ensure original_resource_id is not none

statsd resource doesn't have an original_resource_id so we need to
set it by copying over id during upgrade

Change-Id: Id516c5b1d091ca01688d6ad8cf1076a998d15333
Closes-Bug: #1662849
(cherry picked from commit 9b53bce0c5)

gnocchi/indexer/alembic/versions/1e1a63d3d186_original_resource_id_not_null.py

@@ -23,6 +23,8 @@ Create Date: 2017-01-26 19:33:35.209688
 
 from alembic import op
 import sqlalchemy as sa
+from sqlalchemy import func
+import sqlalchemy_utils
 
 
 # revision identifiers, used by Alembic.
@@ -32,8 +34,33 @@ branch_labels = None
 depends_on = None
 
 
+def clean_substr(col, start, length):
+    return func.lower(func.substr(func.hex(col), start, length))
+
+
 def upgrade():
+    bind = op.get_bind()
     for table_name in ('resource', 'resource_history'):
+        table = sa.Table(table_name, sa.MetaData(),
+                         sa.Column('id',
+                                   sqlalchemy_utils.types.uuid.UUIDType(),
+                                   nullable=False),
+                         sa.Column('original_resource_id', sa.String(255)))
+
+        # NOTE(gordc): mysql stores id as binary so we need to rebuild back to
+        # string uuid.
+        if bind and bind.engine.name == "mysql":
+            vals = {'original_resource_id':
+                    clean_substr(table.c.id, 1, 8) + '-' +
+                    clean_substr(table.c.id, 9, 4) + '-' +
+                    clean_substr(table.c.id, 13, 4) + '-' +
+                    clean_substr(table.c.id, 17, 4) + '-' +
+                    clean_substr(table.c.id, 21, 12)}
+        else:
+            vals = {'original_resource_id': table.c.id}
+
+        op.execute(table.update().where(
+            table.c.original_resource_id.is_(None)).values(vals))
         op.alter_column(table_name, "original_resource_id", nullable=False,
                         existing_type=sa.String(255),
                         existing_nullable=True)