I have a lambda function which must be placed in a VPC because it communicates over a VPC peering connection. I also need it to upload to my Elasticsearch Service domain (not in a VPC because it is publicly accessible). But currently when Lambda tries to talk to ES, it times out.
I ran into this problem with Secrets Manager, so I went into the lambda's VPC, clicked on Endpoints, and created a Secrets Manager endpoint. I would like to do the same with Elasticsearch Service, but it doesn't show up in my list of AWS Services, which is odd because it definitely is an AWS Service.
Any idea how I can add an endpoint for Elasticsearch Service in my VPC so my Lambda function can talk to it? Thanks!
There is no VPC endpoint for ES. The services that support the endpoints are listed here.
Regarding the timeout, you would have to provided detailed description of your VPC setup, subnets, route tables, lambda and explain how did you setup your ES and how do you try to access it from VPC. Its difficult to speculate why it times out without all the details.
But since your ES is public, one possibility could be because lambda in VPC will not be able to connect to it without the use of NAT gateway. By default, lambda in a VPC does not have internet connectivity.
Related
I am connecting to AWS DocumentDB from a Lambda function. In order to be able to do this I had to attach lambda to the default VPC (that's where DocumentDB cluster is running) and the default (public) subnets. But, this has caused my Lambda to timeout whenever trying make an outbound request, e.g. push message to SQS. This, I want to avoid.
So what is the recommended way of connecting to DocumentDB without loosing functionality that occurs when putting Lambda in the VPC? There's gotta be a simple solution.
Lambda functions in a VPC never get a public IP address. So if the function needs to access both VPC resources and other resources outside of the VPC the function has to be deployed only to private subnets with routes to a NAT Gateway.
Alternatively, if the only external resources you need to access are other AWS services, then you could add VPC Endpoints for those services to the VPC.
What is the difference between Private Link and VPC endpoint? As per the documentation it seems like VPC endpoint is a gateway to access AWS services without exposing the data to internet. But the definition about AWS private link also looks similar.
Reference Link:
https://docs.aws.amazon.com/vpc/latest/userguide/endpoint-services-overview.html
Does Private Link is the superset of VPC endpoint?
It would be really helpful if anyone provides the difference between these two with examples!
Thanks in Advance!
AWS defines them as:
VPC endpoint — The entry point in your VPC that enables you to connect privately to a service.
AWS PrivateLink — A technology that provides private connectivity between VPCs and services.
So PrivateLink is technology allowing you to privately (without Internet) access services in VPCs. These services can be your own, or provided by AWS.
Let's say that you've developed some application and you are hosting it in your VPC. You would like to enable access to this application to services in other VPCs and other AWS users/accounts. But you don't want to setup any VPC peering nor use Internet for that. This is where PrivateLink can be used. Using PrivateLink you can create your own VPC endpoint services which will enable other services to use your application.
In the above scenario, VPC interface endpoint is a resource that users of your application would have to create in their VPCs to connect to your application. This is same as when you create VPC interface endpoint to access AWS provided services privately (no Internet), such as Lambda, KMS or SMS.
There are also Gateway VPC endpoints which is older technology, replaced by PrivateLink. Gateways can only be used to access S3 and DynamoDB, nothing else.
To sum up, PrivateLink is general technology which can be used by you or AWS to allow private access to internal services. VPC interface endpoint is a resource that the users of such VPC services create in their own VPCs to interact with them.
Suppose there is a website xyz.com that I am hosting in a bunch of Ec2 instances, exposed to the outside world thru a Network load balancer.
Now, a client who has his/her own AWS account, wants to access this xyz.com from an Ec2 running in their aws account.
One approach is to go thru the Internet.
However the client wants to avoid the internet route.
He/she wants to use the AWS backbone to reach xyz.com.
The technology that enables that, is AWS Private link.
(note that if you search for Private Link in the AWS services, there will be none.
You will get "End point services" as the closest hit)
So, this is how to route traffic through the AWS backbone:
I, the owner of xyz.com, will create a VPC End Point Service (NOTE the keyword Service here)
The VPC End point service will point to my Network load balancer.
I will then give my VPC End point service name to the client.
The client will create a VPC End Point (NOTE.. this is different from #1).
While creating it, the client will specify the VPC End Point Service name (from #1) that he got from me.
I can choose to be prompted to accept the connection from the client to my VPC End point service.
As soon as I accept it, then the client can reach xyz.com from his/her EC2 instance.
There is no Internet, no direct connect or VPN.. this simply works; and its secure.
And which technology enabled it.. AWS Private link !!!
PRIVATE LINK IS THE ONLY TECHNOLOGY THAT ALLOWS 2 VPCS TO CONNECT THAT HAVE OVERLAPPING CIDR RANGES.
A useful way in understanding differences is in how they technically connect private resources to public services.
