I am using Flask SQLalchemy in my google app engine standard environment project to try and connect to my GCP Postgresql database..
According to google docs, the url can be created in this format
# postgres+pg8000://<db_user>:<db_pass>#/<db_name>?unix_socket=/cloudsql/<cloud_sql_instance_name>
and below is my code
from flask import Flask, request, jsonify
import constants
app = Flask(__name__)
# Database configuration from GCP postgres+pg8000
DB_URL = 'postgres+pg8000://{user}:{pw}#/{db}?unix_socket=/cloudsql/{instance_name}'.format(user=user,pw=password,db=dbname, instance_name=instance_name)
app.config['SQLALCHEMY_DATABASE_URI'] = DB_URL
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False # silence the
deprecation warning
sqldb = SQLAlchemy(app)
This is the error i keep getting:
File "/env/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 412, in connect return self.dbapi.connect(*cargs, **cparams) TypeError: connect() got an unexpected keyword argument 'unix_socket'
The argument to specify a unix socket varies depending on what driver you use. According to the pg8000 docs, you need to use unix_sock instead of unix_socket.
To see this in the context of an application, you can take a look at this sample application.
It's been more than 1.5 years and no one has posted the solution yet :)
Anyway, just use the below URI
postgres+psycopg2://<db_user>:<db_pass>#<public_ip>/<db_name>?host=/cloudsql/<cloud_sql_instance_name>
And yes, don't forget to add your systems public IP address to the authorized network.
Example of docs
As you can read in the gcloud guides, an examplary connection string is
postgres+pg8000://<db_user>:<db_pass>#/<db_name>?unix_sock=<socket_path>/<cloud_sql_instance_name>/.s.PGSQL.5432
Varying engine and socket part
Be aware that the engine part postgres+pg8000 varies depending on your database and used driver. Also, depending on your database client library, the socket part ?unix_sock=<socket_path>/<cloud_sql_instance_name>/.s.PGSQL.5432 may be needed or can be omitted, as per:
Note: The PostgreSQL standard requires a .s.PGSQL.5432 suffix in the socket path. Some libraries apply this suffix automatically, but others require you to specify the socket path as follows: /cloudsql/INSTANCE_CONNECTION_NAME/.s.PGSQL.5432.
PostgreSQL and flask_sqlalchemy
For instance, I am using PostgreSQL with flask_sqlalchemy as database client and pg8000 as driver and my working connection string is only postgres+pg8000://<db_user>:<db_pass>#/<db_name>.
Related
I have problem connecting to MongoDb using pymongo driver (Python 3.10, pymongo 4.2.0, MongoDb 6), specifically, authentication steps fails. Please see below my code:
import pymongo
from pymongo import MongoClient
client=MongoClient('mongodb://10.10.1.8:27017')
client.admin.authenticate('dev01','my_password_here')
I am behind company firewall, that's why you see internal IP address - 10.10.1.8
When I try to test run Python code to store data, I am getting the following error:
File "C:\Users\ABC\Documents\python_development\pymongo_test.py", line 7, in <module>
client.admin.authenticate('dev01','my_password_here')
File "C:\Users\ABC\AppData\Local\Programs\Python\Python310\lib\site-packages\pymongo\collection.py", line 3194,
in __call__ raise TypeError(
TypeError: 'Collection' object is not callable. If you meant to call the 'authenticate' method
on a 'Database' object it is failing because no such method exists.
MongoDb sits on virtual Linux Ubuntu server that sits on top of Linux Debian server. My laptop has Windows 10.
The code looks correct, any ideas why this is happening?
Migration guide from pymongo 3.x to 4.x
https://pymongo.readthedocs.io/en/stable/migrate-to-pymongo4.html?highlight=authenticate#database-authenticate-and-database-logout-are-removed reads:
Removed pymongo.database.Database.authenticate() and pymongo.database.Database.logout(). Authenticating multiple users on the same client conflicts with support for logical sessions in MongoDB 3.6+. To authenticate as multiple users, create multiple instances of MongoClient. Code like this:
client = MongoClient()
client.admin.authenticate('user1', 'pass1')
client.admin.authenticate('user2', 'pass2')
can be changed to this:
client1 = MongoClient(username='user1', password='pass1')
client2 = MongoClient(username='user2', password='pass2')
I have a fast API application. Initially, I was passing my DB URI via ngrok tunnel like this in my SAM template. In this setup Lambda will be using my local machine's PSQL DB.
DbConnnectionString:
Type: String
Default: postgresql://<uname>:<pwd>#x.tcp.ngrok.io:PORT/DB
This is how I read the URI in my Python code
# config.py
DATABASE_URL = os.environ.get('DB_URI')
db_engine = create_engine(DATABASE_URL)
db_session = sessionmaker(autocommit=False, autoflush=False,bind=db_engine)
print(f"Configs initialized for {API_V1_STR}")
# app.py
# 3rd party
from fastapi import FastAPI
# Custom
from config.app_config import PROJECT_NAME, db_engine
from models.db_models import Base
print("Creating all database")
Base.metadata.create_all(bind=db_engine)
app = FastAPI(title=PROJECT_NAME)
print("APP created")
In this setup, everything seems to work as expected.
