I wrote a simple lambda function in python to fetch some data from AWS RDS. PostgreSQL is the database engines.
conn = psycopg2.connect(host=hostname, user=username, password=password, dbname=db_name, connect_timeout=50)
I did like this. But it didn't work. Always returns an error like this
Response:
{
"errorMessage": "2018-06-06T11:28:53.775Z Task timed out after 3.00 seconds"
}
How can I resolve this??
It is most probably timing-out because the network connection cannot be established.
If you wish to connect to the database via a public IP address, then your Lambda function should not be connected to the VPC. Instead, the connection will go from Lambda, via the internet, into the VPC and to the Amazon RDS instance.
If you wish to connect to the database via a private IP address, then your Lambda function should be configured to use the same VPC as the Amazon RDS instance.
In both cases, the connection should be established using the DNS Name of the RDS instance, but it will resolve differently inside and outside of the VPC.
Finally, the Security Group associated with the Amazon RDS instance needs to allow the incoming connection. This, too, will vary depending upon whether the request is coming from public or private space. You can test by opening the security group to 0.0.0.0/0 and, if it works, then try to restrict it to the minimum possible range.
Related
Hello fellow AWS contributors, I’m currently working on a project to set up an example of connecting a Lambda function to our PostgreSQL database hosted on RDS. I tested my Python + SQL code locally (in VS code and DBeaver) and it works perfectly fine with including only basic credentials(host, dbname, username password). However, when I paste the code in Lambda function, it gave me all sorts of errors. I followed this template and modified my code to retrieve the credentials from secret manager instead.
I’m currently using boto3, psycopg2, and secret manager to get credentials and connect to the database.
List of errors I’m getting-
server closed the connection unexpectedly. This probably means the server terminated abnormally before or while processing the request
could not connect to server: Connection timed out. Is the server running on host “db endpoint” and accepting TCP/IP connections on port 5432?
FATAL: no pg_hba.conf entry for host “ip:xxx”, user "userXXX", database "dbXXX", SSL off
Things I tried -
RDS and Lambda are in the same VPC, same subnet, same security group.
IP address is included in the inbound rule
Lambda function is set to run up to 15 min, and it always stops before it even hits 15 min
I tried both database endpoint and database proxy endpoint, none of it works.
It doesn’t really make sense to me that when I run the code locally, I only need to provide the host, dbname, username, and password, that’s it, and I’m able to write all the queries and function I want. But when I throw the code in lambda function, it’s requiring all these secret manager, VPC security group, SSL, proxy, TCP/IP rules etc. Can someone explain why there is a requirement difference between running it locally and on lambda?
Finally, does anyone know what could be wrong in my setup? I'm happy to provide any information in related to this, any general direction to look into would be really helpful. Thanks!
Following the directions at the link below to build a specific psycopg2 package and also verifying the VPC subnets and security groups were configured correctly solved this issue for me.
I built a package for PostgreSQL 10.20 using psycopg2 v2.9.3 for Python 3.7.10 running on an Amazon Linux 2 AMI instance. The only change to the directions I had to make was to put the psycopg2 directory inside a python directory (i.e. "python/psycopg2/") before zipping it -- the import psycopg2 statement in the Lambda function failed until I did that.
https://kalyanv.com/2019/06/10/using-postgresql-with-python-on-aws-lambda.html
This the VPC scenario I'm using. The Lambda function is executing inside the Public Subnet and associated Security Group. Inbound rules for the Private Subnet Security Group only allow TCP connections to 5432 for the Public Subnet Security Group.
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_VPC.Scenarios.html#USER_VPC.Scenario1
I am trying to connect to a MySQL server through ssh tunnel on one of my google cloud functions. This works fine in my home environment. I assume it is some port issue on cloud function.
Edit: For clarification the MySQL server sits on a Namecheap shared hosting web server. Not Google Cloud SQL
Every time I run this I timeout with "unknown error". The tunnel appears to be successful. I am however unable to get the mysql connection to work.
import base64
import sshtunnel
import mysql.connector
def testing(event, context):
"""
Testing function
"""
with sshtunnel.SSHTunnelForwarder(
("server address", port),
ssh_username="user",
ssh_password="password",
remote_bind_address=("127.0.0.1",3306),
) as server:
print(server.local_bind_port)
with mysql.connector.connect(
user="user",
password="password",
host="localhost",
database="database",
port=server.local_bind_port
) as connection:
print(connection)
There's too many steps to list, but I'm wondering if the "connector" setup plays a difference even for SSH. Maybe you have to create a connector as shown here (notice how the instructions in "Private IP" tab are different than on your local computer). Then, configure Cloud Functions to use that connector. Make sure you also use the right port.
A Serverless VPC Access connector handles communication to your VPC
network. To connect directly with private IP, you need to:
Make sure that the Cloud SQL instance created above has a private IP
address. If you need to add one, see the Configuring private IP page
for instructions.
Create a Serverless VPC Access connector in the same
VPC network as your Cloud SQL instance. Unless you're using Shared
VPC, a connector must be in the same project and region as the
resource that uses it, but the connector can send traffic to resources
in different regions. Serverless VPC Access supports communication to VPC networks connected via Cloud VPN and VPC Network Peering. Serverless VPC Access does not support legacy networks.
Configure Cloud Functions to use the connector.
