Fix base channel discovery for local charms

`utils.get_local_charm_base()` was incorrectly using the `--channel`
argument (the charm's channel) for discovering the channel part of the
base. (we should stop using the word 'channel' for two different
things).

This fixes that by taking out the incorrect part of the code.

Should fix #839

Author: cderici

juju/model.py

@@ -1682,13 +1682,11 @@ async def deploy(
                 # We have a local charm dir that needs to be uploaded
                 charm_dir = os.path.abspath(os.path.expanduser(identifier))
                 charm_origin = res.origin
-                base = None
 
                 metadata = utils.get_local_charm_metadata(charm_dir)
                 charm_series = charm_series or await get_charm_series(metadata,
                                                                       self)
-                base = utils.get_local_charm_base(
-                    charm_series, channel, metadata, charm_dir, client.Base)
+                base = utils.get_local_charm_base(charm_series, charm_dir, client.Base)
                 charm_origin.base = base
                 if not application_name:
                     application_name = metadata['name']

juju/utils.py

@@ -329,46 +329,21 @@ def get_version_series(version):
     return list(UBUNTU_SERIES.keys())[list(UBUNTU_SERIES.values()).index(version)]
 
 
-def get_local_charm_base(series, channel_from_arg, charm_metadata,
-                         charm_path, baseCls):
+def get_local_charm_base(series, charm_path, base_class):
     """Deduce the base [channel/osname] of a local charm based on what we
     know already
 
     :param str series: This may come from the argument or the metadata.yaml
-    :param str channel_from_arg: This is channel passed as argument, if any.
-    :param dict charm_metadata: metadata.yaml
     :param str charm_path: Path of charm directory/.charm file
-    :param class baseCls:
+    :param class base_class:
     :return: Instance of the baseCls with channel/osname informaiton
     """
 
     channel_for_base = ''
     os_name_for_base = ''
-    # If user passed a channel_arg, then check the supported series against
-    # the channel's track
-    chnl_check = origin.Channel.parse(channel_from_arg) if channel_from_arg \
-        else None
-    if chnl_check:
-        not_supported_error = errors.JujuError(
-            "Given channel [track/risk] is not supported --"
-            "\n - Given channel : %s"
-            "\n - Series in Charm Metadata : %s" %
-            (channel_from_arg, charm_metadata['series']))
-        channel_for_base = chnl_check.track
-        intented_series = get_version_series(channel_for_base)
-        if intented_series not in charm_metadata['series']:
-            raise not_supported_error
-        # Also check the manifest if there's one
-        charm_manifest = get_local_charm_manifest(charm_path)
-        if 'bases' in charm_manifest:
-            for base in charm_manifest['bases']:
-                if channel_for_base == base['channel']:
-                    break
-            else:
-                raise not_supported_error
 
-    # If we know the series, use it to get a channel
-    if channel_for_base == '':
+    # We should know the series, so use it to get a channel
+    if series:
         channel_for_base = get_series_version(series) if series else ''
         if channel_for_base:
             # we currently only support ubuntu series (statically)
@@ -382,18 +357,19 @@ def get_local_charm_base(series, channel_from_arg, charm_metadata,
         if 'bases' in charm_manifest:
             channel_for_base = charm_manifest['bases'][0]['channel']
             os_name_for_base = charm_manifest['bases'][0]['name']
-        else:
-            # Also check the charmcraft.yaml
-            charmcraft_yaml = get_local_charm_charmcraft_yaml(charm_path)
-            if 'bases' in charmcraft_yaml:
-                channel_for_base = charmcraft_yaml['bases'][0]['run-on'][0]['channel']
-                os_name_for_base = charmcraft_yaml['bases'][0]['run-on'][0]['name']
+
+    # Also check the charmcraft.yaml
+    if channel_for_base == '':
+        charmcraft_yaml = get_local_charm_charmcraft_yaml(charm_path)
+        if 'bases' in charmcraft_yaml:
+            channel_for_base = charmcraft_yaml['bases'][0]['run-on'][0]['channel']
+            os_name_for_base = charmcraft_yaml['bases'][0]['run-on'][0]['name']
 
     if channel_for_base == '':
         raise errors.JujuError("Unable to determine base for charm : %s" %
                                charm_path)
 
-    return baseCls(channel_for_base, os_name_for_base)
+    return base_class(channel_for_base, os_name_for_base)
 
 
 def base_channel_to_series(channel):