Merge branch 'add-config-option' of github.com:agyoungs/rocker into i…

…ntegration

setup.py

@@ -11,6 +11,7 @@
     'pexpect',
     'packaging',
     'urllib3',
+    'pyyaml',
 ]
 
 # docker API used to be in a package called `docker-py` before the 2.0 release

src/rocker/cli.py

@@ -15,6 +15,7 @@
 import argparse
 import os
 import sys
+import yaml
 
 from .core import DockerImageGenerator
 from .core import get_rocker_version
@@ -32,6 +33,10 @@ def main():
         formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.add_argument('image')
     parser.add_argument('command', nargs='*', default='')
+    parser.add_argument('--config', help='''Optional yaml file to handle command line arguments 
+        (except positional args) as a config file. This config will override any other command line 
+        arguments of the same name as the yaml keys (e.g. "--user-override-name" would have the key 
+        "user_override_name" in the config file)''')
     parser.add_argument('--noexecute', action='store_true', help='Deprecated')
     parser.add_argument('--nocache', action='store_true')
     parser.add_argument('--nocleanup', action='store_true', help='do not remove the docker container when stopped')
@@ -50,6 +55,12 @@ def main():
     args = parser.parse_args()
     args_dict = vars(args)
 
+    # Load config file if provided
+    if args.config:
+        with open(args.config, 'r') as f:
+            config = yaml.safe_load(f)
+        args_dict.update(config)
+
     if args.noexecute:
         from .core import OPERATIONS_DRY_RUN
         args_dict['mode'] = OPERATIONS_DRY_RUN