Istio-ingress behind Google cloud Layer 7 load balancer - google-cloud-platform

Problem I am facing is that my istio-ingressgateway is working perfectly file at network layer load balancer(L4 loadbalancer or TCP load balancer) but when i connect istio-ingressgateway to Layer7 load balancer by attaching nodePort at backend service.after that http to https redirection not working properly its always give Response code 301 even when i request using https protocol.

I successfully configured the same architecture. Here the step to reproduce:
Deploy a GKE cluster. Either with Istio, or with istio installed afterward.
Get the Istio-ingressgateway nodeport for http:
kubectl -n istio-system get service istio-ingressgateway -o jsonpath='{.spec.ports[?(#.name=="http2")].port}'
Create a Global Loadbalancer
Create a backend service and select your cluster InstanceGroup.
Set the istio-ingressgateway nodeport as port
Create an health check, on the same nodeport value, in TCP mode
Configure your URL path
Validate and wait 5-10 minutes for letting the time to the health check to validate your configuration and to route the traffic
Now, you can reach your K8S cluster, through the Istio Nodeport with the global load balancer. Deploy a service on Istio, you could reach it through the Global Loadbalancer.

There is an issue on GitHub, Please check: https://github.com/istio/istio/issues/17980

Related

External DNS + Ingress Nginx + AWS ALB

I got the following setup:
Ingress-Nginx-Controller (serviceType "NodePort")
AWS-Load-Balancer-Controller
External-DNS
I am exposing the Ingress-Nginx-Controller via an Ingress, backed by the AWS Load Balancer Controller both public and private. I chose this route, since it was pretty easy to limit the inbound CIDRs. And nginx ingress cannot create an ALB but only Classic LB or NLB.
kubectl -n ingress-nginx get ing
NAME CLASS HOSTS ADDRESS PORTS AGE
alb-ingress-connect-nginx alb * xxxx.region.elb.amazonaws.com 80 2d8h
This ingress forwards all traffic to my nginx controller.
The service looks like
kubectl -n ingress-nginx get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ingress-nginx-controller NodePort a.b.c.d
I am trying to automatically setup dns records for my deployment via External-DNS. Therefore, I am creating an ingress for my deployment with ingress-class nginx and specified hostname.
Creating the records works, however it uses the IP of my ingress-nginx-controller service (a.b.c.d) instead of the loadbalancer's address.
Now my question: Is it possible to for external-dns to lookup the address of the nginx ingress or does this work only if the Nginx is exposed as service of type "LoadBalancer"?
Thanks for any help
I am able to figure this out by using --publish-status-address in nginx controller to point to ALB.
If you are using 2 ALBs (public and private), you need to create 2 nginx controllers with --publish-status-address points to each ALB. Also, remember to disable --publish-service parameter. And use different electionID for each controller if you have installed nginx controllers using Helm

Target health check fails - AWS Network Load Balancer

NOTE: I tried to include screenshots but stackoverflow does not allow me to add images with preview so I included them as links.
I deployed a web app on AWS using kOps.
I have two nodes and set up a Network Load Balancer.
The target group of the NLB has two nodes (each node is an instance made from the same template).
Load balancer actually seems to be working after checking ingress-nginx-controller logs.
The requests are being distributed over pods correctly. And I can access the service via ingress external address.
But when I go to AWS Console / Target Group, one of the two nodes is marked as and I am concerned with that.
Nodes are running correctly.
I tried to execute sh into nginx-controller and tried curl to both nodes with their internal IP address.
For the healthy node, I get nginx response and for the unhealthy node, it times out.
I do not know how nginx was installed on one of the nodes and not on the other one.
Could anybody let me know the possible reasons?
I had exactly the same problem before and this should be documented somewhere on AWS or Kubernetes. The answer is copied from AWS Premium Support
Short description
The NGINX Ingress Controller sets the spec.externalTrafficPolicy option to Local to preserve the client IP. Also, requests aren't routed to unhealthy worker nodes. The following troubleshooting implies that you don't need to maintain the cluster IP address or preserve the client IP address.
Resolution
If you check the ingress controller service you will see the External Traffic Policy field set to Local.
$ kubectl -n ingress-nginx describe svc ingress-nginx-controller
Output:
Name: ingress-nginx-controller
Namespace: ingress-nginx
...
External Traffic Policy: Local
...
This Local setting drops packets that are sent to Kubernetes nodes that aren't running instances of the NGINX Ingress Controller. Assign NGINX pods (from the Kubernetes website) to the nodes that you want to schedule the NGINX Ingress Controller on.
Update the pec.externalTrafficPolicy option to Cluster
$ kubectl -n ingress-nginx patch service ingress-nginx-controller -p '{"spec":{"externalTrafficPolicy":"Cluster"}}'
Output:
service/ingress-nginx-controller patched
By default, NodePort services perform source address translation (from the Kubernetes website). For NGINX, this means that the source IP of an HTTP request is always the IP address of the Kubernetes node that received the request. If you set a NodePort to the value of the externalTrafficPolicy field in the ingress-nginx service specification to Cluster, then you can't maintain the source IP address.

