better handling for default networks (#42)

* better handling for default networks

* fix for issues/43

* check for none explictly rather than allowing truthy/falsy conversion

* update to read volume data from mounts, rather than host config binds

Co-authored-by: Adam Doussan <acdoussan@Adams-MacBook-Pro.local>

autocompose.py

@@ -27,8 +27,16 @@ def main():
         cfile, c_networks, c_volumes = generate(cname)
 
         struct.update(cfile)
-        networks.update(c_networks)
-        volumes.update(c_volumes)
+
+        if c_networks is None:
+            networks = None
+        else:
+            networks.update(c_networks)
+
+        if c_volumes is None:
+            volumes = None
+        else:
+            volumes.update(c_volumes)
 
     render(struct, args, networks, volumes)
 
@@ -38,7 +46,15 @@ def render(struct, args, networks, volumes):
     if args.version == 1:
         pyaml.p(OrderedDict(struct))
     else:
-        pyaml.p(OrderedDict({'version': '"3"', 'services': struct, 'networks': networks, 'volumes': volumes}))
+        ans = {'version': '"3"', 'services': struct}
+
+        if networks is not None:
+            ans['networks'] = networks
+
+        if volumes is not None:
+            ans['volumes'] = volumes
+
+        pyaml.p(OrderedDict(ans))
 
 
 def is_date_or_time(s: str):
@@ -73,6 +89,8 @@ def generate(cname):
     cfile[cattrs['Name'][1:]] = {}
     ct = cfile[cattrs['Name'][1:]]
 
+    default_networks = ['bridge', 'host', 'none']
+
     values = {
         'cap_add': cattrs['HostConfig']['CapAdd'],
         'cap_drop': cattrs['HostConfig']['CapDrop'],
@@ -89,10 +107,10 @@ def generate(cname):
         #'log_driver': cattrs['HostConfig']['LogConfig']['Type'],
         #'log_opt': cattrs['HostConfig']['LogConfig']['Config'],
         'logging': {'driver': cattrs['HostConfig']['LogConfig']['Type'], 'options': cattrs['HostConfig']['LogConfig']['Config']},
-        'networks': {x for x in cattrs['NetworkSettings']['Networks'].keys() if x != 'bridge'},
+        'networks': {x for x in cattrs['NetworkSettings']['Networks'].keys() if x not in default_networks},
         'security_opt': cattrs['HostConfig']['SecurityOpt'],
         'ulimits': cattrs['HostConfig']['Ulimits'],
-        'volumes': cattrs['HostConfig']['Binds'],
+        'volumes': [f'{m["Name"]}:{m["Destination"]}' for m in cattrs['Mounts'] if m['Type'] == 'volume'],
         'volume_driver': cattrs['HostConfig']['VolumeDriver'],
         'volumes_from': cattrs['HostConfig']['VolumesFrom'],
         'entrypoint': cattrs['Config']['Entrypoint'],
@@ -116,6 +134,9 @@ def generate(cname):
     networks = {}
     if values['networks'] == set():
         del values['networks']
+        assumed_default_network = list(cattrs['NetworkSettings']['Networks'].keys())[0]
+        values['network_mode'] = assumed_default_network
+        networks = None
     else:
         networklist = c.networks.list()
         for network in networklist:
@@ -124,9 +145,12 @@ def generate(cname):
                                                    'name': network.attrs['Name']}
 
     volumes = {}
-    for volume in values['volumes']:
-        volume_name = volume.split(':')[0]
-        volumes[volume_name] = {'external': True}
+    if values['volumes'] is not None:
+        for volume in values['volumes']:
+            volume_name = volume.split(':')[0]
+            volumes[volume_name] = {'external': True}
+    else:
+        volumes = None
 
     # Check for command and add it if present.
     if cattrs['Config']['Cmd'] is not None: