Modify sql code to user the python virtualenv

src/pg/sql/01_py.sql

@@ -0,0 +1,18 @@
+-- Use the crankshaft python module
+CREATE OR REPLACE FUNCTION _cdb_crankshaft_activate_py()
+RETURNS VOID
+AS $$
+    # activate virtualenv
+    # TODO: parameterize with environment variables or something
+    venv_path = '/home/ubuntu/crankshaft/src/py/dev'
+    activate_path = venv_path + '/bin/activate_this.py'
+    exec(open(activate_path).read(),
+         dict(__file__=activate_path))
+
+    # import something from virtualenv
+    # from crankshaft import random_seeds
+
+    # do some stuff
+    # random_seeds.set_random_seeds(123)
+    # plpy.notice('here we are')
+$$ LANGUAGE plpythonu;

src/pg/sql/02_random_seeds.sql

@@ -4,6 +4,7 @@
 CREATE OR REPLACE FUNCTION
 _cdb_random_seeds (seed_value INTEGER) RETURNS VOID
 AS $$
+  plpy.execute('SELECT cdb_crankshaft._cdb_crankshaft_activate_py()')
   from crankshaft import random_seeds
   random_seeds.set_random_seeds(seed_value)
 $$ LANGUAGE plpythonu;

src/pg/sql/10_moran.sql

@@ -11,6 +11,7 @@ CREATE OR REPLACE FUNCTION
       w_type TEXT DEFAULT 'knn')
 RETURNS TABLE (moran FLOAT, quads TEXT, significance FLOAT, ids INT)
 AS $$
+  plpy.execute('SELECT cdb_crankshaft._cdb_crankshaft_activate_py()')
   from crankshaft.clustering import moran_local
   # TODO: use named parameters or a dictionary
   return moran_local(t, attr, significance, num_ngbrs, permutations, geom_column, id_col, w_type)
@@ -29,6 +30,7 @@ CREATE OR REPLACE FUNCTION
 		 w_type TEXT DEFAULT 'knn')
 RETURNS TABLE(moran FLOAT, quads TEXT, significance FLOAT, ids INT, y numeric)
 AS $$
+  plpy.execute('SELECT cdb_crankshaft._cdb_crankshaft_activate_py()')
   from crankshaft.clustering import moran_local_rate
   # TODO: use named parameters or a dictionary
   return moran_local_rate(t, numerator, denominator, significance, num_ngbrs, permutations, geom_column, id_col, w_type)