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
Related
I have a simple Java application listening on port 8443. I've deployed it as a Docker image into Fargate, it has a public IP address and I can access it through the IP address just fine.
The problem is every time I redeploy the image, it gets a new IP address.
I would like to have a static hostname. For example, when I use Elastic Beanstalk and deploy a website, it will get a hostname. How do I get the same thing?
I've been following the documentation for one whole day and didn't make any progress. I've created load balancers, targets, listeners, accelerators, nothing seems to work. For example, when creating a load balancer, it doesn't tell me what the hostname is.
I'm pretty sure this is supposed to be something really easy, but I just cannot figure it out. What am I doing wrong?
You may want to create an Application Load Balancer and register your Fargate services into a Target Group for the load balancer. You have to register your services only once, if you redeploy newer versions afterwards, they will be automatically added to the Target Group.
The Application Load Balancer will provide a publicly accessible hostname. Example:
For your load balancer to be reachable, it needs to be in a public subnet. It also needs to have a security group which allow traffic from the public internet and also allows traffic to the registered targets.
Steps to create an ALB for your ECS cluster: AWS docs
Registering ECS services into a Target Group: AWS docs
Update:
The problem is that when I create a Target Group I cannot associate it with the service.
When you create the cluster, the AWS console asks you if you would want to deploy your containers in a VPC. You have to select yes, and create a VPC:
Afterwards, you may want to get the id of the VPC (for example, in my case: vpc-0e6...) and you may want to go into your EC2 console an create a new Application Load Balancer, placing it into that VPC
ALB:
Now, when you create a new Fargate service, you should see the Application Load Balancer:
I have service in AWS ECS and service discovery maintains domain records like web.local that points to tasks in that service.
I would like Network Load Balancer to point at domain web.local instead of IP or Instance.
I know when I create service I specify Load Balancer and it magically setups everything for me. I can't find where web.local is specified or service discovery.
I checked target group, etc.
There is an option to use service discovery, If you want to enable it you may do it while you are creating the ECS service.
The namespace name is the keyword after the dot(.), in our case it will be .local.
There is also an option to add the Service discovery name* this is the keyword before the dot(.).
Ref: https://docs.aws.amazon.com/AmazonECS/latest/developerguide/service-discovery.html
Update: You don't need it to point it to NLB if you are using service discovery option of ECS. There will be absolutely no role of the target group with it. ECS service will directly point a DNS name to your containers. If you want to use Load balancer bases service discovery then it's a different story altogether, Then you have to create a private hosted zone yourself and point it to your load balancer. But in the end, you can only choose one.
I have a scenario where I have to deploy multiple micro-services on AWS ECS. I want to make services able to communicate with each other via APIs developed in each micro-service. I want to deploy the front-end on AWS ECS as well that can be accessed publicly and can also communicate with other micro-services deployed on AWS ECS. How can I achieve this? Can I use AWS ECS service discovery by having all services in a private subnet to enable communication between each of them? Can I use Elastic Load Balancer to make front-end micro-service accessible to end-users over the internet only via HTTP/HTTPS protocols while keeping it in a private subnet?
The combination of both AWS load balancer ( for public access) and Amazon ECS Service Discovery ( for internal communication) is the perfect choice for the web application.
Built-in service discovery in ECS is another feature that makes it
easy to develop a dynamic container environment without needing to
manage as many resources outside of your application. ECS and Route 53
combine to provide highly available, fully managed, and secure service
discovery
Service discovery is a technique for getting traffic from one container to another using the containers direct IP address, instead of an intermediary like a load balancer. It is suitable for a variety of use cases:
Private, internal service discovery
Low latency communication between services
Long lived bidirectional connections, such as gRPC.
Yes, you can use AWS ECS service discovery having all services in a private subnet to enable communication between them.
This makes it possible for an ECS service to automatically register
itself with a predictable and friendly DNS name in Amazon Route 53. As
your services scale up or down in response to load or container
health, the Route 53 hosted zone is kept up to date, allowing other
services to lookup where they need to make connections based on the
state of each service.
