Add Alembic to project for database migrations

migrations/env.py

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+from logging.config import fileConfig
+
+from alembic import context
+
+from tofu_api.app import create_app
+from tofu_api.models import BaseModel
+
+# This is the Alembic Config object, which provides access to the values within the .ini file in use.
+alembic_config = context.config
+
+# Interpret the config file for Python logging. This line sets up loggers basically.
+if alembic_config.config_file_name is not None:
+    fileConfig(alembic_config.config_file_name)
+
+# Create Flask app, which loads the app config and initializes the database engine.
+app = create_app()
+db = app.dependencies.get_sqlalchemy()
+
+
+def process_revision_directives(_context, _revision, directives):
+    """
+    Callback used to prevent generating empty migrations with autogenerate.
+    Source: https://alembic.sqlalchemy.org/en/latest/cookbook.html#don-t-generate-empty-migrations-with-autogenerate
+    """
+    if alembic_config.cmd_opts.autogenerate and directives[0].upgrade_ops.is_empty():
+        directives[:] = []
+
+
+def run_migrations_offline():
+    """
+    Run migrations in 'offline' mode, which does not require an actual database engine and can be used to generate SQL scripts.
+    """
+    context.configure(
+        url=app.config.sqlalchemy_database_uri,
+        target_metadata=BaseModel.metadata,
+        process_revision_directives=process_revision_directives,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online():
+    """
+    Run migrations in 'online' mode, which requires a database engine.
+    """
+    with db.engine.connect() as connection:
+        context.configure(
+            connection=connection,
+            target_metadata=BaseModel.metadata,
+            process_revision_directives=process_revision_directives,
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/script.py.mako

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+"""
+${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+"""
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# Revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/2022_04_15_1605-716726b4a1fe_initial_revision.py

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+"""
+Initial revision
+
+Revision ID: 716726b4a1fe
+Revises: 
+Create Date: 2022-04-15 16:05:29.358429+02:00
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# Revision identifiers, used by Alembic.
+revision = '716726b4a1fe'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table(
+        'tasks',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(length=255), nullable=False),
+        sa.Column('description', sa.Text(), nullable=False),
+        sa.PrimaryKeyConstraint('id', name=op.f('pk_tasks'))
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('tasks')
+    # ### end Alembic commands ###