Added script to populate instance_flavor_id

in InstanceUsage, InstanceExists and InstanceReconcile
using instance_type_id-to-instance_flavor_id csv mapping

scripts/migrate_instance_flavor_id.py

@@ -0,0 +1,56 @@
+#!/usr/bin/python
+import os
+import sys
+
+sys.path.append(os.environ.get('STACKTACH_INSTALL_DIR', '/stacktach'))
+
+import csv
+from stacktach import models
+
+
+def migrate_forwards(csv_file_path):
+    with open(csv_file_path, "r") as f:
+        for old_flavor, new_flavor in csv.reader(f):
+            models.InstanceUsage.objects.filter(
+                instance_type_id=old_flavor, instance_flavor_id=None)\
+                .update(instance_flavor_id=new_flavor)
+            models.InstanceExists.objects.filter(
+                instance_type_id=old_flavor, instance_flavor_id=None)\
+                .update(instance_flavor_id=new_flavor)
+            models.InstanceReconcile.objects.filter(
+                instance_type_id=old_flavor, instance_flavor_id=None)\
+                .update(instance_flavor_id=new_flavor)
+
+
+def migrate_backwards(csv_file_path):
+    with open(csv_file_path, "r") as f:
+        for old_flavor, new_flavor in csv.reader(f):
+            models.InstanceUsage.objects.filter(instance_flavor_id=new_flavor)\
+                .update(instance_flavor_id=None)
+            models.InstanceExists.objects.filter(instance_flavor_id=new_flavor)\
+                .update(instance_flavor_id=None)
+            models.InstanceReconcile.objects.filter(
+                instance_flavor_id=new_flavor)\
+                .update(instance_flavor_id=None)
+
+if __name__ == '__main__':
+    try:
+        csv_file_path = sys.argv[1]
+        action = sys.argv[2]
+    except Exception:
+        print ("""usage: migrate_flavor_id.py <csv_file_absolute_path>"""
+                """ <forwards | backwards>"""
+                """\n\nThe input file for this script can be generated"""
+                """ using the following SQL query:"""
+                """\nSELECT id, flavorid"""
+                """\nINTO OUTFILE '/tmp/flavors.csv'"""
+                """\nFIELDS TERMINATED BY ','"""
+                """\nENCLOSED BY '"'"""
+                """\nLINES TERMINATED BY '\\n'"""
+                """\nFROM instance_types;""")
+        sys.exit(2)
+
+    if action == "forwards":
+        migrate_forwards(csv_file_path)
+    elif action == "backwards":
+        migrate_backwards(csv_file_path)