Connect using your
instance's private IP and port 3306.
Keep in mind, this "unknown" error could also very well be due to the Cloud SQL Admin API not being enabled here. As a matter of fact, make sure you follow that entire page as it's a broad question.
Let us know what worked for this type of error.
I am using a PostgreSQL in Cloud SQL along with psycopg2 library to connect to database from my python code. The current one that I have is associated with a VPC network in which my google compute engines also in that VPC. So, in this case, my config to connect to this cloud sql instance can use private ip and my config look like this:
config['db-cloudsql'] = {
"host" : "10.x.x.x" # cloud sql private ip address
"user" : "postgres"
"password" :"xxxxx"
"database" : "postgres"
}
But now I have another vm instance from another VPC network that need to access to this cloud sql instance. I know that I can access to the cloud sql instance using public ip. (by adding my vm to authorised network) But this vm need to access to the cloud sql instance very often. So I am not sure that the cost from accessing with public ip will be higher compared with accessing with private ip (cannot find any related document about this). I tried peering 2 vpc networks for accessing with private ip but just found that I cannot use this method to connect to sql with private ip from this document
I have found from the document that I can use instance connection name as a host for my config so it should be something like:
config['db-cloudsql'] = {
"host" : "project-name:asia-southeast1:mydbname" #instance connection name
"user" : "postgres"
"password" :"xxxxx"
"database" : "postgres"
}
I haven't try this method yet, it might not working but if it somehow works, how will it differ from using public ip addess in term of cost?
Thank you
It seems like your question boils down into two parts:
Are there any alternatives to public IP or private IP?
No. You have to use one or the other to connect to your Cloud SQL instance. Private IP allows access from a VPC, Public IP is used pretty much everywhere else.
Cost of public IP vs private IP
You can find a breakdown of the costs here. In short, there is not really any extra charges with a Public IP. You do have to pay $.01 per hour while the instance is idle (to reserve the public IP address), and just like private IPs, you are responsible for costs of the Network Egress between regions.
I can use instance connection name as a host for my config
This is incorrect. If you are using the Cloud SQL Proxy to connect, it can create a Unix domain socket (at /cloudsql/INSTANCE_CONNECTION_NAME) that can be used to connect to your instance. However the proxy only authenticates your connection - it still needs a valid connection path (Public vs Private).
As you can see in this PostgreSQL pricing documentation there is no difference in the pricing as you use the public IP or the connection name on the Cloud SQL side. If you want to keep the cost as low as possible you can try to keep your Compute Engine instances in the same region, or at least in the same continent as your Cloud SQL instance.
I'm trying to connect to my Redshift database from my AWS Lambda function:
con = psycopg2.connect(
dbname="my_dbname",
host="my_url",
port= 5439,
user="username",
password="my_password")
cur = con.cursor()
But I can't access my database, my function raises the following error:
OperationalError: could not connect to server: Connection timed out
Is the server running on host "my_url" (54.217.83.88) and accepting
TCP/IP connections on port 5439?
Can i get some help with this please ? (and if possible I'd like to have a very detailed answer, because I'm new to AWS )
PS: I know that I have to configure the VPC, but I don't know what to do exactly
Thanks you in advance
Your goal is to have the AWS Lambda function communicate with the Amazon Redshift cluster within the same VPC, via private IP address. This keeps the traffic within the VPC.
The AWS Lambda function will need to be configured to connect to a private subnet in the same VPC as the Amazon Redshift cluster.
See: Configuring a Lambda Function to Access Resources in an Amazon VPC
Either connect to the Private IP address of the cluster or (preferably) follow the directions on Managing Clusters in an Amazon Virtual Private Cloud (VPC) to enable DNS Hostnames and DNS Resolution on the VPC so that the host name will automatically resolve to the Private IP address.
The Security Group associated with the Amazon Redshift cluster will need to permit inbound traffic on port 5439 from the CIDR range of the the VPC (or as appropriate).
See: Amazon Redshift Cluster Security Groups
When the python lambda function is executed I get "Task timed out after 3.00 seconds" error. I am trying the same example function.
When I try to run the same code from eclipse it works fine and I can see the query result. Same way I can connect to the db instance from local-machine Mysql workbench without any issues.
I tried creating a role with with full administrator access policy for this lambda function and even then its not working fine. The db instance has a vpc and I just added my local ip address there using the edit CIDR option so I can access the instance through my local machine workbench. For VPC, subnet and security group parameter in lambda function I gave the same values as I have in the RDS db instance.
I have also increased the timeout for lambda function and still I see the timeout error.
Any input would be appreciated.
For VPC, subnet and security group parameter in lambda function I gave the same values as I have in the RDS db instance.
Security groups don't automatically trust their own members to access other members.
Add a rule to this security group for "MySQL" (TCP port 3306) but instead of specifying an IP address, start typing s g into the box and select the id of the security group that you are adding the rule to -- so that the group is self-referential.
Note that this is probably not the correct long-term fix, because if your Lambda function needs to access the Internet or most AWS services, the Lambda function needs to be on a private subnet behind a NAT device. That does not describe the configuration of the subnet where your RDS instance is currently configured, because you mentioned adding your local IP to allow access to RDS. That suggests your RDS is on a public subnet.
See also Why Do We Need Private Subnets in VPC for a better understanding of public vs. private subnets.