You write a Lambda function that needs to connect to an RDS MySQL database.
You use a CD pipeline to deploy the Lambda function in the same VPC subnet as the RDS database so that they can communicate.
However, you find that the deployed Lambda function is not able to connect to the internet.
How would you resolve this problem?
Click on the arrows to vote for the correct answer
A. B. C. D.Correct Answer - B.
Option A is incorrect: Because the Lambda function cannot communicate with the RDS database if it is in a different VPC.Option B is CORRECT: When the Lambda function is in a VPC, the VPC needs to access the internet.
The NAT gateway has a public IP address and connects to the internet.
Option C is incorrect: Because the Lambda function will lose the connection with the RDS database if it is outside of the VPC.Option D is incorrect: Because the Lambda function does not have an access control list.
In this scenario, VPC should have internet access.
Reference:
https://docs.aws.amazon.com/lambda/latest/dg/configuration-vpc.htmlThe issue is that the Lambda function, which needs to connect to an RDS MySQL database, is deployed in the same VPC subnet as the database, but it is unable to connect to the internet. This is because by default, Lambda functions deployed in a VPC do not have internet connectivity unless they are configured to do so explicitly.
To resolve this issue, there are a few possible options:
Option A: Modify the pipeline to deploy the Lambda function in the default VPC rather than the same VPC as RDS.
This option would allow the Lambda function to connect to the internet by default, as the default VPC has an internet gateway attached to it. However, it would mean that the Lambda function and the RDS database would no longer be in the same VPC subnet, which could affect their ability to communicate efficiently.
Option B: Configure a NAT gateway in the VPC and route the outbound traffic to the NAT gateway.
This option involves setting up a Network Address Translation (NAT) gateway in the VPC, which allows the Lambda function to access the internet through the NAT gateway. The NAT gateway acts as a proxy between the Lambda function and the internet, allowing the Lambda function to communicate with the RDS database in the same VPC subnet while also providing internet connectivity.
Option C: Deploy the Lambda function outside of the custom VPC.
This option involves deploying the Lambda function outside of the VPC altogether, which would allow it to access the internet by default. However, this would also mean that the Lambda function would not be able to communicate directly with the RDS database in the same VPC subnet.
Option D: Open the outgoing port in the Lambda function access control list.
This option involves modifying the security group associated with the Lambda function to allow outbound traffic on the required port(s) for connecting to the RDS database. However, this option alone may not be sufficient to allow the Lambda function to connect to the internet, as it would still be deployed in a VPC without internet connectivity by default.
In conclusion, the most appropriate solution to this problem would be option B: Configure a NAT gateway in the VPC and route the outbound traffic to the NAT gateway. This would allow the Lambda function to connect to the internet through the NAT gateway while still being able to communicate with the RDS database in the same VPC subnet.