I am trying to set up Treafik in my Kubernetes cluster running on AWS. I am having problems understanding the host-url that is used in the ingress-service. The tutorial in their page was nice but the think is that running in minikube you have just one node so you are going to map that IP to the Host that you are going to use in Treafik.
I don't know which IP should I map in case of Kubernetes in AWS. The master url? What happens when I have multiple masters?
The host-url is the external IP of the Traefik Load-Balancer in AWS. In minikube there is no external IP so I think they did it this way (to use the minikube IP) for testing.
I suffered a bit to understand the point that when using Traefik (or other Ingress controllers) we have just one Load-Balancer, the one of the Traefik in this case, and the other services will point to this one. Traefik then will redirect the traffic.
Related
I have set up a kubernetes cluster using kubeadm on a server, which is using an ingress controller (nginx) and this is working as intended. However, I used to deploy a nginx reverse proxy when I was using docker and to forward traffic to the containers. I have read that the ingress controller embarks a reverse proxy but I am not sure if it is sufficient and how to configure it (like IP ban when too many requests are sent in 1 s, ...).
I am aware that it can be done by modifying the port of the cluster and forwarding the traffic from the reverse proxy to the ingress controller but I don't know if it has any utility.
If you have more control over your inbound traffic, you can test multiple ingresses, not only Nginx. It will depend on the purpose of your requirement, although Nginx supports rate-limit. I suggest test others ingresses but try to install metal-lb firstly. So you can assign a specific Loadbalancer IP for each ingress.
I want to create a cluster of RESTful web APIs in AWS EKS and be able to access them through a single IP (allowing kubernetes to load balance requests to each). I have followed the procedure explained the this link and have set up an example nginx deployment as shown in the following image:
The problem is that when I access the example nginx deployment via 172.31.22.183 it works just fine, but when I try to use the cluster IP 10.100.145.181 it does not yield any response in such a way that it seems to be unreachable.
What's the purpose of that cluster ip then and how can I use it to achieve what I need?
What's the purpose of that cluster ip then and how can I use it to
achieve what I need?
ClusterIP is local IP that is used internally in the cluster, you can use it to access the application.
While i think Endpoint IP that you got, is might be external and you can access the application outside.
AWS EKS and be able to access them through a single IP (allowing
kubernetes to load balance requests to each)
For this best practice is to use the ingress, API gateway or service mesh.
Ingress is single point where all your request will be coming inside it will be load balancing and forwarding the traffic internally inside the cluster.
Consider ingress is like Loadbalancer single point to come inside the cluster.
Ingress : https://kubernetes.io/docs/concepts/services-networking/ingress/
AWS Example : https://aws.amazon.com/blogs/opensource/network-load-balancer-nginx-ingress-controller-eks/
ClusterIP is an IP that is only accessible inside the cluster. You cannot hit it from outside cluster unless you use kubectl port-forward
I've different deployments over different namespaces and I would like to expose some of them to the Internet, even if I don't have a static and public IP available.
The different services are deployed on Rancher k3s and every service which should be publicly accessible has an Ingress defined in the same namespace.
I was trying to follow Rancher - How to expose my services publicly?, but I didn't really get what I've to do and, moreover:
Why do we need to define a LoadBalancer? It seems to me that the IngressController used by k3s (Traefik?) already creates one. If this is a must (or a good way to go), how it should the service defined exactly?
I don't have any Rancher UI in my environment. Therefore, is there a way to achieve what described in that link in a declarative way?
Is there a way to use services like No-IP or FreeDNS for the final hostname?
If I get it right, you deployed Kubernetes manually on barebone/vms nodes and now you want to reach you deployments running inside that cluster.
There is two level of loadbalancing in this setup, the one managed by your ingress controller, sounds like it is traefik in your case, and it is recommanded to run a second L4 load balancer in front of your workers to reach the ingress pods that are usually deployed on multiple/all nodes. Traefik, or other lb controllers, will load balancer traffic inside the k8s cluster without issue even if you don't have a L4 load balancer, but it is not recommanded as if you loose this node, no traffic can reach the kubernetes cluster anymore. You "just" need to have your dns resolution pointing at your public ip and routed to one of your worker, or the LB in front of it. However, if you don't have a L4 LB, you'll need to have your ingress pods listening on ports 80 and/or 443.
