added alembic script to resize url and slug columns to 191

Signed-off-by: Veeresh K <[email protected]>

Author: nmveeresh

mcpgateway/alembic/versions/878e287d2366_resize_url_and_slug_columns_to_191.py

@@ -0,0 +1,63 @@
+""""resize url and slug columns to 191"
+
+Revision ID: 878e287d2366
+Revises: 2f67b12600b4
+Create Date: 2025-10-08 09:08:35.363100
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import mysql
+
+# revision identifiers, used by Alembic.
+revision: str = '878e287d2366'
+down_revision: Union[str, Sequence[str], None] = '2f67b12600b4'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # Truncate existing values longer than 191 chars
+    op.execute("""
+        UPDATE gateways
+        SET slug = LEFT(slug, 191),
+            url = LEFT(url, 191)
+        WHERE LENGTH(slug) > 191 OR LENGTH(url) > 191;
+    """)
+
+    # Resize columns to String(191)
+    op.alter_column(
+        'gateways',
+        'slug',
+        existing_type=sa.String(length=255),
+        type_=sa.String(length=191),
+        existing_nullable=False
+    )
+    op.alter_column(
+        'gateways',
+        'url',
+        existing_type=sa.String(length=767),
+        type_=sa.String(length=191),
+        existing_nullable=False
+    )
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    op.alter_column(
+        'gateways',
+        'slug',
+        existing_type=sa.String(length=191),
+        type_=sa.String(length=255),
+        existing_nullable=False
+    )
+    op.alter_column(
+        'gateways',
+        'url',
+        existing_type=sa.String(length=191),
+        type_=sa.String(length=767),
+        existing_nullable=False
+    )