Merge pull request #24 from thread/label-updated

Label updated times

README.md

@@ -6,7 +6,7 @@ State machines as a service.
 
 (The _master_ of _routes_ through a state machine.)
 
-Routemaster targets Python 3.6 and above.
+Routemaster targets Python 3.6 and above, and requires Postgres.
 
 
 ##### Useful Links

docs/getting_started.md

@@ -5,7 +5,8 @@
 You'll need to create a database for developing against and for running tests
 against. This can be done by running the `scripts/database/create_databases.sh`
 script. Full details of how the database, models & migrations are handled can be
-found in the [migrations docs](docs/migrations.md).
+found in the [migrations docs](docs/migrations.md). Routemaster requires
+Postgres.
 
 #### Tox
 

docs/migrations.md

@@ -1,6 +1,7 @@
 # Migrations setup
 
-Routemaster uses [`alembic`][alembic] for its migrations.
+Routemaster uses [`alembic`][alembic] for its migrations, and supports
+Postgres for its data storage.
 
 ## I need to set up my database up for the first time
 

routemaster/db/model.py

@@ -1,21 +1,47 @@
 """Database model definition."""
 import datetime
+import functools
 
+import dateutil.tz
+from sqlalchemy import Column as NullableColumn
 from sqlalchemy import (
+    DDL,
     Table,
-    Column,
     String,
     Boolean,
     Integer,
     DateTime,
     MetaData,
     ForeignKey,
+    FetchedValue,
     ForeignKeyConstraint,
+    func,
 )
 from sqlalchemy.dialects.postgresql import JSONB
 
 metadata = MetaData()
 
+Column = functools.partial(NullableColumn, nullable=False)
+
+sync_label_updated_column = DDL(
+    '''
+    CREATE OR REPLACE FUNCTION sync_label_updated_column_fn()
+        RETURNS TRIGGER AS
+            $$
+                BEGIN
+                    NEW.updated = now() AT TIME ZONE 'UTC';
+                    RETURN NEW;
+                END;
+            $$
+        LANGUAGE PLPGSQL;
+
+    CREATE TRIGGER sync_label_updated_column
+        BEFORE UPDATE ON labels
+        FOR EACH ROW
+        EXECUTE PROCEDURE sync_label_updated_column_fn();
+    ''',
+)
+
 
 """The representation of the state of a label."""
 labels = Table(
@@ -26,6 +52,15 @@
     Column('metadata', JSONB),
     Column('metadata_triggers_processed', Boolean, default=True),
     Column('deleted', Boolean, default=False),
+    Column(
+        'updated',
+        DateTime(timezone=True),
+        server_default=func.now(),
+        server_onupdate=FetchedValue(),
+    ),
+    listeners=[
+        ('after_create', sync_label_updated_column),
+    ],
 )
 
 
@@ -42,15 +77,21 @@
         ['labels.name', 'labels.state_machine'],
     ),
 
-    Column('created', DateTime, default=datetime.datetime.utcnow),
+    Column(
+        'created',
+        DateTime(timezone=True),
+        default=lambda: datetime.datetime.now(dateutil.tz.tzutc()),
+    ),
 
     # `forced = True` represents a manual transition that may not be in
     # accordance with the state machine logic.
     Column('forced', Boolean, default=False),
 
     # Null indicates starting a state machine
-    Column('old_state', String, nullable=True),
-    Column('new_state', String),
+    NullableColumn('old_state', String),
+
+    # Null indicates being deleted from a state machine
+    NullableColumn('new_state', String),
 )
 
 
@@ -92,11 +133,11 @@
 edges = Table(
     'edges',
     metadata,
-    Column('state_machine', String, primary_key=True, nullable=False),
-    Column('from_state', String, primary_key=True, nullable=False),
-    Column('to_state', String, primary_key=True, nullable=False),
-    Column('deprecated', Boolean, default=False, nullable=False),
-    Column('updated', DateTime, nullable=False),
+    Column('state_machine', String, primary_key=True),
+    Column('from_state', String, primary_key=True),
+    Column('to_state', String, primary_key=True),
+    Column('deprecated', Boolean, default=False),
+    Column('updated', DateTime),
     ForeignKeyConstraint(
         columns=('state_machine', 'from_state'),
         refcolumns=(states.c.state_machine, states.c.name),

routemaster/migrations/versions/3eb4f3b419c6_create_trigger_to_sync_updated_field.py

@@ -0,0 +1,41 @@
+"""
+create trigger to sync updated field
+
+Revision ID: 3eb4f3b419c6
+Revises: 814a6b555eb9
+"""
+import sqlalchemy as sa
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = '3eb4f3b419c6'
+down_revision = '814a6b555eb9'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.execute(
+        '''
+        CREATE OR REPLACE FUNCTION sync_label_updated_column_fn()
+            RETURNS TRIGGER AS
+                $$
+                    BEGIN
+                        NEW.updated = now() AT TIME ZONE 'UTC';
+                        RETURN NEW;
+                    END;
+                $$
+            LANGUAGE PLPGSQL;
+
+        CREATE TRIGGER sync_label_updated_column
+            BEFORE UPDATE ON labels
+            FOR EACH ROW
+            EXECUTE PROCEDURE sync_label_updated_column_fn();
+        ''',
+    )
+
+
+def downgrade():
+    op.execute('DROP TRIGGER sync_label_updated_column')
+    op.execute('DROP FUNCTION sync_label_updated_column_fn')

routemaster/migrations/versions/814a6b555eb9_make_fields_non_nullable_by_default.py

