package autoupdate import ( "context" "os" "sort" "github.com/containers/image/v5/docker" "github.com/containers/image/v5/docker/reference" "github.com/containers/image/v5/manifest" "github.com/containers/image/v5/transports/alltransports" "github.com/containers/libpod/libpod" "github.com/containers/libpod/libpod/define" "github.com/containers/libpod/libpod/image" "github.com/containers/libpod/pkg/systemd" systemdGen "github.com/containers/libpod/pkg/systemd/generate" "github.com/containers/libpod/pkg/util" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) // Label denotes the container/pod label key to specify auto-update policies in // container labels. const Label = "io.containers.autoupdate" // Policy represents an auto-update policy. type Policy string const ( // PolicyDefault is the default policy denoting no auto updates. PolicyDefault Policy = "disabled" // PolicyNewImage is the policy to update as soon as there's a new image found. PolicyNewImage = "image" ) // Map for easy lookups of supported policies. var supportedPolicies = map[string]Policy{ "": PolicyDefault, "disabled": PolicyDefault, "image": PolicyNewImage, } // LookupPolicy looksup the corresponding Policy for the specified // string. If none is found, an errors is returned including the list of // supported policies. // // Note that an empty string resolved to PolicyDefault. func LookupPolicy(s string) (Policy, error) { policy, exists := supportedPolicies[s] if exists { return policy, nil } // Sort the keys first as maps are non-deterministic. keys := []string{} for k := range supportedPolicies { if k != "" { keys = append(keys, k) } } sort.Strings(keys) return "", errors.Errorf("invalid auto-update policy %q: valid policies are %+q", s, keys) } // ValidateImageReference checks if the specified imageName is a fully-qualified // image reference to the docker transport (without digest). Such a reference // includes a domain, name and tag (e.g., quay.io/podman/stable:latest). The // reference may also be prefixed with "docker://" explicitly indicating that // it's a reference to the docker transport. func ValidateImageReference(imageName string) error { // Make sure the input image is a docker. imageRef, err := alltransports.ParseImageName(imageName) if err == nil && imageRef.Transport().Name() != docker.Transport.Name() { return errors.Errorf("auto updates require the docker image transport but image is of transport %q", imageRef.Transport().Name()) } else if err != nil { repo, err := reference.Parse(imageName) if err != nil { return errors.Wrap(err, "error enforcing fully-qualified docker transport reference for auto updates") } if _, ok := repo.(reference.NamedTagged); !ok { return errors.Errorf("auto updates require fully-qualified image references (no tag): %q", imageName) } if _, ok := repo.(reference.Digested); ok { return errors.Errorf("auto updates require fully-qualified image references without digest: %q", imageName) } } return nil } // AutoUpdate looks up containers with a specified auto-update policy and acts // accordingly. If the policy is set to PolicyNewImage, it checks if the image // on the remote registry is different than the local one. If the image digests // differ, it pulls the remote image and restarts the systemd unit running the // container. // // It returns a slice of successfully restarted systemd units and a slice of // errors encountered during auto update. func AutoUpdate(runtime *libpod.Runtime) ([]string, []error) { // Create a map from `image ID -> []*Container`. containerMap, errs := imageContainersMap(runtime) if len(containerMap) == 0 { return nil, errs } // Create a map from `image ID -> *image.Image` for image lookups. imagesSlice, err := runtime.ImageRuntime().GetImages() if err != nil { return nil, []error{err} } imageMap := make(map[string]*image.Image) for i := range imagesSlice { imageMap[imagesSlice[i].ID()] = imagesSlice[i] } // Connect to DBUS. conn, err := systemd.ConnectToDBUS() if err != nil { logrus.Errorf(err.Error()) return nil, []error{err} } defer conn.Close() // Update images. containersToRestart := []*libpod.Container{} updatedRawImages := make(map[string]bool) for imageID, containers := range containerMap { image, exists := imageMap[imageID] if !exists { errs = append(errs, errors.Errorf("container image