Teach rcynicng to read command line defaults from rpki.conf. Some of

this takes the form of new rpki.config.parser methods which we may
want to use in other programs, particularly the daemons.

svn path=/branches/tk705/; revision=6345

1 files changed, 88 insertions, 7 deletions

diff --git a/rpki/config.py b/rpki/config.py
index 3cc16626..7550c8f4 100644
--- a/rpki/config.py
+++ b/rpki/config.py
@@ -77,8 +77,10 @@ class parser(object):
         allow_missing = kwargs.pop("allow_missing", False)
         set_filename  = kwargs.pop("set_filename",  None)
         filename      = kwargs.pop("filename",      set_filename)
+        argparser     = kwargs.pop("argparser",     None)
 
-        assert not kwargs, "Unexpected keyword arguments: " + ", ".join("%s = %r" % kv for kv in kwargs.iteritems())
+        assert not kwargs, "Unexpected keyword arguments: {}".format(
+            ", ".join("{} = {!r}".format(k, v) for k, v in kwargs.iteritems()))
 
         if set_filename is not None:
             os.environ[rpki_conf_envname] = set_filename
@@ -87,6 +89,7 @@ class parser(object):
         self.default_section = section
 
         self.filename = filename or os.getenv(rpki_conf_envname) or default_filename
+        self.argparser = argparser
 
         try:
             with open(self.filename, "r") as f:
@@ -129,7 +132,8 @@ class parser(object):
         if self.cfg.has_option(section, option):
             yield self.cfg.get(section, option)
         option += "."
-        matches = [o for o in self.cfg.options(section) if o.startswith(option) and o[len(option):].isdigit()]
+        matches = [o for o in self.cfg.options(section) 
+                   if o.startswith(option) and o[len(option):].isdigit()]
         matches.sort()
         for option in matches:
             yield self.cfg.get(section, option)
@@ -176,7 +180,7 @@ class parser(object):
         if isinstance(v, str):
             v = v.lower()
             if v not in self.cfg._boolean_states:
-                raise ValueError("Not a boolean: %s" % v)
+                raise ValueError("Not boolean: {}".format(v))
             v = self.cfg._boolean_states[v]
         return v
 
@@ -197,6 +201,80 @@ class parser(object):
         return long(self.get(option, default, section))
 
 
+    def add_argument(self, *names, **kwargs):
+        """
+        Combined command line and config file argument.  Takes
+        arguments mostly like ArgumentParser.add_argument(), but also
+        looks in config file for option of the same name.
+
+        The "section" and "default" arguments are used for the config file
+        lookup; the resulting value is used as the "default" parameter for 
+        the argument parser.
+
+        If a "type" argument is specified, it applies to both the value
+        parsed from the config file and the argument parser.
+        """
+
+        section = kwargs.pop("section", None)
+        default = kwargs.pop("default", None)
+
+        for name in names:
+            if name.startswith("--"):
+                name = name[2:]
+                break
+        else:
+            raise ValueError
+
+        default = self.get(name, default = default, section = section)
+
+        if "type" in kwargs:
+            default = kwargs["type"](default)
+
+        kwargs["default"] = default
+
+        return self.argparser.add_argument(*names, **kwargs)
+
+    def add_boolean_argument(self, name, **kwargs):
+        """
+        Combined command line and config file boolean argument.  Takes
+        arguments mostly like ArgumentParser.add_argument(), but also
+        looks in config file for option of the same name.
+
+        The "section" and "default" arguments are used for the config file
+        lookup; the resulting value is used as the default value for 
+        the argument parser.
+
+        Usage is a bit different from the normal ArgumentParser boolean
+        handling: because the command line default is controlled by the
+        config file, the "store_true" / "store_false" semantics don't
+        really work for us.  So, instead, we use the --foo / --no-foo
+        convention, and generate a pair of command line arguments with
+        those names controlling a single "foo" value in the result.
+        """
+
+        section = kwargs.pop("section", None)
+        default = kwargs.pop("default", None)
+
+        if not name.startswith("--"):
+            raise ValueError
+        name = name[2:]
+
+        default = self.getboolean(name, default = default, section = section)
+
+        kwargs["action"] = "store_const"
+        kwargs["dest"] = name.replace("-", "_")
+
+        group = self.argparser.add_mutually_exclusive_group()
+
+        kwargs["const"] = True
+        group.add_argument("--" + name, **kwargs)
+
+        kwargs["const"] = False
+        #kwargs["help"] = argparse.SUPPRESS
+        group.add_argument("--no-" + name, **kwargs)
+
+        self.argparser.set_defaults(**{ kwargs["dest"] : default })
+
     def set_global_flags(self):
         """
         Consolidated control for all the little global control flags
@@ -224,14 +302,16 @@ class parser(object):
             pass
 
         try:
-            rpki.x509.XML_CMS_object.dump_outbound_cms = rpki.x509.DeadDrop(self.get("dump_outbound_cms"))
+            rpki.x509.XML_CMS_object.dump_outbound_cms = rpki.x509.DeadDrop(
+                self.get("dump_outbound_cms"))
         except OSError, e:
             logger.warning("Couldn't initialize mailbox %s: %s", self.get("dump_outbound_cms"), e)
         except ConfigParser.NoOptionError:
             pass
 
         try:
-            rpki.x509.XML_CMS_object.dump_inbound_cms = rpki.x509.DeadDrop(self.get("dump_inbound_cms"))
+            rpki.x509.XML_CMS_object.dump_inbound_cms = rpki.x509.DeadDrop(
+                self.get("dump_inbound_cms"))
         except OSError, e:
             logger.warning("Couldn't initialize mailbox %s: %s", self.get("dump_inbound_cms"), e)
         except ConfigParser.NoOptionError:
@@ -323,10 +403,11 @@ def argparser(section = None, doc = None, cfg_optional = False):
 
     args, remaining_argv = cfgparser.parse_known_args()
 
+    argparser = argparse.ArgumentParser(parents = [topparser], description = doc)
+
     cfg = parser(section       = section,
                  set_filename  = args.config,
+                 argparser     = argparser,
                  allow_missing = cfg_optional or args.help)
 
-    argparser = argparse.ArgumentParser(parents = [topparser], description = doc)
-
     return cfg, argparser