I have a quick question regarding AWS EKS that whenever I create a K8s service with of type LoadBalancer, it provisions a classic ELB backed the EC2 where services are running. Now whenever I try to hit the Load Balancer ELB from the Internet, it returns ERR_EMPTY_RESPONSE error. If I navigate back to ELB and look at the instances behind ELB, it shows the status of EC2 instances as OutOfService.
This happens either I use my own K8s deployments & services or the one provided with documentation. Anyone can help me with this? More over, is there any way to provision a different type of Load Balancer for a K8s service? Thanks.
This is default behavior or K8S with on cloud providers , A service type Load Balancer will spins up real one which affect cost.
Better to use K8S Ingress as best practice and can use as Endpoint or you can add under External Load Balancer.
Related
Background
Current State: I currently have a nlb that routes to an nginx server running on an ec2 instance.
Goal
I am trying to replace the nginx ec2 instance with a fargate service that runs nginx.
I would like to keep the current nlb and set the fargate cluster as the target group for the existing nlb.
Problem
according to aws documentation, aws ecs fargate cluster service supports loadbalancing with nlb or alb: https://docs.aws.amazon.com/AmazonECS/latest/userguide/service-load-balancing.html
when I try to deploy the nginx task, in the load balancing section,
there is only an option to select an existing alb or create a new
alb.
I tried changing the task protocol to TCP and UDP--regardless of
the protocol, when I try to deploy the task as a service, the only
load balancer option is still application load balancer.
Question
How do I load balance to a fargate cluster service task using an nlb? Am I missing a specific setting somewhere?
If you cannot set the fargate cluster as a target group for an nlb directly, would it be reasonable to route traffic from an nlb to an alb and then set the alb target group as a fargate cluster?
You can absolutely use an NLB with an ECS Fargate service. I've done this before many times. My guess is you are simply encountering a bug in the AWS web UI. I've always used Terraform to deploy this sort of thing. I just checked in the ECS web UI, and on the 2nd step of creating a new ECS service I get the option of using a Network Load Balancer:
If your view doesn't look like that, try switching from the "New ECS Experience" in the UI which is still fairly beta and missing a lot of features.
I just went back and checked, and in the new ECS UI they are currently missing the option to select an NLB, so you have to continue using the old version of the UI for now until they fix that. I suggest continuing to use the old UI until they phase it out, because the new ECS UI is still missing a lot of features.
I was using AWS ECS fargate for running my application. I am migrating to AWS EKS. When I use ECS, I deployed a ALB to route request to my service in ECS cluster.
In kubernete, I read this doc https://kubernetes.io/docs/concepts/services-networking/service/#loadbalancer, it seems that Kubernete itself has a loadbalance service. And it seems that it creates an external hostname and IP address.
so my question is do I need to deploy AWS ALB? If no, how can I pub this auto-generated hostname in route53? Does it change if I redeploy the service?
Yes you need it to create Kubernetes Ingress using AWS ALB Ingress Controller, the following link explain how use ALB as Ingress controller in EKS: This
You don't strictly need an AWS ALB for apps in your EKS cluster, but you probably want it.
When adopting Kubernetes, it is handy to manage some infrastructure parts from the Kubernetes cluster in a similar way to how you mange apps and in some cases there are a tight coupling between the app and configuration of your load balancer, therefore it makes sense to manage the infrastructure the same way.
A Kubernetes Service of type LoadBalancer corresponds to a network load balancer (also known as L4 load balancer). There is also Kubernetes Ingress that corresponds to an application load balancer (also known as L7 load balancer).
To use an ALB or Ingress in Kubernetes, you also need to install an Ingress Controller. For AWS you should install AWS Load Balancer Controller, this controller now also provides features in case you want to use a network load balancer, e.g. by using IP-mode or expose services using an Elastic IP. Using a pre-configured IP should help with using Route53.
See the EKS docs about EKS network load balancing and EKS application load balancing
As already mentioned from the other guys, yes it is NOT required but it is very helpful to use an ALB.
