op-mode: T7403: add option for forcefully remove a container image

If you have multiple images (tags) loaded for a container which point to the
exact same hash - you can only forcefully delete them.

  vyos@vyos:~$ delete container image 70dc5806
  Error: unable to delete image "70dc5806" by ID with more than one tag
    ([registry.io/foo/bar:v1.0 registry.io/foo/bar:v1.0.1]):
    please force removal

In additon an image that is still beeing used can not be removed from the
system as this would cause infinite container restarts.

  vyos@vyos:~$ delete container image all force
  Cannot delete image "d205499ae8bb" because it is currently being used by
  container "3b290f90e83d"!

1 files changed, 26 insertions, 4 deletions

diff --git a/src/op_mode/container.py b/src/op_mode/container.py
index fe81636d2..feb9f41cc 100755
--- a/src/op_mode/container.py
+++ b/src/op_mode/container.py
@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import typing
 import json
 import sys
 import subprocess
@@ -63,7 +64,7 @@ def add_image(name: str):
     if do_logout:
         rc_cmd('podman logout --all')
 
-def delete_image(name: str):
+def delete_image(name: str, force: typing.Optional[bool] = False):
     from vyos.utils.process import rc_cmd
 
     if name == 'all':
@@ -73,9 +74,30 @@ def delete_image(name: str):
         if not name: return
         # replace newline with whitespace
         name = name.replace('\n', ' ')
-    rc, output = rc_cmd(f'podman image rm {name}')
-    if rc != 0:
-        raise vyos.opmode.InternalError(output)
+        # convert to list
+        name = name.split()
+
+    for image in name:
+        # convert the truncated image ID to a full image ID
+        rc, ancestor = rc_cmd(f'podman inspect {image} --format "{{{{.Id}}}}"')
+        if rc != 0:
+            raise vyos.opmode.InternalError(ancestor)
+        # check if the image ID is an ancestor of any running container
+        rc, in_use = rc_cmd(f'podman ps --filter ancestor={ancestor} -q')
+        if rc != 0:
+            raise vyos.opmode.InternalError(in_use)
+
+        if bool(in_use):
+            error = f'Cannot delete image "{image}" because it is currently '\
+                    f'being used by container "{in_use}"!'
+            raise vyos.opmode.InternalError(error)
+
+        tmp = f'podman image rm {image}'
+        if force: tmp += ' --force'
+
+        rc, output = rc_cmd(tmp)
+        if rc != 0:
+            raise vyos.opmode.InternalError(output)
 
 def show_container(raw: bool):
     command = 'podman ps --all'