Implemented config file processing

Configuration is taken from /etc/repa.conf and ~/.repa.conf, so it's
possible to specify system defaults in /etc/repa.conf and user-related
configuration options in ~/.repa.conf. ~/.repa.conf has higher priority
and any option from /etc/repa.conf can be reset in ~/.repa.conf

Configuration processing is implemented in a way that default values for
command line parameters are taken from configuration file(s).

Configuration section to use can be specified in command line too.

Fixes: #1141

Change-Id: I632f22674c282021983bc6a496ef1fccc0da3137
Signed-off-by: Ed Bartosh <eduard.bartosh@intel.com>
Reviewed-on: https://otctools.jf.intel.com/review/5839
Tested-by: OTC Tools Tester <ed.bartosh@linux.intel.com>
Reviewed-by: Hasan Wan <hasan.wan@intel.com>

6 files changed, 93 insertions, 15 deletions

diff --git a/packaging/repa.spec b/packaging/repa.spec
index bea2d0a..176d0b0 100644
--- a/packaging/repa.spec
+++ b/packaging/repa.spec
@@ -35,6 +35,7 @@ rm -rf %{buildroot}
 
 %files
 %defattr(-,root,root,-)
+%config %{_sysconfdir}/%{name}.conf
 %{_prefix}/share/doc/packages/%{name}
 %{python_sitelib}/%{name}-%{version}-*.egg-info
 %{python_sitelib}/%{name}-%{version}-*-nspkg.pth
diff --git a/repa.conf b/repa.conf
new file mode 100644
index 0000000..6e16037
--- /dev/null
+++ b/repa.conf
@@ -0,0 +1,9 @@
+[general]
+#apiurl =
+#apiuser =
+#apipasswd =
+list_regexp = .*
+
+[tizen.org]
+apiurl = https://api.tizen.org
+
diff --git a/repa/group.py b/repa/group.py
index 4d8140f..0c3089a 100755
--- a/repa/group.py
+++ b/repa/group.py
@@ -23,7 +23,7 @@ class Group(object):
     help = description
 
     @staticmethod
-    def add_arguments(parser):
+    def add_arguments(parser, _config):
         """Adds arguments to the parser. Called from [sub_]main."""
         parser.add_argument('--comment', help='comment')
 
diff --git a/repa/list.py b/repa/list.py
index 6359502..e8c493b 100755
--- a/repa/list.py
+++ b/repa/list.py
@@ -23,9 +23,13 @@ class List(object):
     help = description
 
     @staticmethod
-    def add_arguments(parser):
-        """Adds arguments to the parser. Called from [sub_]main."""
-        parser.add_argument('-regexp', default='.*', help='search regexp')
+    def add_arguments(parser, config):
+        """
+        Add arguments to the parser. Called from [sub_]main.
+        Set defaults for arguments from config.
+        """
+        parser.add_argument('-regexp', help='search regexp',
+                            default=config.get('list_regexp', '.*'))
 
     def run(self, argv):
         """Command line entry point. Called from [sub_]main"""
diff --git a/repa/main.py b/repa/main.py
index 7dc63b8..1f1c402 100755
--- a/repa/main.py
+++ b/repa/main.py
@@ -13,13 +13,32 @@ Command line parsing, script entry point.
 
 import sys
 import pkg_resources
+import ConfigParser
 
+from os.path import expanduser
 from argparse import ArgumentParser
 
+class RepaException(Exception):
+    """Custom repa exception. All repa modules should use it."""
+    pass
+
+
 def parse_args(argv):
-    """Command line parsing."""
-    parser = ArgumentParser(description='Release Engineering Process Assistant')
+    """
+    Parse command line. Read config.
+    Set arguments to config values.
+    """
+    # create parser to parse -section
+    parser = ArgumentParser(add_help=False)
+    parser.add_argument('-section', default='general',
+                        help='config section to use')
 
+    # read config section, specified in command line
+    parsed, argv = parser.parse_known_args(argv)
+    config = read_config(section=parsed.section)
+
+    # recreate parser to parse rest of the command line
+    parser = ArgumentParser(description='Release Engineering Process Assistant')
     # Define subcommands using setup.py entry points
     subparsers = parser.add_subparsers(help='sub-command help')
     for entry in pkg_resources.iter_entry_points(group='repa_commands'):
@@ -28,16 +47,56 @@ def parse_args(argv):
                                            description=cmd.description,
                                            help=cmd.help)
         if hasattr(cmd, 'add_arguments'):
-            cmd.add_arguments(parser_cmd)
+            cmd.add_arguments(parser_cmd, config)
         parser_cmd.set_defaults(func=cmd.run)
 
-    return parser.parse_args(argv)
+    args = parser.parse_args(argv)
+
+    return update_args(config, args)
+
+
+def read_config(paths=('/etc/repa.conf', expanduser('~/.repa.conf')),
+                section='general',
+                mandatory=('apiurl', 'apiuser', 'apipasswd')):
+    """
+    Read repa config.
+    Configuration is read from the set of files provided.
+    Optional section name can be specified to read options from
+    """
+    conf = ConfigParser.RawConfigParser()
+    if not conf.read(paths):
+        raise RepaException("Configuration file not found")
+    if not conf.has_section(section):
+        raise RepaException("Section '%s' doesn't exist in config" % section)
+
+    # read configuration from 'general' and then from specified section
+    # to have defaults set properly
+    config = dict(conf.items('general'))
+    if section != 'general':
+        config.update(conf.items(section))
+
+    # Check mandatory config options
+    missed = set(mandatory).difference(set(config.keys()))
+    if missed:
+        raise RepaException("Missing mandatory config options: %s" % \
+                                ','.join(missed))
+    return config
+
+def update_args(config, args):
+    """Set configuration options as args attributes."""
+    for key, val in config.iteritems():
+        if not hasattr(args, key):
+            setattr(args, key, val)
+    return args
 
 def sub_main(argv, cmd):
     """Subcommand entry point."""
     parser = ArgumentParser(description=cmd.description)
-    cmd.add_arguments(parser)
-    return cmd.run(parser.parse_args(argv))
+    config = read_config()
+    cmd.add_arguments(parser, config)
+    args = parser.parse_args(argv)
+    return cmd.run(update_args(config, args))
+
 
 def main(argv=sys.argv[1:]):
     """Command line entry point."""
@@ -46,4 +105,7 @@ def main(argv=sys.argv[1:]):
 
 
 if __name__ == '__main__':
-    sys.exit(main(sys.argv[1:]))
+    try:
+        sys.exit(main(sys.argv[1:]))
+    except RepaException, error:
+        print >> sys.stderr, error
diff --git a/setup.py b/setup.py
index 6c38f90..a1f5e0f 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@ Author: Ed Bartosh <eduard.bartosh@intel.com>
 
 Setup module
 """
-
+import os
 from setuptools import setup
 
 setup(name = "repa",
@@ -18,10 +18,12 @@ setup(name = "repa",
       author_email = 'eduard.bartosh@intel.com',
       packages = ['repa'],
       namespace_packages = ['repa'],
-      data_files = [('share/doc/packages/repa/', ['README']),],
+      data_files = [
+          ('share/doc/packages/repa/', ['README']),
+          (['/etc', 'etc'][bool(os.getenv('VIRTUAL_ENV'))], ['repa.conf'])],
       entry_points = {
           'console_scripts': ['repa = repa.main:main'],
-	  'repa_commands':   ['list = repa.list:List',
-		              'group = repa.group:Group']
+          'repa_commands':   ['list = repa.list:List',
+                              'group = repa.group:Group']
       }
 )