package buildah import ( "context" "fmt" "os" "strings" "github.com/containers/image/pkg/sysregistries" is "github.com/containers/image/storage" "github.com/containers/image/transports" "github.com/containers/image/transports/alltransports" "github.com/containers/image/types" "github.com/containers/storage" "github.com/opencontainers/selinux/go-selinux" "github.com/opencontainers/selinux/go-selinux/label" "github.com/openshift/imagebuilder" "github.com/pkg/errors" "github.com/projectatomic/buildah/util" "github.com/sirupsen/logrus" ) const ( // BaseImageFakeName is the "name" of a source image which we interpret // as "no image". BaseImageFakeName = imagebuilder.NoBaseImageSpecifier // DefaultTransport is a prefix that we apply to an image name if we // can't find one in the local Store, in order to generate a source // reference for the image that we can then copy to the local Store. DefaultTransport = "docker://" // minimumTruncatedIDLength is the minimum length of an identifier that // we'll accept as possibly being a truncated image ID. minimumTruncatedIDLength = 3 ) func reserveSELinuxLabels(store storage.Store, id string) error { if selinux.GetEnabled() { containers, err := store.Containers() if err != nil { return err } for _, c := range containers { if id == c.ID { continue } else { b, err := OpenBuilder(store, c.ID) if err != nil { if os.IsNotExist(err) { // Ignore not exist errors since containers probably created by other tool // TODO, we need to read other containers json data to reserve their SELinux labels continue } return err } // Prevent different containers from using same MCS label if err := label.ReserveLabel(b.ProcessLabel); err != nil { return err } } } } return nil } func pullAndFindImage(ctx context.Context, store storage.Store, imageName string, options BuilderOptions, sc *types.SystemContext) (*storage.Image, types.ImageReference, error) { ref, err := pullImage(ctx, store, imageName, options, sc) if err != nil { logrus.Debugf("error pulling image %q: %v", imageName, err) return nil, nil, err } img, err := is.Transport.GetStoreImage(store, ref) if err != nil { logrus.Debugf("error reading pulled image %q: %v", imageName, err) return nil, nil, err } return img, ref, nil } func getImageName(name string, img *storage.Image) string { imageName := name if len(img.Names) > 0 { imageName = img.Names[0] // When the image used by the container is a tagged image // the container name might be set to the original image instead of // the image given in the "form" command line. // This loop is supposed to fix this. for _, n := range img.Names { if strings.Contains(n, name) { imageName = n break } } } return imageName } func imageNamePrefix(imageName string) string { prefix := imageName s := strings.Split(imageName, "/") if len(s) > 0 { prefix = s[len(s)-1] } s = strings.Split(prefix, ":") if len(s) > 0 { prefix = s[0] } s = strings.Split(prefix, "@") if len(s) > 0 { prefix = s[0] } return prefix } func imageManifestAndConfig(ctx context.Context, ref types.ImageReference, systemContext *types.SystemContext) (manifest, config []byte, err error) { if ref != nil { src, err := ref.NewImage(ctx, systemContext) if err != nil { return nil, nil, errors.Wrapf(err, "error instantiating image for %q", transports.ImageName(ref)) } defer src.Close() config, err := src.ConfigBlob(ctx) if err != nil { return nil, nil, errors.Wrapf(err, "error reading image configuration for %q", transports.ImageName(ref)) } manifest, _, err := src.Manifest(ctx) if err != nil { return nil, nil, errors.Wrapf(err, "error reading image manifest for %q", transports.ImageName(ref)) } return manifest, config, nil } return nil, nil, nil } func newContainerIDMappingOptions(idmapOptions *IDMappingOptions) storage.IDMappingOptions { var options storage.IDMappingOptions if idmapOptions != nil { options.HostUIDMapping = idmapOptions.HostUIDMapping options.HostGIDMapping = idmapOptions.HostGIDMapping uidmap, gidmap := convertRuntimeIDMaps(idmapOptions.UIDMap, idmapOptions.GIDMap) if len(uidmap) > 0 && len(gidmap) > 0 { options.UIDMap = uidmap options.GIDMap = gidmap } else { options.HostUIDMapping = true options.HostGIDMapping = true } } return options } func resolveImage(ctx context.Context, systemContext *types.SystemContext, store storage.Store, options BuilderOptions) (types.ImageReference, *storage.Image, error) { var ref types.ImageReference var img *storage.Image for _, image := range util.ResolveName(options.FromImage, options.Registry, systemContext, store) { var err error if len(image) >= minimumTruncatedIDLength { if img, err = store.Image(image); err == nil && img != nil && strings.HasPrefix(img.ID, image) { if ref, err = is.Transport.ParseStoreReference(store, img.ID); err != nil { return nil, nil, errors.Wrapf(err, "error parsing reference to image %q", img.ID) } break } } if options.PullPolicy == PullAlways { pulledImg, pulledReference, err := pullAndFindImage(ctx, store, image, options, systemContext) if err != nil { logrus.Debugf("unable to pull and read image %q: %v", image, err) continue } ref = pulledReference img = pulledImg break } srcRef, err := alltransports.ParseImageName(image) if err != nil { if options.Transport == "" { logrus.Debugf("error parsing image name %q: %v", image, err) continue } transport := options.Transport if transport != DefaultTransport { transport = transport + ":" } srcRef2, err := alltransports.ParseImageName(transport + image) if err != nil { logrus.Debugf("error parsing image name %q: %v", image, err) continue } srcRef = srcRef2 } destImage, err := localImageNameForReference(ctx, store, srcRef, options.FromImage) if err != nil { return nil, nil, errors.Wrapf(err, "error computing local image name for %q", transports.ImageName(srcRef)) } if destImage == "" { return nil, nil, errors.Errorf("error computing local image name for %q", transports.ImageName(srcRef)) } ref, err = is.Transport.ParseStoreReference(store, destImage) if err != nil { return nil, nil, errors.Wrapf(err, "error parsing reference to image %q", destImage) } img, err = is.Transport.GetStoreImage(store, ref) if err != nil { if errors.Cause(err) == storage.ErrImageUnknown && options.PullPolicy != PullIfMissing { logrus.Debugf("no such image %q: %v", transports.ImageName(ref), err) continue } pulledImg, pulledReference, err := pullAndFindImage(ctx, store, image, options, systemContext) if err != nil { logrus.Debugf("unable to pull and read image %q: %v", image, err) continue } ref = pulledReference img = pulledImg } break } return ref, img, nil } func newBuilder(ctx context.Context, store storage.Store, options BuilderOptions) (*Builder, error) { var ref types.ImageReference var img *storage.Image var err error var manifest []byte var config []byte if options.FromImage == BaseImageFakeName { options.FromImage = "" } if options.Transport == "" { options.Transport = DefaultTransport } systemContext := getSystemContext(options.SystemContext, options.SignaturePolicyPath) if options.FromImage != "scratch" { ref, img, err = resolveImage(ctx, systemContext, store, options) if err != nil { return nil, err } if options.FromImage != "" && (ref == nil || img == nil) { // If options.FromImage is set but we ended up // with nil in ref or in img then there was an error that // we should return. return nil, errors.Wrapf(storage.ErrImageUnknown, "image %q not found in %s registries", options.FromImage, sysregistries.RegistriesConfPath(systemContext)) } } image := options.FromImage imageID := "" topLayer := "" if img != nil { image = getImageName(imageNamePrefix(image), img) imageID = img.ID topLayer = img.TopLayer } if manifest, config, err = imageManifestAndConfig(ctx, ref, systemContext); err != nil { return nil, errors.Wrapf(err, "error reading data from image %q", transports.ImageName(ref)) } name := "working-container" if options.Container != "" { name = options.Container } else { var err2 error if image != "" { name = imageNamePrefix(image) + "-" + name } suffix := 1 tmpName := name for errors.Cause(err2) != storage.ErrContainerUnknown { _, err2 = store.Container(tmpName) if err2 == nil { suffix++ tmpName = fmt.Sprintf("%s-%d", name, suffix) } } name = tmpName } coptions := storage.ContainerOptions{} coptions.IDMappingOptions = newContainerIDMappingOptions(options.IDMappingOptions) container, err := store.CreateContainer("", []string{name}, imageID, "", "", &coptions) if err != nil { return nil, errors.Wrapf(err, "error creating container") } defer func() { if err != nil { if err2 := store.DeleteContainer(container.ID); err != nil { logrus.Errorf("error deleting container %q: %v", container.ID, err2) } } }() if err = reserveSELinuxLabels(store, container.ID); err != nil { return nil, err } processLabel, mountLabel, err := label.InitLabels(options.CommonBuildOpts.LabelOpts) if err != nil { return nil, err } uidmap, gidmap := convertStorageIDMaps(container.UIDMap, container.GIDMap) namespaceOptions := DefaultNamespaceOptions() namespaceOptions.AddOrReplace(options.NamespaceOptions...) builder := &Builder{ store: store, Type: containerType, FromImage: image, FromImageID: imageID, Config: config, Manifest: manifest, Container: name, ContainerID: container.ID, ImageAnnotations: map[string]string{}, ImageCreatedBy: "", ProcessLabel: processLabel, MountLabel: mountLabel, DefaultMountsFilePath: options.DefaultMountsFilePath, NamespaceOptions: namespaceOptions, ConfigureNetwork: options.ConfigureNetwork, CNIPluginPath: options.CNIPluginPath, CNIConfigDir: options.CNIConfigDir, IDMappingOptions: IDMappingOptions{ HostUIDMapping: len(uidmap) == 0, HostGIDMapping: len(uidmap) == 0, UIDMap: uidmap, GIDMap: gidmap, }, CommonBuildOpts: options.CommonBuildOpts, TopLayer: topLayer, } if options.Mount { _, err = builder.Mount(mountLabel) if err != nil { return nil, errors.Wrapf(err, "error mounting build container") } } builder.initConfig() err = builder.Save() if err != nil { return nil, errors.Wrapf(err, "error saving builder state") } return builder, nil }