add the initial code for the state execution

salt/state.py

@@ -0,0 +1,87 @@
+'''
+The module used to execute states in salt. A state is unlike a module execution
+in that instead of just executing a command it ensure that a certian state is
+present on the system.
+'''
+# Import python modules
+import sys
+import os
+import inspect
+# Import Salt modules
+import salt.loader
+
+class State(object):
+    '''
+    Class used to execute salt states
+    '''
+    def __init__(self, opts):
+        self.opts = opts
+        self.states = salt.loader.states(opts)
+
+    def verify_data(self, data):
+        '''
+        Verify the data, return an error statement if something is wrong
+        '''
+        errors = []
+        if not data.has_key('state')\
+                or not data.has_key('fun')\
+                or not data.has_key('name'):
+            return ret
+        for fun in data['fun']:
+            full = data['state'] + '.' + fun
+            if not self.states.has_key(full):
+                errors.append('Specified state ' + full + ' is unavailable.')
+                continue
+            aspec = inspect.getargspec(self.states[full])
+            for ind in range(len(aspec[0]) - len(aspec[3])):
+                if not data.has_key(aspec[0]):
+                    errors.append('Missing paramater ' + aspec[0]\
+                                + ' for state ' + full)
+        return errors
+
+    def format_call(self, data):
+        '''
+        Formats the data into a list of dicts used to acctually call the state,
+        returns:
+        {
+        'full': 'module.function',
+        'args': [arg[0], arg[1], ...]
+        }
+        used to call the function like this:
+        self.states[ret['full']](*ret['args'])
+
+        It is assumed that the passed data has already been verified with
+        verify_data
+        '''
+        ret = {}
+        ret['full'] = data['state'] + '.' + fun
+        ret['args'] = []
+        aspec = inspect.getargspec(self.states[full])
+        kwargs = {}
+        for ind in range(len(aspec[0] - 1, 0, -1)):
+            def_minus = len(aspec[0]) - ind
+            if len(aspec[3]) - def_minus > -1:
+                minus = def_minus + 1
+                kwargs[aspec[0][ind]] = aspec[3][-minus]
+        for arg in kwargs:
+            if data.has_key(arg):
+                kwargs[arg] = data['arg']
+        for arg in aspec[0]:
+            ret['args'].append(kwargs[arg])
+        return data
+
+    def call(self, data):
+        '''
+        Call a state
+        '''
+        ret = {'changes': None,
+               'result': False,
+               'comment': ''}
+        errors = self.verify_data(data)
+        if errors:
+            for line in errors:
+                ret['comment'] += line + '\n'
+                sys.stderr.write(line + '\n')
+            return ret
+        cdata = self.format_call(data)
+        return self.states[cdata['full']](*cdata['args'])