- added timestamp-based JSON caching of configuration for faster loading

[invirt/packages/invirt-base.git] / files / usr / sbin / invirt-getconf

diff --git a/files/usr/sbin/invirt-getconf b/files/usr/sbin/invirt-getconf
index c468499..d503dea 100755 (executable)
--- a/files/usr/sbin/invirt-getconf
+++ b/files/usr/sbin/invirt-getconf
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.5
+#!/usr/bin/env python
 
 """
 invirt-getconf [-f FILE] KEY prints the configuration the option named KEY from
@@ -19,39 +19,49 @@ from invirt.config import load
 from sys import argv, exit, stderr
 from optparse import OptionParser
 
-class invirt_exception( Exception ): pass
+class invirt_exception(Exception): pass
 
-def main( argv ):
+def main(argv):
     try:
-        parser = OptionParser()
-        parser.add_option('-f', '--file', default = '/etc/invirt/master.yaml',
-                help = 'the configuration file to read from')
-        options, args = parser.parse_args()
+        parser = OptionParser(usage = '%prog [options] key',
+                description = __doc__.strip().split('\n\n')[0])
+        parser.add_option('-s', '--src',
+                default = '/etc/invirt/master.yaml',
+                help = 'the source YAML configuration file to read from')
+        parser.add_option('-c', '--cache',
+                default = '/var/lib/invirt/invirt.json',
+                help = 'path to the JSON cache')
+        parser.add_option('-r', '--refresh',
+                action = 'store_true',
+                help = 'force the cache to be regenerated')
+        opts, args = parser.parse_args()
 
         try: [key] = args
-        except: raise invirt_exception( __doc__ )
+        except: raise invirt_exception(__doc__.strip())
 
-        conf = load()
+        conf = load(opts.src, opts.cache, opts.refresh)
         components = key.split('.')
-        for i, component in enumerate( components ):
-            progress = lambda: '.'.join( components[:i] )
-            if type( conf ) not in [ dict, list ]:
+        for i, component in enumerate(components):
+            progress = '.'.join(components[:i])
+            if type(conf) not in [dict, list]:
                 raise invirt_exception(
-                        'prematurely arrived at an atomic datum in the tree:\n'
-                        '%s has no children' % progress() )
-            if type( conf ) == list:
-                try: component = int( component )
+                        '%s: node has no children (atomic datum)' % progress)
+            if type(conf) == list:
+                try: component = int(component)
                 except: raise invirt_exception(
-                        '%s is a list, requires an integral path component '
-                        'but got "%s"' % ( progress(), component ) )
-            try: conf = conf[ component ]
+                        '%s: node a list; integer path component required, '
+                        'but got "%s"' % (progress, component))
+            try: conf = conf[component]
             except KeyError: raise invirt_exception(
-                    '"%s" not in "%s"' % ( component, progress() ) )
+                    '%s: key "%s" not found' % (progress, component))
+            except IndexError: raise invirt_exception(
+                    '%s: index %s out of range' % (progress, component))
         print conf
-    except invirt_exception, ex:
+    except (invirt_exception, OSError), ex:
         print >> stderr, ex
         return 1
 
-if __name__ == '__main__': exit( main( argv ) )
+if __name__ == '__main__':
+    exit(main(argv))
 
 # vim:et:sw=4:ts=4