Bugfix: gracefully handle incorrectly set min_disk property (#689)

Signed-off-by: Matthias Büchse <[email protected]>

Tests/iaas/entropy/entropy-check.py

@@ -321,16 +321,17 @@ def create_vm(env, all_flavors, image, server_name=SERVER_NAME):
     # try to pick a frugal flavor
     flavor = min(flavors, key=lambda flv: flv.vcpus + flv.ram / 3.0 + flv.disk / 10.0)
     userdata = next((value for key, value in SERVER_USERDATA.items() if image.name.lower().startswith(key)), None)
+    volume_size = max(image.min_disk, 8)  # sometimes, the min_disk property is not set correctly
     # create a server with the image and the flavor as well as
     # the previously created keys and security group
     logger.debug(
         f"Creating instance of image '{image.name}' using flavor '{flavor.name}' and "
-        f"{image.min_disk} GiB ephemeral boot volume"
+        f"{volume_size} GiB ephemeral boot volume"
     )
     server = env.conn.create_server(
         server_name, image=image, flavor=flavor, key_name=env.keypair.name, network=env.network,
         security_groups=[env.sec_group.id], userdata=userdata, wait=True, timeout=500, auto_ip=True,
-        boot_from_volume=True, terminate_volume=True, volume_size=image.min_disk,
+        boot_from_volume=True, terminate_volume=True, volume_size=volume_size,
     )
     logger.debug(f"Server '{server_name}' ('{server.id}') has been created")
     return server