Use factory to get the image classes

src/pylorax/__init__.py

@@ -367,12 +367,8 @@ class Lorax(BaseLoraxClass):
                             self.variant, self.basearch)
 
         # get the image class
-        if self.basearch == "ppc":
-            imgclass = images.PPC
-        elif self.basearch in ("i386", "x86_64"):
-            imgclass = images.X86
-        else:
-            raise Exception("not supported arch '{0}'".format(self.basearch))
+        factory = images.Factory()
+        imgclass = factory.get_class(self.basearch)
 
         i = imgclass(kernellist=self.outputtree.kernels,
                      installtree=self.installtree,

src/pylorax/images.py

@@ -667,3 +667,21 @@ class S390(object):
 
     def create_boot(self, efiboot=None):
         pass
+
+
+class Factory(object):
+
+    DISPATCH_MAP = {"ppc": PPC,
+                    "i386": X86,
+                    "x86_64": X86,
+                    "s390": S390,
+                    "s390x": S390}
+
+    def __init__(self):
+        pass
+
+    def get_class(self, arch):
+        if arch in self.DISPATCH_MAP:
+            return self.DISPATCH_MAP[arch]
+        else:
+            raise Exception("no support for {0}".format(arch))