Adding Range Support to Salt

Range is a cluster based metadata store.  It was used internally at
yahoo and recently open source.  You can read about range here:

https://github.com/grierj/range/wiki/Introduction-to-Range-with-YAML-files

Range allows arbitrary grouping of hosts via clusters and the storage
of metadata along with them.  Additionally there is a powerful DSL that
allows for set operations, regexes, and multilayer cluster referencing.

The implementation here runs the range query and reduces it to a list
style expression format, which means only the salt master needs to know
about range or have the range libraries installed.

conf/master.template

@@ -202,3 +202,8 @@
 #   group1: 'L@foo.domain.com,bar.domain.com,baz.domain.com and bl*.domain.com',
 #   group2: 'G@os:Debian and foo.domain.com',
 
+#####     Range Cluster settings     #####
+##########################################
+# The range server (and optional port) that
+# serves your cluster information
+#range_server: range:80

salt/__init__.py

@@ -171,7 +171,7 @@ class Master(object):
                 # Late import so logging works correctly
                 import salt.utils
                 salt.utils.daemonize()
-            set_pidfile(self.cli['pidfile'])
+            set_pidfile(self.opts['pidfile'])
             try:
                 master.start()
             except salt.master.MasterExit:

salt/cli/__init__.py

@@ -112,6 +112,14 @@ class SaltCMD(object):
                 help=('Instead of using shell globs to evaluate the target '
                       'use one of the predefined nodegroups to identify a '
                       'list of targets.'))
+        parser.add_option('-R',
+                '--range',
+                default=False,
+                dest='range',
+                action='store_true',
+                help=('Instead of using shell globs to evaluate the target '
+                      'use a range expressions to identify targets. '
+                      'Range expressions look like %cluster'))
         parser.add_option('-C',
                 '--compound',
                 default=False,
@@ -270,6 +278,8 @@ class SaltCMD(object):
                 args.append('exsel')
             elif self.opts['nodegroup']:
                 args.append('nodegroup')
+            elif self.opts['range']:
+                args.append('range')
             elif self.opts['compound']:
                 args.append('compound')
             else:
@@ -413,6 +423,14 @@ class SaltCP(object):
                 help=('Instead of using shell globs to evaluate the target '
                       'use one of the predefined nodegroups to identify a '
                       'list of targets.'))
+        parser.add_option('-R',
+                '--range',
+                default=False,
+                dest='range',
+                action='store_true',
+                help=('Instead of using shell globs to evaluate the target '
+                      'use a range expressions to identify targets. '
+                      'Range expressions look like %cluster'))
         parser.add_option('-c',
                 '--config',
                 default='/etc/salt/master',

salt/cli/cp.py

@@ -78,6 +78,8 @@ class SaltCP(object):
             args.append('grain_pcre')
         elif self.opts['nodegroup']:
             args.append('nodegroup')
+        elif self.opts['range']:
+            args.append('range')
 
         ret = local.cmd(*args)
 

salt/client.py

@@ -44,6 +44,14 @@ import salt.config
 import salt.payload
 from salt.exceptions import SaltClientError, SaltInvocationError
 
+# Try to import range from https://github.com/ytoolshed/range
+RANGE = False
+try:
+  import seco.range
+  RANGE = True
+except ImportError:
+  pass
+
 
 def prep_jid(cachedir):
     '''
@@ -150,6 +158,14 @@ class LocalClient(object):
         '''
         return os.listdir(os.path.join(self.opts['pki_dir'], 'minions'))
 
+    def _convert_range_to_list(self, tgt):
+        range = seco.range.Range(self.opts['range_server'])
+        try:
+          return range.expand(tgt)
+        except seco.range.RangeException, e:
+          print "Range server exception: %s" % e
+          return []
+
     def gather_job_info(self, jid, tgt, tgt_type):
         '''
         Return the information about a given job
@@ -615,6 +631,12 @@ class LocalClient(object):
             tgt = self.opts['nodegroups'][tgt]
             expr_form = 'compound'
 
+        # Convert a range expression to a list of nodes and change expression
+        # form to list
+        if expr_form == 'range' and RANGE:
+          tgt = self._convert_range_to_list(tgt)
+          expr_form = 'list'
+
         # Run a check_minions, if no minions match return False
         # format the payload - make a function that does this in the payload
         #   module

salt/config.py

@@ -229,6 +229,7 @@ def master_config(path):
             'pidfile': '/var/run/salt-master.pid',
             'cluster_masters': [],
             'cluster_mode': 'paranoid',
+            'range_server': 'range:80',
             'serial': 'msgpack',
             'nodegroups': {},
             'key_logfile': '/var/log/salt/key.log',