PoC: zfs support

dive/get_image_resolver.go

@@ -2,6 +2,7 @@ package dive
 
 import (
 	"fmt"
+	"github.com/wagoodman/dive/dive/image/zfs"
 	"net/url"
 	"strings"
 
@@ -15,6 +16,7 @@ const (
 	SourceDockerEngine
 	SourcePodmanEngine
 	SourceDockerArchive
+	SourceZFS
 )
 
 type ImageSource int
@@ -22,10 +24,11 @@ type ImageSource int
 var ImageSources = []string{SourceDockerEngine.String(), SourcePodmanEngine.String(), SourceDockerArchive.String()}
 
 func (r ImageSource) String() string {
-	return [...]string{"unknown", "docker", "podman", "docker-archive"}[r]
+	return [...]string{"unknown", "docker", "podman", "docker-archive", "zfs"}[r]
 }
 
 func ParseImageSource(r string) ImageSource {
+
 	switch r {
 	case SourceDockerEngine.String():
 		return SourceDockerEngine
@@ -57,6 +60,8 @@ func DeriveImageSource(image string) (ImageSource, string) {
 		return SourceDockerArchive, imageSource
 	case "docker-tar":
 		return SourceDockerArchive, imageSource
+	case SourceZFS.String():
+		return SourceZFS, imageSource
 	}
 	return SourceUnknown, ""
 }
@@ -69,6 +74,8 @@ func GetImageResolver(r ImageSource) (image.Resolver, error) {
 		return podman.NewResolverFromEngine(), nil
 	case SourceDockerArchive:
 		return docker.NewResolverFromArchive(), nil
+	case SourceZFS:
+		return zfs.NewResolverFromEngine(), nil
 	}
 
 	return nil, fmt.Errorf("unable to determine image resolver")

dive/image/zfs/resolver.go

@@ -0,0 +1,124 @@
+package zfs
+
+import (
+	"errors"
+	"fmt"
+	"github.com/mistifyio/go-zfs"
+	"github.com/sirupsen/logrus"
+	"github.com/wagoodman/dive/dive/filetree"
+	"github.com/wagoodman/dive/dive/image"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+type resolver struct{}
+
+func NewResolverFromEngine() *resolver {
+	return &resolver{}
+}
+
+func (r *resolver) Build(args []string) (*image.Image, error) {
+	return nil, errors.New("can't build ZFS")
+}
+
+func (r *resolver) Fetch(id string) (*image.Image, error) {
+
+	img, err := r.resolveFromZfsDataset(id)
+	if err == nil {
+		return img, err
+	}
+
+	return nil, fmt.Errorf("unable to resolve image '%s': %+v", id, err)
+}
+
+func filterOutDatasetSnapshots(snapshots []*zfs.Dataset, datasetName string) []*zfs.Dataset {
+	var result []*zfs.Dataset
+	for _, snap := range snapshots {
+		if strings.HasPrefix(snap.Name, datasetName+"@") {
+			result = append(result, snap)
+		}
+	}
+	return result
+}
+
+func iterate(path string) ([]string, error) {
+	cmd := exec.Command("find", path, "-type", "f", "-o", "-type", "d")
+	//cmd.Stderr = os.Stderr
+	stdout, _ := cmd.Output()
+	//if err != nil {
+	//	println("Error is")
+	//	println(err.Error())
+	//	panic(err)
+	//}
+	//println("Returning iterate")
+	//println(stdout)
+	//time.Sleep(100000)
+	return strings.Split(string(stdout), "\n"), nil
+}
+
+func (r *resolver) resolveFromZfsDataset(id string) (*image.Image, error) {
+	ds, err := zfs.GetDataset(id)
+	if err != nil {
+		return nil, err
+	}
+
+	snapshots, err := ds.Snapshots()
+	snapshots = filterOutDatasetSnapshots(snapshots, ds.Name)
+	if err != nil {
+		return nil, err
+	}
+
+	var trees []*filetree.FileTree
+	var layers []*image.Layer
+
+	dsMountpoint := ds.Mountpoint
+
+	if dsMountpoint == "" {
+		return nil, errors.New("Failed to find mountpoint for " + ds.Name)
+	}
+
+	for idx, snap := range snapshots {
+		snapName := strings.TrimPrefix(snap.Name, ds.Name+"@")
+		logrus.Info("Processing snapshot " + snapName)
+		snapMountpoint := dsMountpoint + ".zfs/snapshot/" + snapName
+
+		tree := filetree.NewFileTree()
+		files, err := iterate(snapMountpoint)
+		if err != nil {
+			return nil, err
+		}
+		for _, realPath := range files {
+			virtualPath := strings.TrimPrefix(realPath, snapMountpoint)
+			if virtualPath == "" {
+				continue
+			}
+			osStat, err := os.Lstat(realPath)
+			if err != nil {
+				return nil, err
+			}
+			//print("Adding virtualPath: " + virtualPath)
+			println("Adding realPath: " + realPath)
+			_, _, err = tree.AddPath(virtualPath, filetree.NewFileInfo(realPath, virtualPath, osStat))
+			if err != nil {
+				return nil, err
+			}
+		}
+		trees = append(trees, tree)
+		layers = append(layers, &image.Layer{
+			Id:      snapName,
+			Index:   idx,
+			Command: "zfs snapshot command",
+			Size:    uint64(tree.VisibleSize()),
+			Tree:    tree,
+			Names:   make([]string, 0),
+			Digest:  "zfs snapshot digest-" + snapName,
+		})
+
+	}
+	logrus.Info("Returning resolved zfs image obj")
+	return &image.Image{
+		Trees:  trees,
+		Layers: layers,
+	}, nil
+}

go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/google/uuid v1.1.1
 	github.com/logrusorgru/aurora v0.0.0-20190803045625-94edacc10f9b
 	github.com/lunixbochs/vtclean v1.0.0
+	github.com/mistifyio/go-zfs v2.1.1+incompatible
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/phayes/permbits v0.0.0-20190612203442-39d7c581d2ee
 	github.com/sergi/go-diff v1.0.0

go.sum

@@ -112,6 +112,8 @@ github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzp
 github.com/mattn/go-runewidth v0.0.10 h1:CoZ3S2P7pvtP45xOtBw+/mDL2z0RKI576gSkzRRpdGg=
 github.com/mattn/go-runewidth v0.0.10/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/mistifyio/go-zfs v2.1.1+incompatible h1:gAMO1HM9xBRONLHHYnu5iFsOJUiJdNZo6oqSENd4eW8=
+github.com/mistifyio/go-zfs v2.1.1+incompatible/go.mod h1:8AuVvqP/mXw1px98n46wfvcGfQ4ci2FwoAjKYxuo3Z4=
 github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=