I have deployed my EKS cluster in private subnetes, Now this subnets have internet access using NAT gateway. I wanted to find out how much data transfered from Each pod to NAT gateway ??
You don't, really.
There is no available metric available at that level of granularity. You can see the total bytes transferred in/out for each NAT gateway, but it won't tell you what percentage each pod (or any other services in the private subnet for that matter) are accounted for of the total bytes transferred.
By default, containers from all pods in an EKS cluster share network interface(s) from the host(s) of the cluster, which is more cost effective and saves available IP addresses in your VPC, but means you can't track individual container traffic with flow logs. In theory, (I don't recommend this) you could configure your cluster to assign a VPC network interface for each container in your cluster and track traffic to your NAT gateway(s) independently with VPC flow logs then filter/aggregate the data, relate it back to the origin pods in order to determine how much traffic each pod sent to the NAT gateway. In practice, this is difficult and expensive.
See How can I find the top talkers or contributors to traffic through the NAT gateway in my VPC? for more detail.
Another option may be to use a proxy container for requests bound for the NAT gateway and have the proxy collect the metrics per pod. You'd have to configure the pods to use the proxy, share pod information to the proxy, and configure the proxy to track/provide the metrics. I don't know of any off-the-shelf tools that do this.
Related
I have an EC2 based client that calls this public DNS of this AWS ELB in the same region and I am trying to save money on EC2-Internet public traffic and want to keep all the data within AWS cloud.
I want to know since I am calling from one AWS service to another. Does AWS services internally know how to keep this traffic within AWS ecosystem and save me internet data transfer charges?
Is setting up a VPC between the EC2 client -> AWS ELB is the only way to save on public internet traffic?
Thank you
what you are looking for is an internal load Balancer
The nodes of an internal load balancer have only private IP addresses. The DNS name of an internal load balancer is publicly resolvable to the private IP addresses of the nodes. Therefore, internal load balancers can only route requests from clients with access to the VPC for the load balancer.
You dont have to create vpc for that, default vpc will also work just make sure your ec2 and internal LB are in the same private vpc and subnet as prerequisite.
How to do it, read here
Coming to question Does AWS services internally know how to keep this traffic within AWS ecosystem and save me internet data transfer charges
If its within the same region using internet gateway it is free, if it uses nat gateway within same region it will cost, but if request falls cross region it is not free, Ref: Data transfer cost
We have a GKE Autopilot Cluster and an external Address/Cloud NAT set up. For certain Pods we want to ensure that all their outgoing traffic (layer 4) is routed through that external address.
The only possibilities I can think of is to make the whole Cluster private (and thus enforce use of the Cloud NAT) or to use a Service Mesh solution which could perhaps intercept all pakets via ebpf?
Are there other solutions to enforcing a routing to one external Address?
With the time being, there is no way to do this for the GKE Autopilot Cluster.
But by the end of October, there will likely be an upgrade to the Egress NAT policy that will enable users to setup SNAT based on pod labels, namespaces, and even the destination IP address.
I want design AWS architecture like this, but not sure how to handle high bandwidth (>100GB) traffic.
A kubernetes cluster with lots of microservices , both frontend and backend. An LB in front of the worker nodes. K8s replica can scale high bandwidth traffic.
My question is where should I create the Kubernetes cluster? I know there is no bandwidth constraints in Public subnet, but AWS NAT Gateway has bandwidth constraints. What is the approach by big companies to serve high bandwidth through NAT Gateway. Or should I put my K8s cluster in public subnet itself.?
Any help is appreciated .Thanks
If the burst bandwidth of a NAT Gateway doesn't meet your requirements (currently 45Gbps), you will most likely have to configure a NAT instance.
(Bear in mind you can have one NAT Gateway per AZ)
The bandwidth of a NAT instance is dependent upon the the instance type you use.
There is more information about the comparison here
I would stay away from deploying your services in a public subnet unless it's absolutely necessary.
I have one VPC where i configured NAT Gateway. Another VPC(s) do not have any "public subnet" nor IGW. I would like to share single NAT Gateway among many VPCs.
