How to use the installer.constants function in installer

def prepare_postgres(self):
        dirname = "postgres"
        self.client.volumes.create(constants.POSTGRES_DB_VOLUME, labels={"carrier": "postgres"})
        self.volumes_piece += f"\n  {constants.POSTGRES_DB_VOLUME}:\n    external: true"
        makedirs(path.join(constants.WORKDIR, dirname), exist_ok=True)
        with open(path.join(constants.WORKDIR, dirname, "Dockerfile"), "w") as f:
            f.write(constants.POSTGRESFILE)
        with open(path.join(constants.WORKDIR, dirname, constants.POSTGRES_ENTRYPOINT_FILENAME), "w") as f:
            f.write(constants.POSTGRES_ENTRYPOINT)
        self.postgres_piece = constants.POSTGRES_COMPOSE.format(
            path=path.join(constants.WORKDIR, dirname),
            volume=constants.POSTGRES_DB_VOLUME
        )

def prepare_influx(self):
        self.client.volumes.create(constants.INFLUX_VOLUME_NAME, labels={"carrier": "influx"})
        self.volumes_piece += f'\n  {constants.INFLUX_VOLUME_NAME}:\n    external: true'
        makedirs(path.join(constants.WORKDIR, 'influx'), exist_ok=True)
        with open(path.join(constants.WORKDIR, 'influx', "Dockerfile"), "w") as f:
            f.write(constants.INFLUXFILE)
        with open(path.join(constants.WORKDIR, 'influx', "influxdb.conf"), "w") as f:
            f.write(constants.INFLUX_CONF)
        self.influx_piece = constants.INFLUX_COMPOSE.format(path=path.join(constants.WORKDIR, 'influx'),
                                                            volume=constants.INFLUX_VOLUME_NAME)

def seed_grafana_dashboards(self):
        self._seed_data_to_influx(constants.GRAFANA_URL.format(host=self.data['dns']), constants.GRAFANA_DASHBOARDS)

def prepare_postgres(self):
        dirname = "postgres"
        self.client.volumes.create(constants.POSTGRES_DB_VOLUME, labels={"carrier": "postgres"})
        self.volumes_piece += f"\n  {constants.POSTGRES_DB_VOLUME}:\n    external: true"
        makedirs(path.join(constants.WORKDIR, dirname), exist_ok=True)
        with open(path.join(constants.WORKDIR, dirname, "Dockerfile"), "w") as f:
            f.write(constants.POSTGRESFILE)
        with open(path.join(constants.WORKDIR, dirname, constants.POSTGRES_ENTRYPOINT_FILENAME), "w") as f:
            f.write(constants.POSTGRES_ENTRYPOINT)
        self.postgres_piece = constants.POSTGRES_COMPOSE.format(
            path=path.join(constants.WORKDIR, dirname),
            volume=constants.POSTGRES_DB_VOLUME
        )

def prepare_influx(self):
        self.client.volumes.create(constants.INFLUX_VOLUME_NAME, labels={"carrier": "influx"})
        self.volumes_piece += f'\n  {constants.INFLUX_VOLUME_NAME}:\n    external: true'
        makedirs(path.join(constants.WORKDIR, 'influx'), exist_ok=True)
        with open(path.join(constants.WORKDIR, 'influx', "Dockerfile"), "w") as f:
            f.write(constants.INFLUXFILE)
        with open(path.join(constants.WORKDIR, 'influx', "influxdb.conf"), "w") as f:
            f.write(constants.INFLUX_CONF)
        self.influx_piece = constants.INFLUX_COMPOSE.format(path=path.join(constants.WORKDIR, 'influx'),
                                                            volume=constants.INFLUX_VOLUME_NAME)

def prepare_grafana(self):
        self.client.volumes.create(constants.GRAFANA_VOLUME_NAME, labels={"carrier": "grafana"})
        self.volumes_piece += f'\n  {constants.GRAFANA_VOLUME_NAME}:\n    external: true'
        makedirs(path.join(constants.WORKDIR, 'grafana'), exist_ok=True)
        self.grafana_piece = constants.GRAFANA_COMPOSE.format(volume=constants.GRAFANA_VOLUME_NAME,
                                                              password=self.data['grafana_password'],
                                                              host=self.data['dns'])

def seed_influx_dbs(self):
        self._seed_data_to_influx(constants.DATASOURCES_HOST.format(host=self.data['dns']), constants.DATASOURCES)

def prepare_postgres(self):
        dirname = "postgres"
        self.client.volumes.create(constants.POSTGRES_DB_VOLUME, labels={"carrier": "postgres"})
        self.volumes_piece += f"\n  {constants.POSTGRES_DB_VOLUME}:\n    external: true"
        makedirs(path.join(constants.WORKDIR, dirname), exist_ok=True)
        with open(path.join(constants.WORKDIR, dirname, "Dockerfile"), "w") as f:
            f.write(constants.POSTGRESFILE)
        with open(path.join(constants.WORKDIR, dirname, constants.POSTGRES_ENTRYPOINT_FILENAME), "w") as f:
            f.write(constants.POSTGRES_ENTRYPOINT)
        self.postgres_piece = constants.POSTGRES_COMPOSE.format(
            path=path.join(constants.WORKDIR, dirname),
            volume=constants.POSTGRES_DB_VOLUME
        )

def prepare_influx(self):
        self.client.volumes.create(constants.INFLUX_VOLUME_NAME, labels={"carrier": "influx"})
        self.volumes_piece += f'\n  {constants.INFLUX_VOLUME_NAME}:\n    external: true'
        makedirs(path.join(constants.WORKDIR, 'influx'), exist_ok=True)
        with open(path.join(constants.WORKDIR, 'influx', "Dockerfile"), "w") as f:
            f.write(constants.INFLUXFILE)
        with open(path.join(constants.WORKDIR, 'influx', "influxdb.conf"), "w") as f:
            f.write(constants.INFLUX_CONF)
        self.influx_piece = constants.INFLUX_COMPOSE.format(path=path.join(constants.WORKDIR, 'influx'),
                                                            volume=constants.INFLUX_VOLUME_NAME)

def create_databases(self):
        influx_container = self.client.containers.list(filters={"label": "carrier=influx"})[0]
        for db in constants.INFLUX_DATABASES:
            influx_container.exec_run(constants.INFLUX_CREATEDB_COMMAND.format(db=db))