问在连接到SQL云的app-engine中部署简单应用程序时出现错误

EN

runtime: python27
api_version: 1
threadsafe: yes
service: practica

handlers:
- url: /
  script: main.app

libraries:
- name: MySQLdb
  version: "latest"

# [START gae_python_mysql_env]
env_variables:
    CLOUDSQL_CONNECTION_NAME: practica-final-297818:europe-west3:practica-sql
    CLOUDSQL_USER: root
    CLOUDSQL_PASSWORD: 123456
# [END gae_python_mysql_env]

ispatch()
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/dd89b7af809b5e76/python27/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 547, in dispatch
    return self.handle_exception(e, self.app.debug)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/dd89b7af809b5e76/python27/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 545, in dispatch
    return method(*args, **kwargs)
  File "/base/data/home/apps/h~practica-final-297818/practica:version-1-0-0.431541023169113748/main.py", line 66, in get
    db = connect_to_cloudsql()
  File "/base/data/home/apps/h~practica-final-297818/practica:version-1-0-0.431541023169113748/main.py", line 46, in connect_to_cloudsql
    passwd=CLOUDSQL_PASSWORD)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/dd89b7af809b5e76/python27/python27_lib/versions/third_party/MySQLdb-1.2.5/MySQLdb/__init__.py", line 81, in Connect
    return Connection(*args, **kwargs)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/dd89b7af809b5e76/python27/python27_lib/versions/third_party/MySQLdb-1.2.5/MySQLdb/connections.py", line 193, in __init__
    super(Connection, self).__init__(*args, **kwargs2)
OperationalError: (2062, 'Cloud SQL socket open failed with error: No such file or directory')

settings:
  activationPolicy: ALWAYS
  availabilityType: REGIONAL
  backupConfiguration:
    backupRetentionSettings:
      retainedBackups: 7
      retentionUnit: COUNT
    binaryLogEnabled: true
    enabled: true
    kind: sql#backupConfiguration
    location: eu
    startTime: 11:00
    transactionLogRetentionDays: 7
  dataDiskSizeGb: '100'
  dataDiskType: PD_SSD
  ipConfiguration:
    authorizedNetworks:
    - kind: sql#aclEntry
      name: practica
      value: 111.111.111.111
    ipv4Enabled: true
  kind: sql#settings
  locationPreference:
    kind: sql#locationPreference
    zone: europe-west3-b
  maintenanceWindow:
    day: 0
    hour: 0
    kind: sql#maintenanceWindow
  pricingPlan: PER_USE
  settingsVersion: '25'
  storageAutoResize: true
  storageAutoResizeLimit: '0'
  tier: db-f1-micro
state: RUNNABLE