Check the image is outdated and pop warning to pull the latest

Author: unkcpz

aiidalab_launch/__main__.py

@@ -21,7 +21,13 @@
 from .core import LOGGER
 from .instance import AiidaLabInstance
 from .profile import DEFAULT_IMAGE, DEFAULT_PORT, Profile
-from .util import confirm_with_value, get_latest_version, spinner, webbrowser_available
+from .util import (
+    confirm_with_value,
+    get_latest_version,
+    image_is_latest,
+    spinner,
+    webbrowser_available,
+)
 from .version import __version__
 
 MSG_MOUNT_POINT_CONFLICT = """Warning: There is at least one other running
@@ -350,6 +356,13 @@ async def _async_start(
         # use local image
         msg = f"Using local image '{profile.image}'."
 
+        # check if local image is outdated and pull latest version if so
+        if not image_is_latest(instance.client, profile.image):
+            click.secho(
+                "Warning! Local image is outdated, please run with --pull to update.",
+                fg="yellow",
+            )
+
     if instance.image is None:
         raise click.ClickException(
             f"Unable to find image '{profile.image}'. "

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/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 +14,14 @@ 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")
+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)