Support named constraints for multiple backends

Supporting multiple backends requires that specific sqlite
collations are not used, thus lowercase is applied to all non
case-sensitive columns. However, lowercasing the database requires
temporary disabling foreign key constraints, which is not possible
on SQLite and requires we specify the constraint names.

This migration specific to sqlite and postgresql drops every
constraint, whether it is named or not, and recreates all of them
with known names so we can later disable them.

core/admin/mailu/models.py

@@ -24,7 +24,7 @@ class IdnaDomain(db.TypeDecorator):
     """ Stores a Unicode string in it's IDNA representation (ASCII only)
     """
 
-    impl = db.String(80, collation="NOCASE")
+    impl = db.String(80)
 
     def process_bind_param(self, value, dialect):
         return idna.encode(value).decode("ascii").lower()
@@ -37,7 +37,7 @@ class IdnaEmail(db.TypeDecorator):
     """ Stores a Unicode string in it's IDNA representation (ASCII only)
     """
 
-    impl = db.String(255, collation="NOCASE")
+    impl = db.String(255)
 
     def process_bind_param(self, value, dialect):
         try:
@@ -88,32 +88,39 @@ class JSONEncoded(db.TypeDecorator):
         return json.loads(value) if value else None
 
 
-class Config(db.Model):
-    """ In-database configuration values
-    """
-
-    name = db.Column(db.String(255), primary_key=True, nullable=False)
-    value = db.Column(JSONEncoded)
-
-
-# Many-to-many association table for domain managers
-managers = db.Table('manager',
-    db.Column('domain_name', IdnaDomain, db.ForeignKey('domain.name')),
-    db.Column('user_email', IdnaEmail, db.ForeignKey('user.email'))
-)
-
-
 class Base(db.Model):
     """ Base class for all models
     """
 
     __abstract__ = True
 
+    metadata = sqlalchemy.schema.MetaData(
+        naming_convention={
+            "fk": "%(table_name)s_%(column_0_name)s_fkey",
+            "pk": "%(table_name)s_pkey"
+        }
+    )
+
     created_at = db.Column(db.Date, nullable=False, default=datetime.now)
     updated_at = db.Column(db.Date, nullable=True, onupdate=datetime.now)
     comment = db.Column(db.String(255), nullable=True)
 
 
+# Many-to-many association table for domain managers
+managers = db.Table('manager', Base.metadata,
+    db.Column('domain_name', IdnaDomain, db.ForeignKey('domain.name')),
+    db.Column('user_email', IdnaEmail, db.ForeignKey('user.email'))
+)
+
+
+class Config(Base):
+    """ In-database configuration values
+    """
+
+    name = db.Column(db.String(255), primary_key=True, nullable=False)
+    value = db.Column(JSONEncoded)
+
+
 class Domain(Base):
     """ A DNS domain that has mail addresses associated to it.
     """
@@ -309,7 +316,7 @@ class User(Base, Email):
     # Settings
     displayed_name = db.Column(db.String(160), nullable=False, default="")
     spam_enabled = db.Column(db.Boolean(), nullable=False, default=True)
-    spam_threshold = db.Column(db.Integer(), nullable=False, default=80.0)
+    spam_threshold = db.Column(db.Integer(), nullable=False, default=80)
 
     # Flask-login attributes
     is_authenticated = True

core/admin/migrations/env.py

@@ -22,7 +22,9 @@ logger = logging.getLogger('alembic.env')
 from flask import current_app
 config.set_main_option('sqlalchemy.url',
                        current_app.config.get('SQLALCHEMY_DATABASE_URI'))
-target_metadata = current_app.extensions['migrate'].db.metadata
+#target_metadata = current_app.extensions['migrate'].db.metadata
+from mailu import models
+target_metadata = models.Base.metadata
 
 # other values from the config, defined by the needs of env.py,
 # can be acquired:

core/admin/migrations/versions/546b04c886f0_.py

@@ -0,0 +1,79 @@
+""" Fix constraint naming by addint a name to all constraints
+
+Revision ID: 546b04c886f0
+Revises: 5aeb5811408e
+Create Date: 2018-12-08 16:33:37.757634
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '546b04c886f0'
+down_revision = 'cd79ed46d9c2'
+
+from alembic import op, context
+import sqlalchemy as sa
+
+
+def upgrade():
+    # Only run this for somehow supported data types at the date we started naming constraints
+    # Among others, these will probably fail on MySQL
+    if context.get_bind().engine.name not in ('sqlite', 'postgresql'):
+        return
+
+    metadata = context.get_context().opts['target_metadata']
+
+    # Drop every constraint on every table
+    with op.batch_alter_table('alias', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('alias_pkey', type_="primary")
+        batch_op.drop_constraint('alias_domain_name_fkey', type_="foreignkey")
+    with op.batch_alter_table('alternative', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('alternative_pkey', type_="primary")
+        batch_op.drop_constraint('alternative_domain_name_fkey', type_="foreignkey")
+    with op.batch_alter_table('manager', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('manager_domain_name_fkey', type_="foreignkey")
+        batch_op.drop_constraint('manager_user_email_fkey', type_="foreignkey")
+    with op.batch_alter_table('token', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('token_pkey', type_="primary")
+        batch_op.drop_constraint('token_user_email_fkey', type_="foreignkey")
+    with op.batch_alter_table('fetch', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('fetch_pkey', type_="primary")
+        batch_op.drop_constraint('fetch_user_email_fkey', type_="foreignkey")
+    with op.batch_alter_table('relay', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('relay_pkey', type_="primary")
+    with op.batch_alter_table('config', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('config_pkey', type_="primary")
+    with op.batch_alter_table('user', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('user_pkey', type_="primary")
+        batch_op.drop_constraint('user_domain_name_fkey', type_="foreignkey")
+    with op.batch_alter_table('domain', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.drop_constraint('domain_pkey', type_="primary")
+
+    # Recreate constraints with proper names
+    with op.batch_alter_table('domain', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_primary_key('domain_pkey', ['name'])
+    with op.batch_alter_table('alias', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_primary_key('alias_pkey', ['email'])
+        batch_op.create_foreign_key('alias_domain_name_fkey', 'domain', ['domain_name'], ['name'])
+    with op.batch_alter_table('user', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_primary_key('user_pkey', ['email'])
+        batch_op.create_foreign_key('user_domain_name_fkey', 'domain', ['domain_name'], ['name'])
+    with op.batch_alter_table('alternative', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_primary_key('alternative_pkey', ['name'])
+        batch_op.create_foreign_key('alternative_domain_name_fkey', 'domain', ['domain_name'], ['name'])
+    with op.batch_alter_table('manager', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_foreign_key('manager_domain_name_fkey', 'domain', ['domain_name'], ['name'])
+        batch_op.create_foreign_key('manager_user_email_fkey', 'user', ['user_email'], ['email'])
+    with op.batch_alter_table('token', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_primary_key('token_pkey', ['id'])
+        batch_op.create_foreign_key('token_user_email_fkey', 'user', ['user_email'], ['email'])
+    with op.batch_alter_table('fetch', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_primary_key('fetch_pkey', ['id'])
+        batch_op.create_foreign_key('fetch_user_email_fkey', 'user', ['user_email'], ['email'])
+    with op.batch_alter_table('relay', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_primary_key('relay_pkey', ['name'])
+    with op.batch_alter_table('config', naming_convention=metadata.naming_convention) as batch_op:
+        batch_op.create_primary_key('config_pkey', ['name'])
+
+
+def downgrade():
+    pass