Workaround import openstack bug (#291)

* workaround import openstack bug

* use error log level

* lint

* catch OSError instead of FileNotFoundError

src/openstack_cloud/__init__.py

@@ -4,6 +4,8 @@
 """Module for managing Openstack cloud."""
 
 import logging
+import os
+import shutil
 from pathlib import Path
 from typing import TypedDict, cast
 
@@ -17,6 +19,52 @@
 CLOUDS_YAML_PATH = Path(Path.home() / ".config/openstack/clouds.yaml")
 
 
+# Make sure we can import openstack, if not remove the old openstacksdk library and retry.
+# This is a workaround for https://bugs.launchpad.net/juju/+bug/2058335
+def _remove_old_openstacksdk_lib() -> None:
+    """Remove the old openstacksdk library if it exists."""
+    try:
+        unit_name = os.environ["JUJU_UNIT_NAME"].replace("/", "-")
+        venv_dir = Path(f"/var/lib/juju/agents/unit-{unit_name}/charm/venv/")
+        openstacksdk_dirs = list(venv_dir.glob("openstacksdk-*.dist-info"))
+        # use error log level as logging may not be fully initialized yet
+        logger.error("Found following openstack dirs: %s", openstacksdk_dirs)
+        if len(openstacksdk_dirs) > 1:
+            openstacksdk_dirs.sort()
+            for openstacksdk_dir in openstacksdk_dirs[:-1]:
+                logger.error("Removing old openstacksdk library: %s", openstacksdk_dir)
+                shutil.rmtree(openstacksdk_dir)
+        else:
+            logger.error(
+                "No old openstacksdk library to remove. "
+                "Please reach out to the charm dev team for further advice."
+            )
+    except OSError:
+        logger.exception(
+            "Failed to remove old openstacksdk library. "
+            "Please reach out to the charm dev team for further advice."
+        )
+
+
+try:
+    import openstack
+except AttributeError:
+    logger.error(
+        "Failed to import openstack. "
+        "Assuming juju bug https://bugs.launchpad.net/juju/+bug/2058335. "
+        "Removing old openstacksdk library and retrying."
+    )
+    _remove_old_openstacksdk_lib()
+    try:
+        # The import is there to make sure the charm fails if the openstack import is not working.
+        import openstack  # noqa: F401
+    except AttributeError:
+        logger.exception(
+            "Failed to import openstack. Please reach out to the charm team for further advice."
+        )
+        raise
+
+
 class CloudConfig(TypedDict):
     """The parsed clouds.yaml configuration dictionary.