import datetime from sqlalchemy import Column, VARCHAR, CHAR, ForeignKey, DATETIME, update, and_, inspect from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.engine import Engine from sqlalchemy.orm import sessionmaker Base = declarative_base() class Origin(Base): __tablename__ = "origin" origin_ref = Column(CHAR(length=36), primary_key=True, unique=True, index=True) # uuid4 # service_instance_xid = Column(CHAR(length=36), nullable=False, index=True) # uuid4 # not necessary, we only support one service_instance_xid ('INSTANCE_REF') hostname = Column(VARCHAR(length=256), nullable=True) guest_driver_version = Column(VARCHAR(length=10), nullable=True) os_platform = Column(VARCHAR(length=256), nullable=True) os_version = Column(VARCHAR(length=256), nullable=True) def __repr__(self): return f'Origin(origin_ref={self.origin_ref}, hostname={self.hostname})' def serialize(self) -> dict: return { 'origin_ref': self.origin_ref, # 'service_instance_xid': self.service_instance_xid, 'hostname': self.hostname, 'guest_driver_version': self.guest_driver_version, 'os_platform': self.os_platform, 'os_version': self.os_version, } @staticmethod def create_statement(engine: Engine): from sqlalchemy.schema import CreateTable return CreateTable(Origin.__table__).compile(engine) @staticmethod def create_or_update(engine: Engine, origin: "Origin"): session = sessionmaker(bind=engine)() entity = session.query(Origin).filter(Origin.origin_ref == origin.origin_ref).first() if entity is None: session.add(origin) else: x = dict( hostname=origin.hostname, guest_driver_version=origin.guest_driver_version, os_platform=origin.os_platform, os_version=origin.os_version ) session.execute(update(Origin).where(Origin.origin_ref == origin.origin_ref).values(**x)) session.commit() session.flush() session.close() @staticmethod def delete(engine: Engine, origins: ["Origin"] = None) -> int: session = sessionmaker(bind=engine)() if origins is None: deletions = session.query(Origin).delete() else: deletions = session.query(Origin).filter(Origin.origin_ref in origins).delete() session.commit() session.close() return deletions class Lease(Base): __tablename__ = "lease" lease_ref = Column(CHAR(length=36), primary_key=True, nullable=False, index=True) # uuid4 origin_ref = Column(CHAR(length=36), ForeignKey(Origin.origin_ref, ondelete='CASCADE'), nullable=False, index=True) # uuid4 # scope_ref = Column(CHAR(length=36), nullable=False, index=True) # uuid4 # not necessary, we only support one scope_ref ('ALLOTMENT_REF') lease_created = Column(DATETIME(), nullable=False) lease_expires = Column(DATETIME(), nullable=False) lease_updated = Column(DATETIME(), nullable=False) def __repr__(self): return f'Lease(origin_ref={self.origin_ref}, lease_ref={self.lease_ref}, expires={self.lease_expires})' def serialize(self, renewal_period: float, renewal_delta: datetime.timedelta) -> dict: return { 'lease_ref': self.lease_ref, 'origin_ref': self.origin_ref, # 'scope_ref': self.scope_ref, 'lease_created': self.lease_created.isoformat(), 'lease_expires': self.lease_expires.isoformat(), 'lease_updated': self.lease_updated.isoformat(), 'lease_renewal': Lease.calculate_renewal(renewal_period, renewal_delta), } @staticmethod def create_statement(engine: Engine): from sqlalchemy.schema import CreateTable return CreateTable(Lease.__table__).compile(engine) @staticmethod def create_or_update(engine: Engine, lease: "Lease"): session = sessionmaker(bind=engine)() entity = session.query(Lease).filter(Lease.lease_ref == lease.lease_ref).first() if entity is None: if lease.lease_updated is None: lease.lease_updated = lease.lease_created session.add(lease) else: x = dict(origin_ref=lease.origin_ref, lease_expires=lease.lease_expires, lease_updated=lease.lease_updated) session.execute(update(Lease).where(Lease.lease_ref == lease.lease_ref).values(**x)) session.commit() session.flush() session.close() @staticmethod def find_by_origin_ref(engine: Engine, origin_ref: str) -> ["Lease"]: session = sessionmaker(bind=engine)() entities = session.query(Lease).filter(Lease.origin_ref == origin_ref).all() session.close() return entities @staticmethod def find_by_lease_ref(engine: Engine, lease_ref: str) -> "Lease": session = sessionmaker(bind=engine)() entity = session.query(Lease).filter(Lease.lease_ref == lease_ref).first() session.close() return entity @staticmethod def find_by_origin_ref_and_lease_ref(engine: Engine, origin_ref: str, lease_ref: str) -> "Lease": session = sessionmaker(bind=engine)() entity = session.query(Lease).filter(and_(Lease.origin_ref == origin_ref, Lease.lease_ref == lease_ref)).first() session.close() return entity @staticmethod def renew(engine: Engine, lease: "Lease", lease_expires: datetime.datetime, lease_updated: datetime.datetime): session = sessionmaker(bind=engine)() x = dict(lease_expires=lease_expires, lease_updated=lease_updated) session.execute(update(Lease).where(and_(Lease.origin_ref == lease.origin_ref, Lease.lease_ref == lease.lease_ref)).values(**x)) session.commit() session.close() @staticmethod def cleanup(engine: Engine, origin_ref: str) -> int: session = sessionmaker(bind=engine)() deletions = session.query(Lease).filter(Lease.origin_ref == origin_ref).delete() session.commit() session.close() return deletions @staticmethod def delete(engine: Engine, lease_ref: str) -> int: session = sessionmaker(bind=engine)() deletions = session.query(Lease).filter(Lease.lease_ref == lease_ref).delete() session.commit() session.close() return deletions @staticmethod def calculate_renewal(renewal_period: float, delta: datetime.timedelta): """ LEASE_RENEWAL_PERIOD=0.2 # 20% delta = datetime.timedelta(days=1) renew = delta.total_seconds() * LEASE_RENEWAL_PERIOD renew = timedelta(seconds=renew) expires = delta - renew # 19.2 """ renew = delta.total_seconds() * renewal_period renew = datetime.timedelta(seconds=renew) return delta - renew def init(engine: Engine): tables = [Origin, Lease] db = inspect(engine) session = sessionmaker(bind=engine)() for table in tables: if not db.dialect.has_table(engine.connect(), table.__tablename__): session.execute(str(table.create_statement(engine))) session.commit() session.close() def migrate(engine: Engine): db = inspect(engine) def upgrade_1_0_to_1_1(): x = db.dialect.get_columns(engine.connect(), Lease.__tablename__) x = next(_ for _ in x if _['name'] == 'origin_ref') if x['primary_key'] > 0: print('Found old database schema with "origin_ref" as primary-key in "lease" table. Dropping table!') print(' Your leases are recreated on next renewal!') print(' If an error message appears on the client, you can ignore it.') Lease.__table__.drop(bind=engine) init(engine) # def upgrade_1_2_to_1_3(): # x = db.dialect.get_columns(engine.connect(), Lease.__tablename__) # x = next((_ for _ in x if _['name'] == 'scope_ref'), None) # if x is None: # Lease.scope_ref.compile() # column_name = Lease.scope_ref.name # column_type = Lease.scope_ref.type.compile(engine.dialect) # engine.execute(f'ALTER TABLE "{Lease.__tablename__}" ADD COLUMN "{column_name}" {column_type}') upgrade_1_0_to_1_1() # upgrade_1_2_to_1_3()