container: T2216: use defaultValue XML definition to define port prot…

…ocol

Instead of hardcoding the default protocol as TCP in the Python script we shall
use the XML based defaultValue approach instead. This also automatically exports
the default to the CLI completion helper.

interface-definitions/container.xml.in

@@ -207,14 +207,23 @@
               </leafNode>
               <leafNode name="protocol">
                 <properties>
-                  <help>Protocol tcp/udp</help>
+                  <help>Transport protocol used for port mapping</help>
                   <completionHelp>
                     <list>tcp udp</list>
                   </completionHelp>
+                  <valueHelp>
+                    <format>tcp</format>
+                    <description>Use Transmission Control Protocol for given port</description>
+                  </valueHelp>
+                  <valueHelp>
+                    <format>udp</format>
+                    <description>Use User Datagram Protocol for given port</description>
+                  </valueHelp>
                   <constraint>
                     <regex>(tcp|udp)</regex>
                   </constraint>
                 </properties>
+                <defaultValue>tcp</defaultValue>
               </leafNode>
             </children>
           </tagNode>

src/conf_mode/container.py

@@ -73,9 +73,19 @@ def get_config(config=None):
     # Merge per-container default values
     if 'name' in container:
         default_values = defaults(base + ['name'])
+        if 'port' in default_values:
+            del default_values['port']
         for name in container['name']:
             container['name'][name] = dict_merge(default_values, container['name'][name])
 
+            # XXX: T2665: we can not safely rely on the defaults() when there are
+            # tagNodes in place, it is better to blend in the defaults manually.
+            if 'port' in container['name'][name]:
+                for port in container['name'][name]['port']:
+                    default_values = defaults(base + ['name', 'port'])
+                    container['name'][name]['port'][port] = dict_merge(
+                        default_values, container['name'][name]['port'][port])
+
     # Delete container network, delete containers
     tmp = node_changed(conf, base + ['network'])
     if tmp: container.update({'network_remove' : tmp})
@@ -242,14 +252,10 @@ def generate_run_arguments(name, container_config):
     if 'port' in container_config:
         protocol = ''
         for portmap in container_config['port']:
-            if 'protocol' in container_config['port'][portmap]:
-                protocol = container_config['port'][portmap]['protocol']
-                protocol = f'/{protocol}'
-            else:
-                protocol = '/tcp'
+            protocol = container_config['port'][portmap]['protocol']
             sport = container_config['port'][portmap]['source']
             dport = container_config['port'][portmap]['destination']
-            port += f' -p {sport}:{dport}{protocol}'
+            port += f' -p {sport}:{dport}/{protocol}'
 
     # Bind volume
     volume = ''