Most things that you do in Rancher UI is just an easier way to see your k8s objects, all ingress configuration can be achieved via kubectl, k9s (strongly recommand thatone!), lens or other methods. However k8s objects are still k8s objects. In this case, you need to have your services exposed with ClusterIP that are then reachable by the ingress pods.
I've never used such a solution natively from k8s, but when I had too the internet router was able to do this part, once you're there, it is internal routing.
I hope this helps. Ingress can definitely be a tough one to grasp!
I have Kubernetes Cluster v1.10 Over Centos 7 Over OVH Cloud Provider's Servers .
As I knew OVH does not Provide Loadbalancer Component Directly to Kubernetes
And I want to buy Loadbalancer Component From OVH From this Link and connect to kubernetes Cluster .
Can I connect Loadbalancer to Kubernetes?
And is there any tutorial?
Thank You :D
Yes.
You can follow this guide from OVH in terms setting up your load balancer.
And in terms of Kubernetes you'd either want to create a Kubernetes Ingress exposed on a NodePort, this is a good tutorial for that, or you can also expose your services directly on a NodePort and point your load balancer's backend to all the nodes in your cluster on that specific NodePort.
I would also familiarize with the Services abstraction in Kubernetes.
Yes, you can.
How, on the other side, is not an obvious one. My suggestion would be to make it part of your kubernetes infra provisioning with terraform. Using https://www.terraform.io/docs/providers/ovh/r/iploadbalancing_tcp_farm_server.html you can manage endpoints for your loadbalancer based on instances / hosts provisioned either manually or with openstack provider. That's how I do it on our OVH Kube cluster.
I'm building a container cluster using CoreOs and Kubernetes on DigitalOcean, and I've seen that in order to expose a Pod to the world you have to create a Service with Type: LoadBalancer. I think this is the optimal solution so that you don't need to add external load balancer outside kubernetes like nginx or haproxy. I was wondering if it is possible to create this using DO's Floating IP.
Things have changed, DigitalOcean created their own cloud provider implementation as answered here and they are maintaining a Kubernetes "Cloud Controller Manager" implementation:
Kubernetes Cloud Controller Manager for DigitalOcean
Currently digitalocean-cloud-controller-manager implements:
nodecontroller - updates nodes with cloud provider specific labels and
addresses, also deletes kubernetes nodes when deleted on the cloud
provider.
servicecontroller - responsible for creating LoadBalancers
when a service of Type: LoadBalancer is created in Kubernetes.
To try it out clone the project on your master node.
Next get the token key from https://cloud.digitalocean.com/settings/api/tokens and run:
export DIGITALOCEAN_ACCESS_TOKEN=abc123abc123abc123
scripts/generate-secret.sh
kubectl apply -f do-cloud-controller-manager/releases/v0.1.6.yml
There more examples here
What will happen once you do the above? DO's cloud manager will create a load balancer (that has a failover mechanism out of the box, more on it in the load balancer's documentation
Things will change again soon as DigitalOcean are jumping on the Kubernetes bandwagon, check here and you will have a choice to let them manage your Kuberentes cluster instead of you worrying about a lot of the infrastructure (this is my understanding of the service, let's see how it works when it becomes available...)
The LoadBalancer type of service is implemented by adding code to the kubernetes master specific to each cloud provider. There isn't a cloud provider for Digital Ocean (supported cloud providers), so the LoadBalancer type will not be able to take advantage of Digital Ocean's Floating IPs.
Instead, you should consider using a NodePort service or attaching an ExternalIP to your service and mapping the exposed IP to a DO floating IP.
It is actually possible to expose a service through a floating ip. The only catch is that the external IP that you need to use is a little unintuitive.
From what it seems DO has some sort of overlay network for their Floating IP service. To get the actual IP you need to expose you need to ssh into your gateway droplet and find its anchor IP by hitting up the metadata service:
curl -s http://169.254.169.254/metadata/v1/interfaces/public/0/anchor_ipv4/address
and you will get something like
10.x.x.x
This is the address that you can use as an external ip in LoadBalancer type service in kubernetes.
Example:
kubectl expose rc my-nginx --port=80 --public-ip=10.x.x.x --type=LoadBalancer