Improved cookiecutter generating

Change-Id: Iaf4b92518d33a8416ac4a6337b51c718e5240494
diff --git a/src/com/mirantis/mk/Python.groovy b/src/com/mirantis/mk/Python.groovy
index 59bf9ee..c3e75f3 100644
--- a/src/com/mirantis/mk/Python.groovy
+++ b/src/com/mirantis/mk/Python.groovy
@@ -231,7 +231,7 @@
     configFile = "default_config.yaml"
     configString = "default_context:\n"
     writeFile file: configFile, text: context
-    command = ". ${path}/bin/activate; cookiecutter --config-file ${configFile} --output-dir ${outputDir} --overwrite-if-exists --verbose --no-input ${template}"
+    command = "if [ -f generate.py ]; then python generate.py --config-file ${configFile} --template ${template}; else source ${path}/bin/activate; cookiecutter --config-file ${configFile} --output-dir ${outputDir} --overwrite-if-exists --verbose --no-input ${template}; fi"
     output = sh (returnStdout: true, script: command)
     echo("[Cookiecutter build] Output: ${output}")
 }