I tried to configure Routing table but it does not allow to specify NAT Gateway from different VPC.
As posible solution, I installed http/s proxy in VPC with IGW and configured proxy settings on every instance in different VPC. It worked, but I would like use NAT Gateway due to easier management.
Is it possible to make this kind of configuration at AWS?
There are few VPCs and I do not want to add NAT Gateway to each VPC.
Zdenko
You can't share a NAT Gateway among multiple VPCs.
To access a resource in another VPC without crossing over the Internet and back requires VPC peering or another type of VPC-to-VPC VPN, and these arrangements do not allow transit traffic, for very good reasons. Hence:
You cannot route traffic to a NAT gateway through a VPC peering connection, a VPN connection, or AWS Direct Connect. A NAT gateway cannot be used by resources on the other side of these connections.
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-nat-gateway.html#nat-gateway-other-services
The instances in the originating VPC are, by definition, "on the other side of" one of the listed interconnection arrangements.
AWS Transit Gateway now provides an option to do what you wish, although you will want to consider the costs involved -- there are hourly and data charges. There is a reference architecture published in which multiple VPCs share a NAT gateway without allowing traffic between the VPCs:
https://aws.amazon.com/blogs/networking-and-content-delivery/creating-a-single-internet-exit-point-from-multiple-vpcs-using-aws-transit-gateway/
You basically have 3 options
connect to a shared VPC (typically in a shared "network" account) that holds the NAT via VPC peering. No additional costs for the VPC peering, but cumbersome to setup if you have a lot of accounts
same, but using Transit Gateway. A Peering Attachment is almost the same cost as a single NAT, so this will only save costs if you use multiple NAT gateways to have a high bandwidth
Setup a shared VPC (e.g. in an infrastructure account that holds the NAT. Then share private subnets via AWS resource manager (RAM) to the VPCs that need outgoing access. This has the additional benefit you have a single place where you allocate VPC IP ranges and not every account needs to bother with setting up the full VPC. More details in AWS VPC sharing best practices. This setup avoids both the Transit Gateway costs and the burden of setting up VPC peering. But needs more careful planning to keep things isolated (and likely not everything in the same VPC)
Got a quick question which might be totally silly but it's early in the morning. So I have a standard AWS VPC with an ELB, NAT instance and 2x EC2 instances for the application code. By the looks of the image bellow the internet gateway passes traffic the ELB and NAT instance. My question is why isn't the NAT instance in front or behind the ELB ? it looks like that the single bottleneck in this VPC could be the NAT instance if all traffic is going through there.
The NAT (Network Address Translation) server is used to provide outbound Internet connectivity for Amazon EC2 instances in a private subnet.
Incoming traffic will enter via the Load Balancers and any responses to this traffic will also exit via the Load Balancers. The Elastic Load Balancing service automatically scales based upon the amount of traffic (there is also a charge for traffic transferred).
If an EC2 instance in a private subnet wishes to initiate a connection to the Internet (eg to download updates, or to communicate with Amazon S3), it cannot send traffic "out" of the load balancers. Instead, the subnet would be configured to route traffic to the NAT server, which acts as a proxy for requesting data from the Internet.
It is possible that the NAT server could become a bottleneck. If so, modify the instance to use a larger Instance Type -- this not only adds CPU and RAM, but also network bandwidth.
In some cases, people might also use a NAT server for incoming traffic -- either as a jump-box for administrative purposes (to login to an instance in a private subnet) or to forward specific ports to a private server (via port forwarding). However, best practice would be to separate these functions to a different instance for security and management purposes.
Additional information: Since writing this answer, AWS has introduced a Managed NAT Gateway that can automatically scale. It is created in a single AZ, so you might want to run it in two AZs for High Availability.
I'm not sure how its working, if the loadbalacer is terminating over the APP Tier , then the instance launched in these subnet will have route-table configured with IGW not the NAT instance, which raises a question how to make outbound traffic on the public network which is configured over a loadbalalncer