Use buildah commit for podman commit

Resolves: #586 and #520
Signed-off-by: baude <bbaude@redhat.com>

Closes: #592
Approved by: mheon

1 files changed, 147 insertions, 0 deletions

diff --git a/libpod/buildah/commit.go b/libpod/buildah/commit.go
new file mode 100644
index 000000000..b862031d2
--- /dev/null
+++ b/libpod/buildah/commit.go
@@ -0,0 +1,147 @@
+package buildah
+
+import (
+	"fmt"
+	"io"
+	"time"
+
+	cp "github.com/containers/image/copy"
+	"github.com/containers/image/signature"
+	is "github.com/containers/image/storage"
+	"github.com/containers/image/transports"
+	"github.com/containers/image/types"
+	"github.com/containers/storage"
+	"github.com/containers/storage/pkg/archive"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+// CommitOptions can be used to alter how an image is committed.
+type CommitOptions struct {
+	// PreferredManifestType is the preferred type of image manifest.  The
+	// image configuration format will be of a compatible type.
+	PreferredManifestType string
+	// Compression specifies the type of compression which is applied to
+	// layer blobs.  The default is to not use compression, but
+	// archive.Gzip is recommended.
+	Compression archive.Compression
+	// SignaturePolicyPath specifies an override location for the signature
+	// policy which should be used for verifying the new image as it is
+	// being written.  Except in specific circumstances, no value should be
+	// specified, indicating that the shared, system-wide default policy
+	// should be used.
+	SignaturePolicyPath string
+	// AdditionalTags is a list of additional names to add to the image, if
+	// the transport to which we're writing the image gives us a way to add
+	// them.
+	AdditionalTags []string
+	// ReportWriter is an io.Writer which will be used to log the writing
+	// of the new image.
+	ReportWriter io.Writer
+	// HistoryTimestamp is the timestamp used when creating new items in the
+	// image's history.  If unset, the current time will be used.
+	HistoryTimestamp *time.Time
+	// github.com/containers/image/types SystemContext to hold credentials
+	// and other authentication/authorization information.
+	SystemContext *types.SystemContext
+}
+
+// PushOptions can be used to alter how an image is copied somewhere.
+type PushOptions struct {
+	// Compression specifies the type of compression which is applied to
+	// layer blobs.  The default is to not use compression, but
+	// archive.Gzip is recommended.
+	Compression archive.Compression
+	// SignaturePolicyPath specifies an override location for the signature
+	// policy which should be used for verifying the new image as it is
+	// being written.  Except in specific circumstances, no value should be
+	// specified, indicating that the shared, system-wide default policy
+	// should be used.
+	SignaturePolicyPath string
+	// ReportWriter is an io.Writer which will be used to log the writing
+	// of the new image.
+	ReportWriter io.Writer
+	// Store is the local storage store which holds the source image.
+	Store storage.Store
+	// github.com/containers/image/types SystemContext to hold credentials
+	// and other authentication/authorization information.
+	SystemContext *types.SystemContext
+	// ManifestType is the format to use when saving the imge using the 'dir' transport
+	// possible options are oci, v2s1, and v2s2
+	ManifestType string
+}
+
+// Commit writes the contents of the container, along with its updated
+// configuration, to a new image in the specified location, and if we know how,
+// add any additional tags that were specified.
+func (b *Builder) Commit(dest types.ImageReference, options CommitOptions) error {
+	policy, err := signature.DefaultPolicy(getSystemContext(options.SystemContext, options.SignaturePolicyPath))
+	if err != nil {
+		return errors.Wrapf(err, "error obtaining default signature policy")
+	}
+	policyContext, err := signature.NewPolicyContext(policy)
+	if err != nil {
+		return errors.Wrapf(err, "error creating new signature policy context")
+	}
+	defer func() {
+		if err2 := policyContext.Destroy(); err2 != nil {
+			logrus.Debugf("error destroying signature policy context: %v", err2)
+		}
+	}()
+	// Check if we're keeping everything in local storage.  If so, we can take certain shortcuts.
+	_, destIsStorage := dest.Transport().(is.StoreTransport)
+	exporting := !destIsStorage
+	src, err := b.makeImageRef(options.PreferredManifestType, exporting, options.Compression, options.HistoryTimestamp)
+	if err != nil {
+		return errors.Wrapf(err, "error computing layer digests and building metadata")
+	}
+	// "Copy" our image to where it needs to be.
+	err = cp.Image(policyContext, dest, src, getCopyOptions(options.ReportWriter, nil, options.SystemContext, ""))
+	if err != nil {
+		return errors.Wrapf(err, "error copying layers and metadata")
+	}
+	if len(options.AdditionalTags) > 0 {
+		switch dest.Transport().Name() {
+		case is.Transport.Name():
+			img, err := is.Transport.GetStoreImage(b.store, dest)
+			if err != nil {
+				return errors.Wrapf(err, "error locating just-written image %q", transports.ImageName(dest))
+			}
+			err = AddImageNames(b.store, img, options.AdditionalTags)
+			if err != nil {
+				return errors.Wrapf(err, "error setting image names to %v", append(img.Names, options.AdditionalTags...))
+			}
+			logrus.Debugf("assigned names %v to image %q", img.Names, img.ID)
+		default:
+			logrus.Warnf("don't know how to add tags to images stored in %q transport", dest.Transport().Name())
+		}
+	}
+	return nil
+}
+
+// Push copies the contents of the image to a new location.
+func Push(image string, dest types.ImageReference, options PushOptions) error {
+	systemContext := getSystemContext(options.SystemContext, options.SignaturePolicyPath)
+	policy, err := signature.DefaultPolicy(systemContext)
+	if err != nil {
+		return errors.Wrapf(err, "error obtaining default signature policy")
+	}
+	policyContext, err := signature.NewPolicyContext(policy)
+	if err != nil {
+		return errors.Wrapf(err, "error creating new signature policy context")
+	}
+	// Look up the image.
+	src, err := is.Transport.ParseStoreReference(options.Store, image)
+	if err != nil {
+		return errors.Wrapf(err, "error parsing reference to image %q", image)
+	}
+	// Copy everything.
+	err = cp.Image(policyContext, dest, src, getCopyOptions(options.ReportWriter, nil, options.SystemContext, options.ManifestType))
+	if err != nil {
+		return errors.Wrapf(err, "error copying layers and metadata")
+	}
+	if options.ReportWriter != nil {
+		fmt.Fprintf(options.ReportWriter, "\n")
+	}
+	return nil
+}