Podman load can pull in compressed files

Podman load can now load in docker-archive files that are compressed.

Signed-off-by: umohnani8 <umohnani@redhat.com>

Closes: #468
Approved by: baude

libpod/runtime_img.go

@@ -606,7 +606,10 @@ func (r *Runtime) getPullListFromRef(srcRef types.ImageReference, imgName string
 
 	// supports pulling from docker-archive, oci, and registries
 	if srcRef.Transport().Name() == DockerArchive {
-		tarSource := tarfile.NewSource(archFile)
+		tarSource, err := tarfile.NewSourceFromFile(archFile)
+		if err != nil {
+			return nil, err
+		}
 		manifest, err := tarSource.LoadTarManifest()
 		if err != nil {
 			return nil, errors.Errorf("error retrieving manifest.json: %v", err)

test/e2e/load_test.go

@@ -44,6 +44,26 @@ var _ = Describe("Podman load", func() {
 		Expect(result.ExitCode()).To(Equal(0))
 	})
 
+	It("podman load compressed tar file", func() {
+		outfile := filepath.Join(podmanTest.TempDir, "alpine.tar")
+
+		save := podmanTest.Podman([]string{"save", "-o", outfile, ALPINE})
+		save.WaitWithDefaultTimeout()
+		Expect(save.ExitCode()).To(Equal(0))
+
+		compress := podmanTest.SystemExec("gzip", []string{outfile})
+		compress.WaitWithDefaultTimeout()
+		outfile = outfile + ".gz"
+
+		rmi := podmanTest.Podman([]string{"rmi", ALPINE})
+		rmi.WaitWithDefaultTimeout()
+		Expect(rmi.ExitCode()).To(Equal(0))
+
+		result := podmanTest.Podman([]string{"load", "-i", outfile})
+		result.WaitWithDefaultTimeout()
+		Expect(result.ExitCode()).To(Equal(0))
+	})
+
 	It("podman load oci-archive image", func() {
 		outfile := filepath.Join(podmanTest.TempDir, "alpine.tar")