@@ -0,0 +1,150 @@
+"""
+make fields non-nullable by default
+
+Revision ID: 814a6b555eb9
+Revises: e7d5ad06c0d1
+"""
+import sqlalchemy as sa
+
+from alembic import op
+
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = '814a6b555eb9'
+down_revision = 'e7d5ad06c0d1'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.alter_column(
+        'history',
+        'label_name',
+        existing_type=sa.VARCHAR(),
+        nullable=False,
+    )
+    op.alter_column(
+        'history',
+        'label_state_machine',
+        existing_type=sa.VARCHAR(),
+        nullable=False,
+    )
+
+    def set_not_null(table, column, existing_type, server_default):
+        op.alter_column(
+            table,
+            column,
+            existing_type=existing_type,
+            server_default=server_default,
+        )
+        op.execute(
+            f"UPDATE {table} SET {column} = {server_default} "
+            f"WHERE {column} IS NULL",
+        )
+        op.alter_column(
+            table,
+            column,
+            existing_type=existing_type,
+            nullable=False,
+        )
+
+    set_not_null(
+        'history',
+        'created',
+        existing_type=postgresql.TIMESTAMP(),
+        server_default=sa.func.now(),
+    )
+    set_not_null(
+        'history',
+        'forced',
+        existing_type=sa.BOOLEAN(),
+        server_default=sa.false(),
+    )
+    set_not_null(
+        'labels',
+        'metadata',
+        existing_type=postgresql.JSONB(astext_type=sa.Text()),
+        server_default=sa.text("'{}'::json"),  # noqa
+    )
+    set_not_null(
+        'labels',
+        'metadata_triggers_processed',
+        existing_type=sa.BOOLEAN(),
+        server_default=sa.true(),
+    )
+    set_not_null(
+        'state_machines',
+        'updated',
+        existing_type=postgresql.TIMESTAMP(),
+        server_default=sa.func.now(),
+    )
+    set_not_null(
+        'states',
+        'deprecated',
+        existing_type=sa.BOOLEAN(),
+        server_default=sa.false(),
+    )
+    set_not_null(
+        'states',
+        'updated',
+        existing_type=postgresql.TIMESTAMP(),
+        server_default=sa.func.now(),
+    )
+
+
+def downgrade():
+    op.alter_column(
+        'states',
+        'updated',
+        existing_type=postgresql.TIMESTAMP(),
+        nullable=True,
+    )
+    op.alter_column(
+        'states',
+        'deprecated',
+        existing_type=sa.BOOLEAN(),
+        nullable=True,
+    )
+    op.alter_column(
+        'state_machines',
+        'updated',
+        existing_type=postgresql.TIMESTAMP(),
+        nullable=True,
+    )
+    op.alter_column(
+        'labels',
+        'metadata_triggers_processed',
+        existing_type=sa.BOOLEAN(),
+        nullable=True,
+    )
+    op.alter_column(
+        'labels',
+        'metadata',
+        existing_type=postgresql.JSONB(astext_type=sa.Text()),
+        nullable=True,
+    )
+    op.alter_column(
+        'history',
+        'label_state_machine',
+        existing_type=sa.VARCHAR(),
+        nullable=True,
+    )
+    op.alter_column(
+        'history',
+        'label_name',
+        existing_type=sa.VARCHAR(),
+        nullable=True,
+    )
+    op.alter_column(
+        'history',
+        'forced',
+        existing_type=sa.BOOLEAN(),
+        nullable=True,
+    )
+    op.alter_column(
+        'history',
+        'created',
+        existing_type=postgresql.TIMESTAMP(),
+        nullable=True,
+    )

routemaster/migrations/versions/e7d5ad06c0d1_add_updated_field_to_label.py

@@ -0,0 +1,31 @@
+"""
+add updated field to label
+
+Revision ID: e7d5ad06c0d1
+Revises: e1fec9622785
+"""
+import sqlalchemy as sa
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = 'e7d5ad06c0d1'
+down_revision = 'e1fec9622785'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.add_column(
+        'labels',
+        sa.Column(
+            'updated',
+            sa.DateTime(),
+            nullable=False,
+            server_default=sa.func.now(),
+        ),
+    )
+
+
+def downgrade():
+    op.drop_column('labels', 'updated')

routemaster/state_machine/tests/test_state_machine.py

@@ -236,3 +236,39 @@ def test_metadata_update_gate_evaluations_dont_race_processing_subsequent_metada
     assert_history([
         (None, 'gate_1'),
     ])
+
+
+def test_maintains_updated_field_on_label(app_config, mock_test_feed):
+    label = LabelRef('foo', 'test_machine')
+
+    with mock_test_feed():
+        state_machine.create_label(
+            app_config,
+            label,
+            {},
+        )
+
+    with app_config.db.begin() as conn:
+        first_updated = conn.scalar(
+            select([labels.c.updated]).where(and_(
+                labels.c.name == label.name,
+                labels.c.state_machine == label.state_machine,
+            )),
+        )
+
+    with mock_test_feed():
+        state_machine.update_metadata_for_label(
+            app_config,
+            label,
+            {'foo': 'bar'},
+        )
+
+    with app_config.db.begin() as conn:
+        second_updated = conn.scalar(
+            select([labels.c.updated]).where(and_(
+                labels.c.name == label.name,
+                labels.c.state_machine == label.state_machine,
+            )),
+        )
+
+    assert second_updated > first_updated