But whenever I replace the DB URL with RDS DB, suddenly the call gets stuck at create all database step as shown in the image below. when this happens the lambda always times out and throws exceptions.
If I run the code locally using uvicorn this error doesn't occur.
Everything works as expected.
When I use sam local invoke even with RDS URL, the API call works without any issues.
This problem occurs only while deployed in AWS Lambda.
I notice that configs are initialized twice in this setup, Once before START request ID and once after.
I have tried reading up on it but not clear what could I do to fix this. Any help would be much appreciated.
It was my bad!. I didn't pay attention to security groups. It was a connection timeout all along. Once I fixed the port access in Security groups, lambda started working as expected.
I have a MongoDB instance running on Kubernetes and I'm trying to connect to it using Python with the Kubernetes library.
I'm connecting to the context on cmd line using:
kubectl config use-context CONTEXTNAME
With Python, I'm using:
from kubernetes import client, config
config.load_kube_config(
context = 'CONTEXTNAME'
)
To connect to MongoDB in cmd line:
kubectl port-forward svc/mongo-mongodb 27083:27017 -n production &
I then open a new terminal and use PORT_FORWARD_PID=$! to connect
I'm trying to get connect to the MongoDB instance using Python with the Kubernetes-client library, any ideas as to how to accomplish the above?
Define a kubernetes service for example like this, and then reference your mongodb using a connection string similar to mongodb://<service-name>.default.svc.cluster.local
My understanding is that you need to find out your DB Client Endpoint.
That could be achieved if you follow this article MongoDB on K8s
make sure you got the URI for MongoDB.
(example)
“mongodb://mongo-0.mongo,mongo-1.mongo,mongo-2.mongo:27017/dbname\_?”
and after that, you can call your DB client in Python script.
import pymongo
import sys
##Create a MongoDB client
client = pymongo.MongoClient('mongodb://......')
##Specify the database to be used
db = client.test
##Specify the collection to be used
col = db.myTestCollection
##Insert a single document
col.insert_one({'hello':'world'})
##Find the document that was previously written
x = col.find_one({'hello':'world'})
##Print the result to the screen
print(x)
##Close the connection
client.close()
Hope that will give you an idea.
Good luck!
I am pretty much new to this concept.
Currently, I am connecting to oracle database directly using the credentials within a python script but I want to store the connection string in a text file or a separate .py file and call them as I use the same credentials for multiple scripts.
I am using cx_oracle and sqlalchemy packages to connect to two databases as I extract data from the source and push it to the target(both the source and target are oracle databases).
import cx_Oracle
from sqlalchemy import create_engine, types
dsn_tns = cx_Oracle.makedsn('shost', 'sport', service_name='sservice_name')
conn = cx_Oracle.connect(user='suser', password='spw', dsn = dsn_tns)
engine = create_engine('oracle://tuser:tpw#thost:tport/tservice_name')
I'd really want to automate this process as I reuse the same connection string in multiple scripts and I'd really appreciate if I can get some help.
I am using HAProxy to for AWS RDS (MySQL) load balancing for my app, that is written using Flask.
The HAProxy.cfg file has following configuration for the DB
listen mysql
bind 127.0.0.1:3306
mode tcp
balance roundrobin
option mysql-check user haproxy_check
option log-health-checks
server db01 MASTER_DATABSE_ENDPOINT.rds.amazonaws.com
server db02 READ_REPLICA_ENDPOINT.rds.amazonaws.com
I am using SQLALCHEMY and it's URI is:
SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://USER:PASSWORD#127.0.0.1:3306/DATABASE'
but when I am running an API in my test environment, the APIs that are just reading stuff from DB are executing just fine but the APIs that are writing something to DB are giving me errors mostly that:
(pymysql.err.InternalError) (1290, 'The MySQL server is running with the --read-only option so it cannot execute this statement')
I think I need to use 2 URLs now in this scenario, one for read-only operation and one for writes.
How does this work with Flask and SQLALCHEMY with HAProxy?
How do I tell my APP to use one URL for write operations and other HAProxy URL to read-only operations?
I didn't find any help from the documentation of SQLAlchemy.
Binds
Flask-SQLAlchemy can easily connect to multiple databases. To achieve
that it preconfigures SQLAlchemy to support multiple “binds”.
SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://USER:PASSWORD#DEFAULT:3306/DATABASE'
SQLALCHEMY_BINDS = {
'master': 'mysql+pymysql://USER:PASSWORD#MASTER_DATABSE_ENDPOINT:3306/DATABASE',
'read': 'mysql+pymysql://USER:PASSWORD#READ_REPLICA_ENDPOINT:3306/DATABASE'
}
Referring to Binds:
db.create_all(bind='read') # from read only
db.create_all(bind='master') # from master