Gateway Endpoints route traffic by adding prefix lists within a VPC route table which targets the Gateway endpoint. It is a logical gateway object similar to a Internet Gateway.
In contrast, an Interface Endpoint uses Privatelink to inject into a VPC at the subnet level, via an Elastic Network Interface (ENI), giving network interface functionality, and therefore, DNS and private IP addressing as a means to connect to AWS public services, rather than simply being routed to it.
The differences in connections offer differing advantages and disadvantages (availability, resiliency, access, scalability, and etc), which then dictates how best to connect private resources to public services.
Privatelink is simply a very much abstracted technology to allow a more simplified connection by using DNS. The following AWS re:Invent offers a great overview of Privatelink: https://www.youtube.com/watch?v=abOFqytVqBU
As you correctly mentioned in the question that both VPC endpoint and AWS private link do not expose to internet. On AWS console under VPC, there is a clear option available to create an endpoint. But there is no option/label to create AWS private link. Actually, there is one more option/label called endpoint service. Creating endpoint service is one way to establish AWS private link. At one side of this AWS private link is your endpoint service and at the other side is your endpoint itself. And interestingly we create both these sides in two different VPCs. In other words, you are connecting two VPCs with this private link (instead of using internet or VPC peering).
understand like,
VPC1 got endpoint service ----> private link -----> VPC2 got endpoint
Here endpoint service side is service provider while endpoint is service consumer. So when you have some service (may be some application or s/w) that you think other VPC endpoints can consume you create endpoint service at your end and consumers will create endpoints at there end. When consumers create endpoints at their end they have to give/select your service name and thus private link will be established with your service.
Ultimately you can have multiple consumers of your service just like one to many relationship.
I'm trying to test AWS RDS proxy so I created a lambda function and done all steps that are present in this official link
https://aws.amazon.com/blogs/compute/using-amazon-rds-proxy-with-aws-lambda
store RDS credentials in Secret Manager
create new role and also add Trust Policy
in lambda function, from the AWS console, add proxy and its status is available.
When I execute the lambda function, it times out with no errors it seems like the error might be on connecting to db with rds proxy because when I run the lambda function again without proxy, it works just fine.
I initially thought that it might be a security group issue, so I edit the security group of RDS Proxy and update inbound and allow 0.0.0.0 (outbound was already 0.0.0.0).
I used defaut VPC in RDS Database and RDS Proxy. The endpoint of RDS database is public.
Since RDS proxy is not available outside the VPC. Configure your lambda function to run inside the VPC. The following link will help:
https://docs.aws.amazon.com/lambda/latest/dg/configuration-vpc.html
Late answer.. thought these might help others.
You have to keep your lambdas inside the same VPC and subnets to access RDS proxy.
In any case if you want to access third party web api from your lambda, you have make the lambda subnets private (no Internet Gateway in route table) and assign a NAT gateway which is tied with a public subnet.
If you are accessing other AWS services which are out of VPC like S3, Secret Manager etc. then you have to create VPC endpoints for those services in your VPC.
I'd like to have a lambda expression that every hour makes a query on RDS database, pull some ARN (device tokens) and then sends these devices a notification via SNS. My desire is to remain inside the VPC and I'd like to avoid using NAT due to its cost. Should i create a VPC endpoint (is this called AWS PrivateLink?) that can reach out SNS+RDS? Is NAT and Endpoint similar in billing? Globally is this the right way to achieve a "cron sending notifications" on AWS?
RDS is reachable inside the VPC without the endpoint isn't it?
This is totally possibly
Your lambda can run in a private subnet in the VPC that communicates with your RDS database over the network on port 3306. Make sure your security group and NACL rules allow this.
You then need to create a VPC endpoint to your SNS service. Be sure your route table includes this route.
The main difference between VPC endpoints and AWS Privatelink is the following:
A VPC endpoint enables you to privately connect your VPC to supported AWS services. SNS, Kinesis, SQS, S3,....
While AWS Privatelink is more about creating your own application in your VPC and configuring it as an AWS PrivateLink-powered service (referred to as an endpoint service). Other AWS principals can create a connection from their VPC to your endpoint service using an interface VPC endpoint.
VPC endpoints are free. Nat Gateways cost per hour per GB.
I need to create an AWS Lambda that uses the AWS SDK, and communicates through a VPC Endpoint, in order to dynamically adjust routes found in a VPC route table. The problem is that the VPC Endpoint list of supported services does not list "VPC API" (though it does mention EC2 API). Does this mean my goal simply isn't possible through a VPC Endpoint, or am I interpreting the documentation too strictly?
Also, to be clear, I'm expressly avoiding a NAT Gateway / IGW. This is why my question centers on VPC Endpoints.
Incidentally, here is a related question.
I think you're looking for the AWS CLI functions for VPC configuration. VPC is a basic component in AWS, and should not have any gaps in feature configuration.