make sfa really not depending on sfatables

diff --git a/sfa/util/sfatablesRuntime.py b/sfa/util/sfatablesRuntime.py
index 170fa88..ef8404b 100644 (file)
--- a/sfa/util/sfatablesRuntime.py
+++ b/sfa/util/sfatablesRuntime.py
@@ -1,36 +1,47 @@
-from sfatables.runtime import SFATablesRules
+# sfa should not depend on sfatables
+# if the sfatables.runtime import fails, just define run_sfatables as identity
 
-def fetch_context(slice_hrn, user_hrn, contexts):
-    """
-    Returns the request context required by sfatables. At some point, this
-    mechanism should be changed to refer to "contexts", which is the
-    information that sfatables is requesting. But for now, we just return
-    the basic information needed in a dict.
-    """
-    base_context = {'sfa':{'user':{'hrn':user_hrn}, 'slice':{'hrn':slice_hrn}}}
-    return base_context
+try:
+    from sfatables.runtime import SFATablesRules
 
-def run_sfatables(chain, hrn, origin_hrn, rspec, context_callback = None ):
-    """
-    Run the rspec through sfatables
-    @param chain Name of rule chain
-    @param hrn Object's hrn
-    @param origin_hrn Original caller's hrn
-    @param rspec Incoming rspec
-    @param context_callback Callback used to generate the request context  
+    def fetch_context(slice_hrn, user_hrn, contexts):
+        """
+        Returns the request context required by sfatables. At some point, this
+        mechanism should be changed to refer to "contexts", which is the
+        information that sfatables is requesting. But for now, we just return
+        the basic information needed in a dict.
+        """
+        base_context = {'sfa':{'user':{'hrn':user_hrn}, 'slice':{'hrn':slice_hrn}}}
+        return base_context
 
-    @return rspec
-    """
-    if not context_callback:
-        context_callback = fetch_context
+    def run_sfatables(chain, hrn, origin_hrn, rspec, context_callback = None ):
+        """
+        Run the rspec through sfatables
+        @param chain Name of rule chain
+        @param hrn Object's hrn
+        @param origin_hrn Original caller's hrn
+        @param rspec Incoming rspec
+        @param context_callback Callback used to generate the request context  
+        
+        @return rspec
+        """
+        if not context_callback:
+            context_callback = fetch_context
 
-    chain = chain.upper()
-    rules = SFATablesRules(chain)
-    if rules.sorted_rule_list:
-        contexts = rules.contexts
-        request_context = context_callback(hrn, origin_hrn, contexts)
-        rules.set_context(request_context)
-        newrspec = rules.apply(rspec)
-    else:
-        newrspec = rspec
-    return newrspec
+        chain = chain.upper()
+        rules = SFATablesRules(chain)
+        if rules.sorted_rule_list:
+            contexts = rules.contexts
+            request_context = context_callback(hrn, origin_hrn, contexts)
+            rules.set_context(request_context)
+            newrspec = rules.apply(rspec)
+        else:
+            newrspec = rspec
+        return newrspec
+
+except:
+    
+    from sfa.util.logging import logger
+    def run_sfatables (, rspec, ____):
+        logger.warning("Cannot import sfatables.runtime, please install package sfa-sfatables")
+        return rspec