Check the image is outdated and pop warning to pull the latest

aiidalab_launch/__main__.py

@@ -347,14 +347,17 @@ async def _async_start(
         with spinner(msg):
             instance.pull()
     else:
+        from aiidalab_launch import util
+
         # use local image
         msg = f"Using local image '{profile.image}'."
 
-    if instance.image is None:
-        raise click.ClickException(
-            f"Unable to find image '{profile.image}'. "
-            "Try to use '--pull' to pull the image prior to start."
-        )
+        # check if local image is outdated and pull latest version if so
+        if not util.image_is_latest(instance.client, profile.image):
+            click.secho(
+                "Warning! Local image is outdated, please run with --pull to update.",
+                fg="yellow",
+            )
 
     # Check if the container configuration has changed.
     if instance.container:

aiidalab_launch/util.py

@@ -225,3 +225,26 @@ def get_docker_env(container: docker.models.containers.Container, env_name: str)
     except KeyError:
         pass
     raise KeyError(env_name)
+
+
+def image_is_latest(docker_client, image: str):
+    """Check if the local image has the same digest as the image
+    on remote registry.
+    """
+    try:
+        local_image = docker_client.images.get(image)
+    except docker.errors.ImageNotFound:
+        return False
+
+    try:
+        remote_image = docker_client.images.get_registry_data(image)
+    except docker.errors.APIError:
+        return False
+
+    # There is no need to check creation date of the image, since the once
+    # there is a new image with the same tag, the id will be different.
+    # We can not use image id, see https://windsock.io/explaining-docker-image-ids/
+    local_digest = local_image.attrs.get("RepoDigests")[0].split("@")[-1]
+    remote_digest = remote_image.attrs.get("Descriptor", {}).get("digest")
+
+    return local_digest == remote_digest

tests/conftest.py

@@ -57,6 +57,19 @@ def docker_client():
         pytest.skip("docker not available")
 
 
+@pytest.fixture(scope="function")
+def remove_created_images(docker_client):
+    """Remove all images created by the tests."""
+    images = docker_client.images.list()
+    yield
+    for image in docker_client.images.list():
+        if image not in images:
+            try:
+                image.remove()
+            except docker.errors.APIError:
+                pass
+
+
 @pytest.fixture(autouse=True)
 def _select_default_image(monkeypatch_session, pytestconfig):
     _default_image = pytestconfig.getoption("default_image")

tests/test_cli.py

@@ -208,7 +208,7 @@ def test_remove_running_profile(self):
 @pytest.mark.slow
 @pytest.mark.trylast
 class TestInstanceLifecycle:
-    def test_start_stop_reset(self, instance, docker_client, caplog):
+    def test_start_stop_reset(self, instance, docker_client, caplog, monkeypatch):
         caplog.set_level(logging.DEBUG)
 
         def get_volume(volume_name):
@@ -260,6 +260,20 @@ def assert_status_down():
         assert result.exit_code == 0
         assert_status_up()
 
+        # test the warning message of image not the latest is not raised
+        assert "Warning!" not in result.output.strip()
+
+        # Then by monkeypatching the image_is_latest function, we can test that
+        # the warning message is raised
+        def image_is_latest(docker_client, image_name):
+            return False
+
+        monkeypatch.setattr("aiidalab_launch.util.image_is_latest", image_is_latest)
+        result: Result = runner.invoke(
+            cli.cli, ["start", "--no-browser", "--no-pull", "--wait=300"]
+        )
+        assert "Warning!" in result.output.strip()
+
         # Restart instance.
         # TODO: This test is currently disabled, because it is too flaky.  For
         # a currently unknown reason, the docker client will not be able to

tests/test_util.py

@@ -1,8 +1,9 @@
 from time import time
 
+import pytest
 from packaging.version import parse
 
-from aiidalab_launch.util import get_latest_version
+from aiidalab_launch.util import get_latest_version, image_is_latest
 
 
 def test_get_latest_version(mock_pypi_request):
@@ -13,3 +14,31 @@ def test_get_latest_version_timeout(mock_pypi_request_timeout):
     start = time()
     assert get_latest_version() is None
     assert (time() - start) < 0.5
+
+
+@pytest.mark.usefixtures("enable_docker_pull")
+@pytest.mark.usefixtures("remove_created_images")
+def test_image_is_latest(docker_client):
+    """Test that the latest version is identified correctly."""
+    # download the alpine image for testing
+    image_name = "alpine:latest"
+    docker_client.images.pull(image_name)
+
+    # check that the image is identified as latest
+    assert image_is_latest(docker_client, image_name)
+
+
+@pytest.mark.usefixtures("enable_docker_pull")
+@pytest.mark.usefixtures("remove_created_images")
+def test_image_is_not_latest(docker_client):
+    """Test that the outdate version is identified correctly and will ask for pull the latest."""
+    # download the alpine image for testing
+    old_image_name = "alpine:2.6"
+    latest_image_name = "alpine:latest"
+
+    # pull the old image and retag it as latest to mock the outdated image
+    old_image = docker_client.images.pull(old_image_name)
+    old_image.tag(latest_image_name)
+
+    # check that the image is identified as latest
+    assert not image_is_latest(docker_client, latest_image_name)