Image Resolution Stage 1

This is the stage 1 effort for an image library that can be eventually used by buildah and
podman alike.  In eventuality, the main goal of the library (package) is to:

* provide a consistent approach to resolving image names in various forms (from users).
* based on the result of the above, provide image methods that in a singular spot but separate from the runtime.
* reduce the cruft and bloat in the current podman runtime.

The goal of stage 1 is to demonstrate fast, accurate image resolution for both local and remote images resulting in
an image object as part of the return.

Signed-off-by: baude <bbaude@redhat.com>

Closes: #463
Approved by: baude

1 files changed, 184 insertions, 0 deletions

diff --git a/libpod/image/image_test.go b/libpod/image/image_test.go
new file mode 100644
index 000000000..4b5b782b1
--- /dev/null
+++ b/libpod/image/image_test.go
@@ -0,0 +1,184 @@
+package image
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"testing"
+
+	"github.com/containers/storage"
+	"github.com/containers/storage/pkg/reexec"
+	"github.com/pkg/errors"
+	"github.com/projectatomic/libpod/libpod"
+	"github.com/stretchr/testify/assert"
+)
+
+var (
+	bbNames      = []string{"docker.io/library/busybox:latest", "docker.io/library/busybox", "docker.io/busybox:latest", "docker.io/busybox", "busybox:latest", "busybox"}
+	bbGlibcNames = []string{"docker.io/library/busybox:glibc", "docker.io/busybox:glibc", "busybox:glibc"}
+	fedoraNames  = []string{"registry.fedoraproject.org/fedora-minimal:latest", "registry.fedoraproject.org/fedora-minimal", "fedora-minimal:latest", "fedora-minimal"}
+)
+
+// setup a runtime for the tests in an alternative location on the filesystem
+func setupRuntime(workdir string) (*libpod.Runtime, error) {
+	if reexec.Init() {
+		return nil, errors.Errorf("dude")
+	}
+	sc := libpod.WithStorageConfig(storage.StoreOptions{
+		GraphRoot: workdir,
+		RunRoot:   workdir,
+	})
+	sd := libpod.WithStaticDir(path.Join(workdir, "libpod_tmp"))
+	td := libpod.WithTmpDir(path.Join(workdir, "tmpdir"))
+
+	options := []libpod.RuntimeOption{sc, sd, td}
+	return libpod.NewRuntime(options...)
+}
+
+// getImage is only used to build a test matrix for testing local images
+func getImage(r *libpod.Runtime, fqImageName string) (*storage.Image, error) {
+	img, err := NewFromLocal(fqImageName, r)
+	if err != nil {
+		return nil, err
+	}
+	return img.image, nil
+}
+
+func tagImage(r *libpod.Runtime, fqImageName, tagName string) error {
+	img, err := NewFromLocal(fqImageName, r)
+	if err != nil {
+		return err
+	}
+	r.TagImage(img.image, tagName)
+	return nil
+}
+
+type localImageTest struct {
+	fqname, taggedName string
+	img                *storage.Image
+	names              []string
+}
+
+// make a temporary directory for the runtime
+func mkWorkDir() (string, error) {
+	return ioutil.TempDir("", "podman-test")
+}
+
+// shutdown the runtime and clean behind it
+func cleanup(r *libpod.Runtime, workdir string) {
+	r.Shutdown(true)
+	err := os.RemoveAll(workdir)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func makeLocalMatrix(r *libpod.Runtime) ([]localImageTest, error) {
+	var l []localImageTest
+	// busybox
+	busybox := localImageTest{
+		fqname:     "docker.io/library/busybox:latest",
+		taggedName: "bb:latest",
+	}
+	b, err := getImage(r, busybox.fqname)
+	if err != nil {
+		return nil, err
+	}
+	busybox.img = b
+	busybox.names = bbNames
+	busybox.names = append(busybox.names, []string{"bb:latest", "bb", b.ID, b.ID[0:7], fmt.Sprintf("busybox@%s", b.Digest.String())}...)
+
+	//fedora
+	fedora := localImageTest{
+		fqname:     "registry.fedoraproject.org/fedora-minimal:latest",
+		taggedName: "f27:latest",
+	}
+	f, err := getImage(r, fedora.fqname)
+	if err != nil {
+		return nil, err
+	}
+	fedora.img = f
+	fedora.names = fedoraNames
+
+	// busybox-glibc
+	busyboxGlibc := localImageTest{
+		fqname:     "docker.io/library/busybox:glibc",
+		taggedName: "bb:glibc",
+	}
+	bg, err := getImage(r, busyboxGlibc.fqname)
+	if err != nil {
+		return nil, err
+	}
+	busyboxGlibc.img = bg
+	busyboxGlibc.names = bbGlibcNames
+
+	l = append(l, busybox, fedora)
+	return l, nil
+
+}
+
+// TestImage_NewFromLocal tests finding the image locally by various names,
+// tags, and aliases
+func TestImage_NewFromLocal(t *testing.T) {
+	workdir, err := mkWorkDir()
+	assert.NoError(t, err)
+	runtime, err := setupRuntime(workdir)
+	assert.NoError(t, err)
+
+	// Need images to be present for this test
+	_, err = runtime.PullImage("docker.io/library/busybox:latest", libpod.CopyOptions{})
+	assert.NoError(t, err)
+	_, err = runtime.PullImage("docker.io/library/busybox:glibc", libpod.CopyOptions{})
+	assert.NoError(t, err)
+	_, err = runtime.PullImage("registry.fedoraproject.org/fedora-minimal:latest", libpod.CopyOptions{})
+	assert.NoError(t, err)
+
+	tm, err := makeLocalMatrix(runtime)
+	assert.NoError(t, err)
+	for _, image := range tm {
+		// tag our images
+		err = tagImage(runtime, image.fqname, image.taggedName)
+		assert.NoError(t, err)
+		for _, name := range image.names {
+			newImage, err := NewFromLocal(name, runtime)
+			assert.NoError(t, err)
+			assert.Equal(t, newImage.ID(), image.img.ID)
+		}
+	}
+
+	// Shutdown the runtime and remove the temporary storage
+	cleanup(runtime, workdir)
+}
+
+// TestImage_New tests pulling the image by various names, tags, and from
+// different registries
+func TestImage_New(t *testing.T) {
+	var names []string
+	workdir, err := mkWorkDir()
+	assert.NoError(t, err)
+	runtime, err := setupRuntime(workdir)
+	assert.NoError(t, err)
+
+	// Build the list of pull names
+	names = append(names, bbNames...)
+	names = append(names, fedoraNames...)
+
+	// Iterate over the names and delete the image
+	// after the pull
+	for _, img := range names {
+		_, err := runtime.GetImage(img)
+		if err == nil {
+			os.Exit(1)
+		}
+		newImage, err := New(img, runtime)
+		assert.NoError(t, err)
+		assert.NotEqual(t, newImage.ID(), "")
+		err = newImage.Remove(false)
+		assert.NoError(t, err)
+	}
+
+	// Shutdown the runtime and remove the temporary storage
+	cleanup(runtime, workdir)
+}