Yes, you can use Load Balancer to make front-end micro-service accessible to end-users over the internet. You can look into this diagram that shows AWS LB and service discovery for a Web application in ECS.
You can see the backend container which is in private subnet, serve public request through ALB while rest of the container use AWS service discovery.
Amazon ECS Service Discovery
Let’s launch an application with service discovery! First, I’ll create
two task definitions: “flask-backend” and “flask-worker”. Both are
simple AWS Fargate tasks with a single container serving HTTP
requests. I’ll have flask-backend ask worker.corp to do some work and
I’ll return the response as well as the address Route 53 returned for
worker. Something like the code below:
#app.route("/")
namespace = os.getenv("namespace")
worker_host = "worker" + namespace
def backend():
r = requests.get("http://"+worker_host)
worker = socket.gethostbyname(worker_host)
return "Worker Message: {]\nFrom: {}".format(r.content, worker)
Note that in this private architecture there is no public subnet, just a private subnet. Containers inside the subnet can communicate to each other using their internal IP addresses. But they need some way to discover each other’s IP address.
AWS service discovery offers two approaches:
DNS based (Route 53 create and maintains a custom DNS name which
resolves to one or more IP addresses of other containers, for
example, http://nginx.service.production Then other containers can
send traffic to the destination by just opening a connection using
this DNS name)
API based (Containers can query an API to get the list of IP address
targets available, and then open a connection directly to one of the
other container.)
You can read more about AWS service discovery and use cases amazon-ecs-service-discovery and here
According to the documentation, "Amazon ECS does not support registering services into public DNS namespaces"
In other words, when it registers the DNS, it only uses the service's private IP address which would likely be problematic. The DNS for the "public" services would register to the private IP addresses which would only work, for example, if you were on a VPN to the private network, regardless of what your subnet rules were.
I think a better solution is to attach the services to one of two load balancers... one internet facing, and one internal. I think this works more naturally for scaling the services up anyway. Service discovery is cool, but really more for services talking to each other, not for external clients.
I want to deploy the front-end on AWS ECS as well that can be accessed publicly and can also communicate with other micro-services deployed on AWS ECS.
I would use Service Discovery to wire the services internally and the Elastic Load Balancer integration to make them accessible for the public.
The load balancer can do the load balancing on one side and the DNS SRV records can do the load balancing for your APIs internally.
There is a similar question here on Stack Overflow and the answer [1] to it outlines a possible solution using the load balancer and the service discovery integrations in ECS.
Can I use Elastic Load Balancer to make front-end micro-service accessible to end-users over the internet only via HTTP/HTTPS protocols while keeping it in a private subnet?
Yes, the load balancer can register targets in a private subnet.
References
[1] https://stackoverflow.com/a/57137451/10473469
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.
I have front-end hosted on a server which calls the Back-end server i.e. an Elastic Load Balancer(ELB), and using Elastic Beanstalk for deployments hence it takes care of autoscaling.
Ember/Front-end -> ELB -> Autoscaled EC2 instances with Nginx servers
Now I want to add API Gateway in between and ensure that ELB takes requests from API Gateway only. I found that-> here <-
But, I am using AWS Certificate manager to push my SSL certififcates, not sure how to use the PEM file/cert provided by API Gateway.
Is it possible to push the API Gateway provided Client Side Cert file through Certificate manager(console/cli/anywhere) along with the SSL certs that I bought ?
Is it possible to terminate SSL at ELB and use the API Gateway key.
To my horror, do I need to manually configure the certs on nginx config in the .ebextensions file ? if yes, the is there a better way to not push the file son the code repo and use them separately ?
The best way to do this is:-
If you are using Elastic Beanstalk in a VPC and are not of a view to rebuild the configuration. Then create an Elastic Load Balancer, attach it to a Target group, which targets an Autoscaling group's instances(make sure to attach the Target group in the Autoscaling group configuration as well, so that it keeps connected even when the instances are up/downscaled).
Or build a new conf. using the Network Load Balancer. Make sure that the Network load balancer is of scheme private i.e. not exposed to public/internet.
Next step is to create a VPC Link in API Gateway(you see an option in the API Gateway Console left menu-bar).
More information: https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-private-integration.html