There are a couple of different solutions to that.. my favorite solution is
Use an Ingress Controller like the ingress-nginx (there are multiple different Ingress Controllers available for Kubernetes, a very good comparison is provided here
Configure the IngressController Service to use NodePort and use a port like 30080
Create an own AWS ALB with Terraform for an example and add the NodePort 30080 to the TargetGroup
Create a Ingress resource to configure the IngressController
If you still have some questions, just ask them here :)
No you don't need ALB and yes, you can use Route53 in an automated manner. Here's a nice article that describes the latter:
https://www.padok.fr/en/blog/external-dns-route53-eks
I was trying to host my API (.NET Core Web API) on Elastic Kubernetes Service in AWS. I followed around some tutorials and get it on EKS now. Everytime I run kubectl get pods I can see my service there.
Then in order to exposed the service to API Gateway, I was told that need to create a Load Balancer. So I create a Load Balancer using the kubectl expose command and success. Now I can see my Load Balancer is hosted on EC2 with a specific DNS address and able to see it via kubectl get svc command.
Here is the problem, according to tutorials, when I access to the specific DNS name with port, example: *****.ap-southeast-1.elb.amazonaws.com:8000, I should be able to access.
But no, all I get is empty response error from browser. When I go over EC2 pages to check my Load Balancer, I found that all the instances under the ELB is Out Of Service.
The Status of the ELB is: 0 of 6 instances in service
When I switched over to Instances tab, all the 6 instances are showing Out Of Service.
Is this why I could not access to the DNS address? And how can I make the instances In Service?
FYI: What I want to do eventually is using API Gateway to connect to the API on EKS.
Thank you very much if anyone knows how to solve this.
I've built an AWS CodePipeline to build and deploy containers into Fargate managed EC2 instances. Ref AWS CodePipeline
One of the services is a web server and I'm attempting to access it from the public which is possible via a public assigned IP address; however, that's not very useful as each deployed container receives a fresh IP address.
I understand it's possible to setup Elastic IP addresses or point a domain to the container service but I'd think there is an easier way.
EC2 instances can be launched with the option of providing a Public DNS...
Is it possible to launch container services with a static public DNS record? If so, how?
Most Common Choice: ALB
Although it's not free, normally if you want a public DNS name to an ECS service (fargate or EC2) you'd front it with a load balancer (which can also do SSL termination, if you so desire).
Because of that, AWS makes it easy to create a load balancer or add your service to an existing target group when you're setting up a service. I don't think you can change that after the fact, so you may need to recreate the service.
Finally, when you have a load balancer in front of the ECS service, you just need to set up a CNAME or an A ALIAS in Route53 (if you're using Route53) to direct a DNS name to that load balancer.
AWS has a walkthrough from 2016 on the AWS Compute Blog quickly describing how to set up an ECS service and expose it using an Application Load Balancer.
ECS Service Connect
ECS Service Connect was announced at ReInvent 2022, and seems to let you connect to a load-balanced ECS service without using an ALB or an API Gateway.
CloudMap / Service Discovery / API Gateway
With ECS Service Discovery and AWS CloudMap, you can use an API Gateway. Your load balancing options are more limited, but API Gateways are billed based on usage rather than hours, so it can potentially save costs on lower-volume services. You can also use a single API Gateway in front of multiple ECS services, which some people are going to want to do anyway. This approach is less commonly employed, but might be the right path for some uses.
You can use ECS Service Discovery for registering your containers in a private DNS namespace - unfortunately this is not possible with public DNS.
But, what you can do, is to have a script
fetch your containers' public IP after redeployment and
upsert your public Route 53 record set with that IP.
In this article, we describe how to do exactly that by using a generic lambda function.
When I set up an ECS Fargate service for the first time, the setup wizard seems to have automatically (?) created a load balancer for me. I was able to access the web app that I created via the URL at Amazon ECS -> Clusters -> {my cluster} -> {my service} -> Target Group Name (under Load Balancing in the Details tab) -> {my target group} -> Load Balancer -> DNS Name
I am trying to create a High availability Kubernetes cluster for my CI/CD pipeline for deploying my Spring Boot microservices.
I am following the following kubernetes official document for exploring:
https://kubernetes.io/docs/setup/independent/high-availability/
My confusion is that - when reading, I found that need to create Load Balancer for kube-api server for forming the HA cluster. Actually I am planning to use AWS Ec2 machines for forming the cluster. So I will get Elastic Load Balancer from AWS. So do I need to create separate Load balancer as described in document or can I use the ELB for the same ?
You can use only ELB for this purpose.
Hopefully these Kubernetes and ELBs, The Hard Way instructions will be useful for you.