package libpod import ( "fmt" "io" "io/ioutil" "os" "path/filepath" "strings" "syscall" "time" "github.com/containers/storage" "github.com/containers/storage/pkg/archive" "github.com/docker/docker/pkg/mount" "github.com/docker/docker/pkg/namesgenerator" "github.com/docker/docker/pkg/stringid" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/opencontainers/selinux/go-selinux/label" "github.com/pkg/errors" "github.com/sirupsen/logrus" "github.com/ulule/deepcopier" "golang.org/x/sys/unix" ) const ( // name of the directory holding the artifacts artifactsDir = "artifacts" ) // rootFsSize gets the size of the container's root filesystem // A container FS is split into two parts. The first is the top layer, a // mutable layer, and the rest is the RootFS: the set of immutable layers // that make up the image on which the container is based. func (c *Container) rootFsSize() (int64, error) { container, err := c.runtime.store.Container(c.ID()) if err != nil { return 0, err } // Ignore the size of the top layer. The top layer is a mutable RW layer // and is not considered a part of the rootfs rwLayer, err := c.runtime.store.Layer(container.LayerID) if err != nil { return 0, err } layer, err := c.runtime.store.Layer(rwLayer.Parent) if err != nil { return 0, err } size := int64(0) for layer.Parent != "" { layerSize, err := c.runtime.store.DiffSize(layer.Parent, layer.ID) if err != nil { return size, errors.Wrapf(err, "getting diffsize of layer %q and its parent %q", layer.ID, layer.Parent) } size += layerSize layer, err = c.runtime.store.Layer(layer.Parent) if err != nil { return 0, err } } // Get the size of the last layer. Has to be outside of the loop // because the parent of the last layer is "", andlstore.Get("") // will return an error. layerSize, err := c.runtime.store.DiffSize(layer.Parent, layer.ID) return size + layerSize, err } // rwSize Gets the size of the mutable top layer of the container. func (c *Container) rwSize() (int64, error) { container, err := c.runtime.store.Container(c.ID()) if err != nil { return 0, err } // Get the size of the top layer by calculating the size of the diff // between the layer and its parent. The top layer of a container is // the only RW layer, all others are immutable layer, err := c.runtime.store.Layer(container.LayerID) if err != nil { return 0, err } return c.runtime.store.DiffSize(layer.Parent, layer.ID) } // The path to the container's root filesystem - where the OCI spec will be // placed, amongst other things func (c *Container) bundlePath() string { return c.config.StaticDir } // The path to the container's logs file func (c *Container) logPath() string { return filepath.Join(c.config.StaticDir, "ctr.log") } // Retrieves the path of the container's attach socket func (c *Container) attachSocketPath() string { return filepath.Join(c.runtime.ociRuntime.socketsDir, c.ID(), "attach") } // Sync this container with on-disk state and runc status // Should only be called with container lock held // This function should suffice to ensure a container's state is accurate and // it is valid for use. func (c *Container) syncContainer() error { if err := c.runtime.state.UpdateContainer(c); err != nil { return err } // If runc knows about the container, update its status in runc // And then save back to disk if (c.state.State != ContainerStateUnknown) && (c.state.State != ContainerStateConfigured) { oldState := c.state.State // TODO: optionally replace this with a stat for the exit file if err := c.runtime.ociRuntime.updateContainerStatus(c); err != nil { return err } // Only save back to DB if state changed if c.state.State != oldState { if err := c.save(); err != nil { return err } } } if !c.valid { return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID()) } return nil } // Make a new container func newContainer(rspec *spec.Spec, lockDir string) (*Container, error) { if rspec == nil { return nil, errors.Wrapf(ErrInvalidArg, "must provide a valid runtime spec to create container") } ctr := new(Container) ctr.config = new(ContainerConfig) ctr.state = new(containerState) ctr.config.ID = stringid.GenerateNonCryptoID() ctr.config.Name = namesgenerator.GetRandomName(0) ctr.config.Spec = new(spec.Spec) deepcopier.Copy(rspec).To(ctr.config.Spec) ctr.config.CreatedTime = time.Now() ctr.config.ShmSize = DefaultShmSize ctr.config.CgroupParent = CgroupParent // Path our lock file will reside at lockPath := filepath.Join(lockDir, ctr.config.ID) // Grab a lockfile at the given path lock, err := storage.GetLockfile(lockPath) if err != nil { return nil, errors.Wrapf(err, "error creating lockfile for new container") } ctr.lock = lock return ctr, nil } // Create container root filesystem for use func (c *Container) setupStorage() error { if !c.valid { return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID()) } if c.state.State != ContainerStateConfigured { return errors.Wrapf(ErrCtrStateInvalid, "container %s must be in Configured state to have storage set up", c.ID()) } // Need both