddAnnotation(annotations.Labels, string(labelsJSON)) kubeAnnotationsJSON, err := json.Marshal(kubeAnnotations) if err != nil { return nil, err } specgen.AddAnnotation(annotations.Annotations, string(kubeAnnotationsJSON)) if err = s.setupSeccomp(&specgen, containerName, sb.annotations); err != nil { return nil, err } metaname := metadata.Name attempt := metadata.Attempt containerInfo, err := s.storageRuntimeServer.CreateContainer(s.imageContext, sb.name, sb.id, image, image, containerName, containerID, metaname, attempt, sb.mountLabel, nil) if err != nil { return nil, err } mountPoint, err := s.storageRuntimeServer.StartContainer(containerID) if err != nil { return nil, fmt.Errorf("failed to mount container %s(%s): %v", containerName, containerID, err) } containerImageConfig := containerInfo.Config if containerImageConfig == nil { return nil, fmt.Errorf("empty image config for %s", image) } if containerImageConfig.Config.StopSignal != "" { // this key is defined in image-spec conversion document at https://github.com/opencontainers/image-spec/pull/492/files#diff-8aafbe2c3690162540381b8cdb157112R57 specgen.AddAnnotation("org.opencontainers.image.stopSignal", containerImageConfig.Config.StopSignal) } // TODO: volume handling in CRI-O // right now, we do just an mkdir in the container rootfs because we // know kube manages volumes its own way and we don't need to behave // like docker. // For instance gcr.io/k8s-testimages/redis:e2e now work with CRI-O for dest := range containerImageConfig.Config.Volumes { fp, err := symlink.FollowSymlinkInScope(filepath.Join(mountPoint, dest), mountPoint) if err != nil { return nil, err } switch s.config.ImageVolumes { case ImageVolumesMkdir: if err1 := os.MkdirAll(fp, 0644); err1 != nil { return nil, err1 } case ImageVolumesIgnore: logrus.Debugf("Ignoring volume %v", dest) default: logrus.Fatalf("Unrecognized image volumes setting") } } processArgs, err := buildOCIProcessArgs(containerConfig, containerImageConfig) if err != nil { return nil, err } specgen.SetProcessArgs(processArgs) // Add environment variables from CRI and image config envs := containerConfig.GetEnvs() if envs != nil { for _, item := range envs { key := item.Key value := item.Value if key == "" { continue } specgen.AddProcessEnv(key, value) } } if containerImageConfig != nil { for _, item := range containerImageConfig.Config.Env { parts := strings.SplitN(item, "=", 2) if len(parts) != 2 { return nil, fmt.Errorf("invalid env from image: %s", item) } if parts[0] == "" { continue } specgen.AddProcessEnv(parts[0], parts[1]) } } // Set working directory // Pick it up from image config first and override if specified in CRI containerCwd := "/" if containerImageConfig != nil { imageCwd := containerImageConfig.Config.WorkingDir if imageCwd != "" { containerCwd = imageCwd } } runtimeCwd := containerConfig.WorkingDir if runtimeCwd != "" { containerCwd = runtimeCwd } specgen.SetProcessCwd(containerCwd) // Setup user and groups if linux != nil { if err = setupContainerUser(&specgen, mountPoint, linux.GetSecurityContext(), containerImageConfig); err != nil { return nil, err } } // Set up pids limit if pids cgroup is mounted _, err = cgroups.FindCgroupMountpoint("pids") if err == nil { specgen.SetLinuxResourcesPidsLimit(s.config.PidsLimit) } // by default, the root path is an empty string. set it now. specgen.SetRootPath(mountPoint) saveOptions := generate.ExportOptions{} if err = specgen.SaveToFile(filepath.Join(containerInfo.Dir, "config.json"), saveOptions); err != nil { return nil, err } if err = specgen.SaveToFile(filepath.Join(containerInfo.RunDir, "config.json"), saveOptions); err != nil { return nil, err } container, err := oci.NewContainer(containerID, containerName, containerInfo.RunDir, logPath, sb.netNs(), labels, kubeAnnotations, imageSpec, metadata, sb.id, containerConfig.Tty, containerConfig.Stdin, containerConfig.StdinOnce, sb.privileged, sb.trusted, containerInfo.Dir, created, containerImageConfig.Config.StopSignal) if err != nil { return nil, err } return container, nil } func (s *Server) setupSeccomp(specgen *generate.Generator, cname string, sbAnnotations map[string]string) error { profile, ok := sbAnnotations["security.alpha.kubernetes.io/seccomp/container/"+cname] if !ok { profile, ok = sbAnnotations["security.alpha.kubernetes.io/seccomp/pod"] if !ok { // running w/o seccomp, aka unconfined profile = seccompUnconfined } } if !s.seccompEnabled { if profile != seccompUnconfined { return fmt.Errorf("seccomp is not enabled in your kernel, cannot run with a profile") } logrus.Warn("seccomp is not enabled in your kernel, running container without profile") } if profile == seccompUnconfined { // running w/o seccomp, aka unconfined specgen.Spec().Linux.Seccomp = nil return nil } if profile == seccompRuntimeDefault { return seccomp.LoadProfileFromStruct(s.seccompProfile, specgen) } if !strings.HasPrefix(profile, seccompLocalhostPrefix) { return fmt.Errorf("unknown seccomp profile option: %q", profile) } //file, err := ioutil.ReadFile(filepath.Join(s.seccompProfileRoot, strings.TrimPrefix(profile, seccompLocalhostPrefix))) //if err != nil { //return err //} // TODO(runcom): setup from provided node's seccomp profile // can't do this yet, see https://issues.k8s.io/36997 return nil } // getAppArmorProfileName gets the profile name for the given container. func (s *Server) getAppArmorProfileName(annotations map[string]string, ctrName string) string { profile := apparmor.GetProfileNameFromPodAnnotations(annotations, ctrName) if profile == "" { return "" } if profile == apparmor.ProfileRuntimeDefault { // If the value is runtime/default, then return default profile. return s.appArmorProfile } return strings.TrimPrefix(profile, apparmor.ProfileNamePrefix) } // openContainerFile opens a file inside a container rootfs safely func openContainerFile(rootfs string, path string) (io.ReadCloser, error) { fp, err := symlink.FollowSymlinkInScope(filepath.Join(rootfs, path), rootfs) if err != nil { return nil, err } return os.Open(fp) } // getUserInfo returns UID, GID and additional groups for specified user // by looking them up in /etc/passwd and /etc/group func getUserInfo(rootfs string, userName string) (uint32, uint32, []uint32, error) { // We don't care if we can't open the file because // not all images will have these files passwdFile, err := openContainerFile(rootfs, "/etc/passwd") if err != nil { logrus.Warnf("Failed to open /etc/passwd: %v", err) } else { defer passwdFile.Close() } groupFile, err := openContainerFile(rootfs, "/etc/group") if err != nil { logrus.Warnf("Failed to open /etc/group: %v", err) } else { defer groupFile.Close() } execUser, err := user.GetExecUser(userName, nil, passwdFile, groupFile) if err != nil { return 0, 0, nil, err } uid := uint32(execUser.Uid) gid := uint32(execUser.Gid) var additionalGids []uint32 for _, g := range execUser.Sgids { additionalGids = append(additionalGids, uint32(g)) } return uid, gid, additionalGids, nil }