Enhanced explanation of volume handling with podman

Add more explanatory documentation why is parsing of
volumes needed during creation of container to stay
consistent with the documentation inside docker worker.

Change-Id: Id7c90a6ec04f4a21a75f2edb39f80a64199b5f86
Signed-off-by: Ivan Halomi <ivan.halomi@tietoevry.com>

1 files changed, 13 insertions, 6 deletions

diff --git a/ansible/module_utils/kolla_podman_worker.py b/ansible/module_utils/kolla_podman_worker.py
index 1f9b57067..b34bd3d68 100644
--- a/ansible/module_utils/kolla_podman_worker.py
+++ b/ansible/module_utils/kolla_podman_worker.py
@@ -49,7 +49,7 @@ CONTAINER_PARAMS = [
     'ipc_mode',         # string only option is host
 
     'labels',           # dict
-    'netns',            # dict # TODO(i.halomi) - not sure how it works
+    'netns',            # dict
     'network_options',  # string - none,bridge,host,container:id,
                         # missing in docker but needs to be host
     'pid_mode',         # "string"  host, private or ''
@@ -59,7 +59,7 @@ CONTAINER_PARAMS = [
     'restart_tries',    # int doesn't matter done by systemd
     'stop_timeout',     # int
     'tty',              # bool
-    # VOLUMES NOT WORKING HAS TO BE DONE WITH MOUNTS
+    # volumes need to be parsed, see parse_volumes() for more info
     'volumes',          # array of dict
     'volumes_from',     # array of strings
 ]
@@ -145,6 +145,10 @@ class PodmanWorker(ContainerWorker):
 
         return args
 
+    # NOTE(i.halomi): Podman encounters issues parsing and setting
+    # permissions for a mix of volumes and binds when sent together.
+    # Therefore, we must parse them and set the permissions ourselves
+    # and send them to API separately.
     def parse_volumes(self, volumes, mounts, filtered_volumes):
         # we can ignore empty strings
         volumes = [item for item in volumes if item.strip()]
@@ -390,10 +394,10 @@ class PodmanWorker(ContainerWorker):
     def compare_dimensions(self, container_info):
         new_dimensions = self.params.get('dimensions')
 
-        # NOTE(mgoddard): The names used by Docker are inconsistent between
-        # configuration of a container's resources and the resources in
-        # container_info['HostConfig']. This provides a mapping between the
-        # two.
+        # NOTE(mgoddard): The names used by Docker/Podman are inconsistent
+        # between configuration of a container's resources and
+        # the resources in container_info['HostConfig'].
+        # This provides a mapping between the two.
         dimension_map = {
             'mem_limit': 'Memory', 'mem_reservation': 'MemoryReservation',
             'memswap_limit': 'MemorySwap', 'cpu_period': 'CpuPeriod',
@@ -432,6 +436,9 @@ class PodmanWorker(ContainerWorker):
 
             rc, raw_output = container.exec_run(COMPARE_CONFIG_CMD,
                                                 user='root')
+        # APIError means either container doesn't exist or exec command
+        # failed, which means that container is in bad state and we can
+        # expect that config is stale so we return True and recreate container
         except APIError as e:
             if e.is_client_error():
                 return True