Connecting to PostgreSQL on Google Cloud Platform using Unix Sockets and SQLAlchemy

Question

I am trying to connect to a PostgreSQL database hosted on a Google Cloud Platform instance using unix sockets and the SQLAlchemy library. My database instance is configured to accept unix socket connections.

When I run my application locally, I use the following line to connect to the database and it works perfectly:

pool = create_engine("postgresql://{user}:{password}@/{dbname}?host={socket}".format(params_dic))

However, when I run the same application on Google Cloud Platform, I get an error with the following connection string:

pool = create_engine(engine.url.URL.create(
    drivername="postgresql+psycopg2",
    username=params_dic['user'],
    password=params_dic['password'],
    database=params_dic['dbname'], 
    query={"unix_socket": "{}/.s.PGSQL.5432".format(params_dic['socket'])},
    ),
pool_size=5,
max_overflow=2,
pool_timeout=30,
pool_recycle=100,)

The error message is: (psycopg2.ProgrammingError) invalid dsn: invalid connection option "unix_socket"

How can I connect to a PostgreSQL database on Google Cloud Platform using unix sockets and SQLAlchemy?

I Tried connecting to GCP Postgres with unix socket and SQLAlchemy, expected success but got error "invalid dsn: invalid connection option "unix_socket"

Also I dont want to use a Public IP conection.

Answer 1

I was able to solve it using the psycopg2 library directly, there was also a missing line in the .yaml file to add the instance to the uinx socket. Thank you all.

de function:

def connect(params_dic):
    """ 
    Generate the connection to the database
    """
    if is_gcp():
        print('coneccting from GCP...')
        conn = None
        try:
            conn = ppg2.connect(
                host=params_dic['socket_dir']+'/'+params_dic['socket'],
                database = params_dic['dbname'],
                user = params_dic['user'],
                password = params_dic['password'],
                )
            return conn
        except Exception as error:
            print('problema en la funcion ppg2: ',error)
    else:
        print("Running locally")
        conn = None
        try:
            # connect to the PostgreSQL server
            conn = ppg2.connect(**params_dic)
        except (Exception, ppg2.DatabaseError) as error:
            print(error)
        return conn

the missing line in the yaml file

beta_settings:
    cloud_sql_instances: proyect-name:region:instance-name