Update README with note on how to validate output.

With somewhat-recent docker features and spec changes that have been included in the compose file generation for this script, specifying compose file version 3.6 (at least) is necessary for the output compose file to pass validation using "docker-compose config".

README.md

@@ -46,3 +46,7 @@ Use the new image to generate a docker-compose file from a running container or
 To print out all containers in a docker-compose format:
 
     docker run --rm -v /var/run/docker.sock:/var/run/docker.sock ghcr.io/red5d/docker-autocompose $(docker ps -aq)
+    
+## Contributing
+
+When making changes, please validate the output from the script by writing it to a file (docker-compose.yml or docker-compose.yaml) and running "docker-compose config" in the same folder with it to ensure that the resulting compose file will be accepted by docker-compose.

autocompose.py

@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 import datetime
 import sys, argparse, pyaml, docker
 from collections import OrderedDict
@@ -14,6 +14,7 @@ def main():
     parser.add_argument('-a', '--all', action='store_true', help='Include all active containers')
     parser.add_argument('-v', '--version', type=int, default=3, help='Compose file version (1 or 3)')
     parser.add_argument('cnames', nargs='*', type=str, help='The name of the container to process.')
+    parser.add_argument('-c', '--createvolumes', action='store_true', help='Create new volumes instead of reusing existing ones')
     args = parser.parse_args()
 
     container_names = args.cnames
@@ -23,30 +24,30 @@ def main():
     struct = {}
     networks = {}
     volumes = {}
+    containers = {}
     for cname in container_names:
-        cfile, c_networks, c_volumes = generate(cname)
+        cfile, c_networks, c_volumes = generate(cname, createvolumes=args.createvolumes)
 
         struct.update(cfile)
 
-        if c_networks is None:
-            networks = None
-        else:
+        if not c_networks == None:
             networks.update(c_networks)
-
-        if c_volumes is None:
-            volumes = None
-        else:
+        if not c_volumes == None:
             volumes.update(c_volumes)
     
+    # moving the networks = None statemens outside of the for loop. Otherwise any container could reset it.
+    if len(networks) == 0:
+    	networks = None
+    if len(volumes) == 0:
+    	volumes = None
     render(struct, args, networks, volumes)
 
-
 def render(struct, args, networks, volumes):
     # Render yaml file
     if args.version == 1:
         pyaml.p(OrderedDict(struct))
     else:
-        ans = {'version': '"3"', 'services': struct}
+        ans = {'version': '"3.6"', 'services': struct}
 
         if networks is not None:
             ans['networks'] = networks
@@ -71,7 +72,7 @@ def fix_label(label: str):
     return f"'{label}'" if is_date_or_time(label) else label
 
 
-def generate(cname):
+def generate(cname, createvolumes=False):
     c = docker.from_env()
 
     try:
@@ -110,7 +111,9 @@ def generate(cname):
         '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': [f'{m["Name"]}:{m["Destination"]}' for m in cattrs['Mounts'] if m['Type'] == 'volume'],
+# the line below would not handle type bind
+#        'volumes': [f'{m["Name"]}:{m["Destination"]}' for m in cattrs['Mounts'] if m['Type'] == 'volume'],
+        'mounts': cattrs['Mounts'], #this could be moved outside of the dict. will only use it for generate
         'volume_driver': cattrs['HostConfig']['VolumeDriver'],
         'volumes_from': cattrs['HostConfig']['VolumesFrom'],
         'entrypoint': cattrs['Config']['Entrypoint'],
@@ -143,14 +146,34 @@ def generate(cname):
             if network.attrs['Name'] in values['networks']:
                 networks[network.attrs['Name']] = {'external': (not network.attrs['Internal']),
                                                    'name': network.attrs['Name']}
+#     volumes = {}
+#     if values['volumes'] is not None:
+#         for volume in values['volumes']:
+#             volume_name = volume.split(':')[0]
+#             volumes[volume_name] = {'external': True}
+#     else:
+#         volumes = None
         
+    # handles both the returned values['volumes'] (in c_file) and volumes for both, the bind and volume types
+    # also includes the read only option
     volumes = {}
-    if values['volumes'] is not None:
-        for volume in values['volumes']:
-            volume_name = volume.split(':')[0]
-            volumes[volume_name] = {'external': True}
-    else:
+    mountpoints = []
+    if values['mounts'] is not None:
+        for mount in values['mounts']:
+            destination = mount['Destination']
+            if not mount['RW']:
+                destination = destination + ':ro'
+            if mount['Type'] == 'volume':
+                mountpoints.append(mount['Name'] + ':' + destination)
+                if not createvolumes:
+                    volumes[mount['Name']] = {'external': True}    #to reuse an existing volume ... better to make that a choice? (cli argument)
+            elif mount['Type'] == 'bind':
+                mountpoints.append(mount['Source'] + ':' + destination)
+        values['volumes'] = mountpoints
+    if len(volumes) == 0:
         volumes = None
+    values['mounts'] = None #remove this temporary data from the returned data
+
 
     # Check for command and add it if present.
     if cattrs['Config']['Cmd'] is not None:
@@ -186,4 +209,3 @@ def generate(cname):
 
 if __name__ == "__main__":
     main()
-