ID %q not found in local storage", imageID)) return nil, errs } // Now we have to check if the image of any containers must be updated. // Note that the image ID is NOT enough for this check as a given image // may have multiple tags. for i, ctr := range containers { rawImageName := ctr.RawImageName() if rawImageName == "" { errs = append(errs, errors.Errorf("error auto-updating container %q: raw-image name is empty", ctr.ID())) } needsUpdate, err := newerImageAvailable(runtime, image, rawImageName) if err != nil { errs = append(errs, errors.Wrapf(err, "error auto-updating container %q: image check for %q failed", ctr.ID(), rawImageName)) continue } if !needsUpdate { continue } logrus.Infof("Auto-updating container %q using image %q", ctr.ID(), rawImageName) if _, updated := updatedRawImages[rawImageName]; !updated { _, err = updateImage(runtime, rawImageName) if err != nil { errs = append(errs, errors.Wrapf(err, "error auto-updating container %q: image update for %q failed", ctr.ID(), rawImageName)) continue } updatedRawImages[rawImageName] = true } containersToRestart = append(containersToRestart, containers[i]) } } // Restart containers. updatedUnits := []string{} for _, ctr := range containersToRestart { labels := ctr.Labels() unit, exists := labels[systemdGen.EnvVariable] if !exists { // Shouldn't happen but let's be sure of it. errs = append(errs, errors.Errorf("error auto-updating container %q: no %s label found", ctr.ID(), systemdGen.EnvVariable)) continue } _, err := conn.RestartUnit(unit, "replace", nil) if err != nil { errs = append(errs, errors.Wrapf(err, "error auto-updating container %q: restarting systemd unit %q failed", ctr.ID(), unit)) continue } logrus.Infof("Successfully restarted systemd unit %q", unit) updatedUnits = append(updatedUnits, unit) } return updatedUnits, errs } // imageContainersMap generates a map[image ID] -> [containers using the image] // of all containers with a valid auto-update policy. func imageContainersMap(runtime *libpod.Runtime) (map[string][]*libpod.Container, []error) { allContainers, err := runtime.GetAllContainers() if err != nil { return nil, []error{err} } errors := []error{} imageMap := make(map[string][]*libpod.Container) for i, ctr := range allContainers { state, err := ctr.State() if err != nil { errors = append(errors, err) continue } // Only update running containers. if state != define.ContainerStateRunning { continue } // Only update containers with the specific label/policy set. labels := ctr.Labels() value, exists := labels[Label] if !exists { continue } policy, err := LookupPolicy(value) if err != nil { errors = append(errors, err) continue } // Skip non-image labels (could be explicitly disabled). if policy != PolicyNewImage { continue } // Now we know that `ctr` is configured for auto updates. id, _ := ctr.Image() imageMap[id] = append(imageMap[id], allContainers[i]) } return imageMap, errors } // newerImageAvailable returns true if there corresponding image on the remote // registry is newer. func newerImageAvailable(runtime *libpod.Runtime, img *image.Image, origName string) (bool, error) { remoteRef, err := docker.ParseReference("//" + origName) if err != nil { return false, err } remoteImg, err := remoteRef.NewImage(context.Background(), runtime.SystemContext()) if err != nil { return false, err } rawManifest, _, err := remoteImg.Manifest(context.Background()) if err != nil { return false, err } remoteDigest, err := manifest.Digest(rawManifest) if err != nil { return false, err } return img.Digest().String() != remoteDigest.String(), nil } // updateImage pulls the specified image. func updateImage(runtime *libpod.Runtime, name string) (*image.Image, error) { sys := runtime.SystemContext() registryOpts := image.DockerRegistryOptions{} signaturePolicyPath := "" authFilePath := "" if sys != nil { registryOpts.OSChoice = sys.OSChoice registryOpts.ArchitectureChoice = sys.OSChoice registryOpts.DockerCertPath = sys.DockerCertPath signaturePolicyPath = sys.SignaturePolicyPath authFilePath = sys.AuthFilePath } newImage, err := runtime.ImageRuntime().New(context.Background(), docker.Transport.Name()+"://"+name, signaturePolicyPath, authFilePath, os.Stderr, ®istryOpts, image.SigningOptions{}, nil, util.PullImageAlways, ) if err != nil { return nil, err } return newImage, nil }