Don't error when image pull fails and image exists:

HookOS recently got the capability to embed container
images. With this capability, pulling an image is not
desired. This is expecially true if the image name is
not resolvable or there is no network connection to
the registry. An image name 127.0.0.1/embedded/myimage,
for example.

Currently, tink worker will always try to pull an image
and will fail if the image pull fails. To allow for
embedded images to function properly, when an image
pull fails we check if the image already exists in the
local Docker cache. If it does we don't fail the method
call.

Signed-off-by: Jacob Weinstock <[email protected]>

cmd/tink-worker/worker/registry.go

@@ -31,6 +31,7 @@ type ImagePullStatus struct {
 }
 
 // PullImage outputs to stdout the contents of the requested image (relative to the registry).
+// If a pull fails but the image already exists then we will return a nil error.
 func (m *containerManager) PullImage(ctx context.Context, img string) error {
 	l := m.getLogger(ctx)
 	authConfig := registry.AuthConfig{
@@ -46,6 +47,9 @@ func (m *containerManager) PullImage(ctx context.Context, img string) error {
 
 	out, err := m.cli.ImagePull(ctx, path.Join(m.registryDetails.Registry, img), image.PullOptions{RegistryAuth: authStr})
 	if err != nil {
+		if _, _, err := m.cli.ImageInspectWithRaw(ctx, path.Join(m.registryDetails.Registry, img)); err == nil {
+			return nil
+		}
 		return errors.Wrap(err, "DOCKER PULL")
 	}
 	defer func() {