an image ID and image name, plus a bool telling us whether to use the image configuration if c.config.RootfsImageID == "" || c.config.RootfsImageName == "" { return errors.Wrapf(ErrInvalidArg, "must provide image ID and image name to use an image") } containerInfo, err := c.runtime.storageService.CreateContainerStorage(c.runtime.imageContext, c.config.RootfsImageName, c.config.RootfsImageID, c.config.Name, c.config.ID, c.config.MountLabel) if err != nil { return errors.Wrapf(err, "error creating container storage") } c.config.StaticDir = containerInfo.Dir c.state.RunDir = containerInfo.RunDir artifacts := filepath.Join(c.config.StaticDir, artifactsDir) if err := os.MkdirAll(artifacts, 0755); err != nil { return errors.Wrapf(err, "error creating artifacts directory %q", artifacts) } return nil } // Tear down a container's storage prior to removal func (c *Container) teardownStorage() error { if !c.valid { return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID()) } if c.state.State == ContainerStateRunning || c.state.State == ContainerStatePaused { return errors.Wrapf(ErrCtrStateInvalid, "cannot remove storage for container %s as it is running or paused", c.ID()) } artifacts := filepath.Join(c.config.StaticDir, artifactsDir) if err := os.RemoveAll(artifacts); err != nil { return errors.Wrapf(err, "error removing artifacts %q", artifacts) } if err := c.cleanupStorage(); err != nil { return errors.Wrapf(err, "failed to cleanup container %s storage", c.ID()) } if err := c.runtime.storageService.DeleteContainer(c.ID()); err != nil { return errors.Wrapf(err, "error removing container %s root filesystem", c.ID()) } return nil } // Refresh refreshes the container's state after a restart func (c *Container) refresh() error { c.lock.Lock() defer c.lock.Unlock() if !c.valid { return errors.Wrapf(ErrCtrRemoved, "container %s is not valid - may have been removed", c.ID()) } // We need to get the container's temporary directory from c/storage // It was lost in the reboot and must be recreated dir, err := c.runtime.storageService.GetRunDir(c.ID()) if err != nil { return errors.Wrapf(err, "error retrieving temporary directory for container %s", c.ID()) } c.state.RunDir = dir if err := c.runtime.state.SaveContainer(c); err != nil { return errors.Wrapf(err, "error refreshing state for container %s", c.ID()) } return nil } func (c *Container) export(path string) error { mountPoint := c.state.Mountpoint if !c.state.Mounted { mount, err := c.runtime.store.Mount(c.ID(), c.config.MountLabel) if err != nil { return errors.Wrapf(err, "error mounting container %q", c.ID()) } mountPoint = mount defer func() { if err := c.runtime.store.Unmount(c.ID()); err != nil { logrus.Errorf("error unmounting container %q: %v", c.ID(), err) } }() } input, err := archive.Tar(mountPoint, archive.Uncompressed) if err != nil { return errors.Wrapf(err, "error reading container directory %q", c.ID()) } outFile, err := os.Create(path) if err != nil { return errors.Wrapf(err, "error creating file %q", path) } defer outFile.Close() _, err = io.Copy(outFile, input) return err } // Get path of artifact with a given name for this container func (c *Container) getArtifactPath(name string) string { return filepath.Join(c.config.StaticDir, artifactsDir, name) } // Used with Wait() to determine if a container has exited func (c *Container) isStopped() (bool, error) { if !c.locked { c.lock.Lock() defer c.lock.Unlock() } err := c.syncContainer() if err != nil { return true, err } return c.state.State == ContainerStateStopped, nil } // save container state to the database func (c *Container) save() error { if err := c.runtime.state.SaveContainer(c); err != nil { return errors.Wrapf(err, "error saving container %s state", c.ID()) } return nil } // mountStorage sets up the container's root filesystem // It mounts the image and any other requested mounts // TODO: Add ability to override mount label so we can use this for Mount() too // TODO: Can we use this for export? Copying SHM into the export might not be // good func (c *Container) mountStorage() (err error) { // Container already mounted, nothing to do if c.state.Mounted { return nil } // TODO: generalize this mount code so it will mount every mount in ctr.config.Mounts mounted, err := mount.Mounted(c.config.ShmDir) if err != nil { return errors.Wrapf(err, "unable to determine if %q is mounted", c.config.ShmDir) } if !mounted { shmOptions := fmt.Sprintf("mode=1777,size=%d", c.config.ShmSize) if err := unix.Mount("shm", c.config.ShmDir, "tmpfs", unix.MS_NOEXEC|unix.MS_NOSUID|unix.MS_NODEV, label.FormatMountLabel(shmOptions, c.config.MountLabel)); err != nil { return errors.Wrapf(err, "failed to mount shm tmpfs %q", c.config.ShmDir) } } mountPoint, err := c.runtime.storageService.MountContainerImage(c.ID()) if err != nil { return errors.Wrapf(err, "error mounting storage for container %s", c.ID()) } c.state.Mounted = true c.state.Mountpoint = mountPoint logrus.Debugf("Created root filesystem for container %s at %s", c.ID(), c.state.Mountpoint) defer func() { if err != nil { if err2 := c.cleanupStorage(); err2 != nil { logrus.Errorf("Error unmounting storage for container %s: %v", c.ID(), err) } } }() return c.save() } // cleanupStorage unmounts and cleans up the container's root filesystem func (c *Container) cleanupStorage() error { if !c.state.Mounted { // Already unmounted, do nothing return nil } for _, mount := range c.config.Mounts { if err := unix.Unmount(mount, unix.MNT_DETACH); err != nil { if err != syscall.EINVAL { logrus.Warnf("container %s failed to unmount %s : %v", c.ID(), mount, err) } } } // Also unmount storage if err := c.runtime.storageService.UnmountContainerImage(c.ID()); err != nil { return errors.Wrapf(err, "error unmounting container %s root filesystem", c.ID()) } c.state.Mountpoint = "" c.state.Mounted = false return c.save() } // WriteStringToRundir copies the provided file to the runtimedir func (c *Container) WriteStringToRundir(destFile, output string) (string, error) { destFileName := filepath.Join(c.state.RunDir, destFile) f, err := os.Create(destFileName) if err != nil { return "", errors.Wrapf(err, "unable to create %s", destFileName) } defer f.Close() _, err = f.WriteString(output) if err != nil { return "", errors.Wrapf(err, "unable to write %s", destFileName) } // Relabel runDirResolv for the container if err := label.Relabel(destFileName, c.config.MountLabel, false); err != nil { return "", err } return destFileName, nil } type resolv struct { nameServers []string searchDomains []string options []string } // generateResolvConf generates a containers resolv.conf func (c *Container) generateResolvConf() (string, error) { // Copy /etc/resolv.conf to the container's rundir resolvPath := "/etc/resolv.conf" // Check if the host system is using system resolve and if so // copy its resolv.conf if _, err := os.Stat("/run/systemd/resolve/resolv.conf"); err == nil { resolvPath = "/run/systemd/resolve/resolv.conf" } orig, err := ioutil.ReadFile(resolvPath) if err != nil { return "", errors.Wrapf(err, "unable to read %s", resolvPath) } if len(c.config.DNSServer) == 0 && len(c.config.DNSSearch) == 0 && len(c.config.DNSOption) == 0 { return c.WriteStringToRundir("resolv.conf", fmt.Sprintf("%s", orig)) } // Read and organize the hosts /etc/resolv.conf resolv := createResolv(string(orig[:])) // Populate the resolv struct with user's dns search domains if len(c.config.DNSSearch) > 0 { resolv.searchDomains = nil // The . character means the user doesnt want any search domains in the container if !StringInSlice(".", c.config.DNSSearch) { resolv.searchDomains = append(resolv.searchDomains, c.Config().DNSSearch...) } } // Populate the resolv struct with user's dns servers if len(c.config.DNSServer) > 0 { resolv.nameServers = nil for _, i := range c.config.DNSServer { resolv.nameServers = append(resolv.nameServers, i.String()) } } // Populate the resolve struct with the users dns options if len(c.config.DNSOption) > 0 { resolv.options = nil resolv.options = append(resolv.options, c.Config().DNSOption...) } return c.WriteStringToRundir("resolv.conf", resolv.ToString()) } // createResolv creates a resolv struct from an input string func createResolv(input string) resolv { var resolv resolv for _, line := range strings.Split(input, "\n") { if strings.HasPrefix(line, "search") { fields := strings.Fields(line) if len(fields) < 2 { logrus.Debugf("invalid resolv.conf line %s", line) continue } resolv.searchDomains = append(resolv.searchDomains, fields[1:]...) } else if strings.HasPrefix(line, "nameserver") { fields := strings.Fields(line) if len(fields) < 2 { logrus.Debugf("invalid resolv.conf line %s", line) continue } resolv.nameServers = append(resolv.nameServers, fields[1]) } else if strings.HasPrefix(line, "options") { fields := strings.Fields(line) if len(fields) < 2 { logrus.Debugf("invalid resolv.conf line %s", line) continue } resolv.options = append(resolv.options, fields[1:]...) } } return resolv } //ToString returns a resolv struct in the form of a resolv.conf func (r resolv) ToString() string { var result string // Populate the output string with search domains result += fmt.Sprintf("search %s\n", strings.Join(r.searchDomains, " ")) // Populate the output string with name servers for _, i := range r.nameServers { result += fmt.Sprintf("nameserver %s\n", i) } // Populate the output string with dns options for _, i := range r.options { result += fmt.Sprintf("options %s\n", i) } return result } // generateHosts creates a containers hosts file func (c *Container) generateHosts() (string, error) { orig, err := ioutil.ReadFile("/etc/hosts") if err != nil { return "", errors.Wrapf(err, "unable to read /etc/hosts") } hosts := string(orig) if len(c.config.HostAdd) > 0 { for _, host := range c.config.HostAdd { // the host format has already been verified at this point fields := strings.Split(host, ":") hosts += fmt.Sprintf("%s %s\n", fields[0], fields[1]) } } return c.WriteStringToRundir("hosts", hosts) }