diff --git a/core/admin/Dockerfile b/core/admin/Dockerfile
index b7109977..33c0bde7 100644
--- a/core/admin/Dockerfile
+++ b/core/admin/Dockerfile
@@ -8,7 +8,7 @@ RUN mkdir -p /app
 WORKDIR /app
 
 COPY requirements-prod.txt requirements.txt
-RUN apk add --no-cache libressl curl postgresql-libs\
+RUN apk add --no-cache libressl curl postgresql-libs mariadb-connector-c \
  && apk add --no-cache --virtual build-dep \
  libressl-dev libffi-dev python3-dev build-base postgresql-dev mariadb-connector-c-dev \
  && pip3 install -r requirements.txt \
diff --git a/core/admin/migrations/env.py b/core/admin/migrations/env.py
index a3f9cf18..cdfd2248 100755
--- a/core/admin/migrations/env.py
+++ b/core/admin/migrations/env.py
@@ -72,7 +72,14 @@ def run_migrations_online():
     engine = engine_from_config(config.get_section(config.config_ini_section),
                                 prefix='sqlalchemy.',
                                 poolclass=pool.NullPool)
-    connection = retry(engine.connect, stop=tenacity.stop_after_attempt(100), wait=tenacity.wait_random(min=2, max=5))()
+
+    connection = tenacity.Retrying(
+        stop=tenacity.stop_after_attempt(100),
+        wait=tenacity.wait_random(min=2, max=5),
+        before=tenacity.before_log(logging.getLogger("tenacity.retry"), logging.DEBUG),
+        before_sleep=tenacity.before_sleep_log(logging.getLogger("tenacity.retry"), logging.INFO),
+        after=tenacity.after_log(logging.getLogger("tenacity.retry"), logging.DEBUG)
+        ).call(engine.connect)
 
     context.configure(connection=connection,
                       target_metadata=target_metadata,
diff --git a/core/admin/migrations/versions/049fed905da7_.py b/core/admin/migrations/versions/049fed905da7_.py
index 5398ad20..d8af41d3 100644
--- a/core/admin/migrations/versions/049fed905da7_.py
+++ b/core/admin/migrations/versions/049fed905da7_.py
@@ -16,10 +16,10 @@ import sqlalchemy as sa
 
 def upgrade():
     with op.batch_alter_table('user') as batch:
-        batch.alter_column('email', type_=sa.String(length=255))
+        batch.alter_column('email', type_=sa.String(length=255), nullable=False)
 
 
 def downgrade():
     with op.batch_alter_table('user') as batch:
-        batch.alter_column('email', type_=sa.String(length=255))
+        batch.alter_column('email', type_=sa.String(length=255), nullable=False)
 
diff --git a/core/admin/migrations/versions/5aeb5811408e_.py b/core/admin/migrations/versions/5aeb5811408e_.py
index 37a2c924..2ea06ea9 100644
--- a/core/admin/migrations/versions/5aeb5811408e_.py
+++ b/core/admin/migrations/versions/5aeb5811408e_.py
@@ -43,18 +43,18 @@ def upgrade():
 
     # drop foreign key constraints
     with op.batch_alter_table('alias') as batch_op:
-        batch_op.drop_constraint('alias_domain_name_fkey')
+        batch_op.drop_constraint('alias_domain_name_fkey', type_='foreignkey')
     with op.batch_alter_table('alternative') as batch_op:
-        batch_op.drop_constraint('alternative_domain_name_fkey')
+        batch_op.drop_constraint('alternative_domain_name_fkey', type_='foreignkey')
     with op.batch_alter_table('manager') as batch_op:
-        batch_op.drop_constraint('manager_domain_name_fkey')
-        batch_op.drop_constraint('manager_user_email_fkey')
+        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') as batch_op:
-        batch_op.drop_constraint('token_user_email_fkey')
+        batch_op.drop_constraint('token_user_email_fkey', type_='foreignkey')
     with op.batch_alter_table('fetch') as batch_op:
-        batch_op.drop_constraint('fetch_user_email_fkey')
+        batch_op.drop_constraint('fetch_user_email_fkey', type_='foreignkey')
     with op.batch_alter_table('user') as batch_op:
-        batch_op.drop_constraint('user_domain_name_fkey')
+        batch_op.drop_constraint('user_domain_name_fkey', type_='foreignkey')
 
     # lower domain names
     for domain in connection.execute(domain_table.select()):
diff --git a/core/admin/migrations/versions/9c28df23f77e_.py b/core/admin/migrations/versions/9c28df23f77e_.py
index ce712761..ba3e0098 100644
--- a/core/admin/migrations/versions/9c28df23f77e_.py
+++ b/core/admin/migrations/versions/9c28df23f77e_.py
@@ -16,13 +16,13 @@ import sqlalchemy as sa
 
 def upgrade():
     with op.batch_alter_table('user') as batch:
-        batch.alter_column('email', type_=sa.String(length=255))
+        batch.alter_column('email', type_=sa.String(length=255), nullable=False)
     with op.batch_alter_table('alias') as batch:
-        batch.alter_column('email', type_=sa.String(length=255))
+        batch.alter_column('email', type_=sa.String(length=255), nullable=False)
 
 
 def downgrade():
     with op.batch_alter_table('user') as batch:
-        batch.alter_column('email', type_=sa.String(length=255))
+        batch.alter_column('email', type_=sa.String(length=255), nullable=False)
     with op.batch_alter_table('alias') as batch:
-        batch.alter_column('email', type_=sa.String(length=255))
+        batch.alter_column('email', type_=sa.String(length=255), nullable=False)