config: Abolish use of ConfigParser's DEFAULT feature

ConfigParser provides no way to find out which sections a key is
_really_ in: in all of its views, keys in DEFAULT appear aliased in
all sections.

So instead we use a COMMON section, and implement the defaulting
ourselves.  This involves:

* Changing the cfg.get[int] calls to use cfg_search (these are
  the things which implictly use DEFAULT and now need to be
  explicit).
* Changing all our explicit references to and definitions of
  DEFAULT options to COMMON.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/README.config b/README.config
index 81f791d..2b58512 100644 (file)
--- a/README.config
+++ b/README.config
@@ -5,7 +5,7 @@ Sections
   [<servername> - <client>]
   [<client>]
   [<servername>]      often [SERVER]
-  [DEFAULT]
+  [COMMON]
 
 Keys are looked up in that order, unless otherwise specified.
 <client> is the client's virtual address.
@@ -15,7 +15,7 @@ Exceptional settings:
 
   server
      Specifies <servername>.
-     Is looked up in [SERVER] and [DEFAULT] only.
+     Is looked up in [SERVER] and [COMMON] only.
      If not specified there, it is SERVER.
 
      Used by server to select the appropriate parts of the
@@ -54,7 +54,7 @@ Exceptional settings:
 Capped settings:
 
      Values in [<server> LIMIT] and [LIMIT] are a cap (maximum) on
-     those from the other sections (including DEFAULT).
+     those from the other sections (including COMMON).
 
   max_batch_down
      Size limit for response payloads (used by server only)

diff --git a/hippotatd b/hippotatd
index c03ae48..0482876 100755 (executable)
--- a/hippotatd
+++ b/hippotatd
@@ -325,7 +325,7 @@ def process_cfg(_opts, putative_servers, putative_clients):
   except NoOptionError: pass
 
   cfg_process_ipif(c,
-                   [c.server, 'DEFAULT'],
+                   [c.server, 'COMMON'],
                    (('local','vaddr'),
                     ('peer', 'vrelay'),
                     ('rnets','vnetwork')))

diff --git a/hippotatlib/__init__.py b/hippotatlib/__init__.py
index ce94a86..8e00c15 100644 (file)
--- a/hippotatlib/__init__.py
+++ b/hippotatlib/__init__.py
@@ -126,7 +126,7 @@ class LogNotBoringTwisted:
 #---------- default config ----------
 
 defcfg = '''
-[DEFAULT]
+[COMMON]
 max_batch_down = 65536
 max_queue_time = 10
 target_requests_outstanding = 3
@@ -389,8 +389,8 @@ def _cfg_process_putatives():
   serverclient_re = regexp.compile(server_pat + r' ' + client_pat)
 
   for cs in cfg.sections():
-    if cs == 'LIMIT':
-      # plan A "[LIMIT]"
+    if cs == 'LIMIT' or cs == 'COMMON':
+      # plan A "[LIMIT]" or "[COMMON]"
       continue
 
     try:
@@ -492,11 +492,12 @@ def cfg_search(getter,key,sections):
   section = cfg_search_section(key,sections)
   return getter(section, key)
 
-def cfg1get(*args, **kwargs):
-  return cfg.get(*args, **kwargs)
+def cfg1get(section,key, getter=cfg.get,**kwargs):
+  section = cfg_search_section(key,[section,'COMMON'])
+  return getter(section,key,**kwargs)
 
-def cfg1getint(*args, **kwargs):
-  return cfg.getint(*args, **kwargs)
+def cfg1getint(section,key, **kwargs):
+  return cfg1get(section,key, getter=cfg.getint,**kwargs);
 
 def cfg_process_client_limited(cc,ss,sections,key):
   val = cfg_search(cfg1getint, key, sections)
@@ -510,7 +511,7 @@ def cfg_process_client_common(cc,ss,cs,ci):
   sections = ['%s %s' % (ss,cs),
               cs,
               ss,
-              'DEFAULT']
+              'COMMON']
 
   try: pwsection = cfg_search_section('password', sections)
   except NoOptionError: return None