How does GCP internal load balancer + GKE service work? (It works, but I do not know why)

E.g. an istio service
istio-ingressgateway LoadBalancer 10.103.19.83 10.160.32.41 15021:30943/TCP,80:32609/TCP,443:30341/TCP,3306:30682/TCP,15443:30302/TCP
Which resulted in a TCP internal load balancer. The front end is ports 15021, 80, 443, 3306, and 15443.
The backend is basically the instance group of the cluster.
How does the load balancer know 443 at the front end will forward to 30341 at backend? As far as I know, TCP load balancer is doing port forwarding? How/Where does the magic happening
The LoadBalancer Service type is an extension of the NodePort type, which is an extension of the ClusterIP type. A nodePort just opens up a port in the range 30000-32767 on each worker node and uses a label selector to identify which Pods to send the traffic to.
This means that internal clients call the Service by using the internal IP address of a node along with the TCP port specified by nodePort. The request is forwarded to one of the member Pods on the TCP port specified by the targetPort field.
Here’s an example
When a Service is created in kubernetes, a corresponding Endpoints object is created along with it. It also applies to LoadBalancer service type.
If you create a simple nginx deployment e.g. by running:
kubectl apply -f https://k8s.io/examples/application/deployment.yaml
and then expose it as a LoadBalancer service:
kubectl apply -f https://k8s.io/examples/application/deployment.yaml
apart from the service itself, you will also see the lb-nginx Endpoints object. You can inspect its details:
kubectl get ep lb-nginx -o yaml
As you can see it keeps track of all exposed pods (being part of a Deployment in this case) so that corresponding iptables rules, which are responsible for forwarding the traffic to a particular pod, can be up-to-date all the time, even if number of them or their ip chages.
You can e.g. scale your deployment to 5 replicas:
kubectl scale deployment nginx-deployment --replicas=5
and inspect the Endpoints object again:
kubectl get ep lb-nginx -o yaml
and you will see that right after your 5 pods are up and running it immediately gets updated as well.
As you can see in subsets section of the yaml:
subsets:
- addresses:
- ip: 10.12.0.3
nodeName: gke-gke-default-pool-75259266-oauz
targetRef:
kind: Pod
name: nginx-deployment-66b6c48dd5-dw9mt
namespace: default
resourceVersion: "22394113"
uid: 8d7e1d3e-64e2-4891-b567-61ee48f61ed1
apart from the ip address of the Pod it maintains information about the node on which it is running.
Let's go back for a moment to the Service:
kubectl get svc lb-nginx -o yaml
As you can see LoadBalancer service apart from its external IP address has its ClusterIP as every other Service (well, almost every as headless services don't have ClusterIP):
spec:
clusterIP: 10.16.6.236
clusterIPs:
- 10.16.6.236
externalTrafficPolicy: Cluster
ports:
- nodePort: 31935
port: 80
protocol: TCP
targetPort: 80
So as you can imagine this external IP is somehow mapped to the cluster ip so it route the traffic further to the respective endpoints in the cluster. How exactly this mapping is done doesn't really matter as it is done by the cloud provider and such implementation details are not part of publicly shared knowledge. The only thing you need to know is that when your cloud provider provisions an external load balancer to satisfy your request defined in a Service of LoadBalancer type, apart from creating an external load balancer it takes care of the mapping between this external IP and some standard port assigned to it and a kubernetes service which has all the information needed to route the traffic further to the respective pods. In case you wonder how exactly this is done on GCP side i.e. mapping/binding between the external (or internal) loadbalancer and kubernetes LoadBalancer service, I'm affraid such implementation details are not publicly revealed.

Istio ingress gateway : domain name and port forwarding

I have set up an Istio service mesh. It works fine as I want so far. From outside I can only access with the port number like http://www.mytest.com:41333. What do I have to do to forward 80 to 41333 so that I can access it with http://www.mytest.com
Here is my Gateway :
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: mytest-gateway
spec:
selector:
istio: ingressgateway # use istio default controller
servers:
- port:
number: 80
name: http
protocol: HTTP
hosts:
- "www.mytest.com"
Not sure what to do...
I assume your istio ingress gateway service type is NodePort, if you istio ingress gateway is NodePort then you have to use http://www.mytest.com:41333.
If you want to use http://www.mytest.com then you would have to change it to LoadBalancer.
You can check if your istio ingress gateway is NodePort with
kubectl get svc -n istio-system
And check istio ingress gateway type.
NodePort: Exposes the Service on each Node's IP at a static port (the NodePort). A ClusterIP Service, to which the NodePort Service routes, is automatically created. You'll be able to contact the NodePort Service, from outside the cluster, by requesting NodeIP:NodePort.
LoadBalancer: Exposes the Service externally using a cloud provider's load balancer. NodePort and ClusterIP Services, to which the external load balancer routes, are automatically created.
As mentioned in istio documentation
If the EXTERNAL-IP value is (or perpetually ), your environment does not provide an external load balancer for the ingress gateway. In this case, you can access the gateway using the service’s node port.
If you use cloud like aws you can configure Istio with AWS Load Balancer with appropriate annotations.
On cloud providers which support external load balancers, setting the type field to LoadBalancer provisions a load balancer for your Service. The actual creation of the load balancer happens asynchronously, and information about the provisioned balancer is published in the Service's .status.loadBalancer
If it´s on premise, like minikube, then you could take a look at metalLB
MetalLB is a load-balancer implementation for bare metal Kubernetes clusters, using standard routing protocols.
Kubernetes does not offer an implementation of network load-balancers (Services of type LoadBalancer) for bare metal clusters. The implementations of Network LB that Kubernetes does ship with are all glue code that calls out to various IaaS platforms (GCP, AWS, Azure…). If you’re not running on a supported IaaS platform (GCP, AWS, Azure…), LoadBalancers will remain in the “pending” state indefinitely when created.
Bare metal cluster operators are left with two lesser tools to bring user traffic into their clusters, “NodePort” and “externalIPs” services. Both of these options have significant downsides for production use, which makes bare metal clusters second class citizens in the Kubernetes ecosystem.
MetalLB aims to redress this imbalance by offering a Network LB implementation that integrates with standard network equipment, so that external services on bare metal clusters also “just work” as much as possible.
You can read more about it in below link:
https://medium.com/#emirmujic/istio-and-metallb-on-minikube-242281b1134b

How to configure an AWS Elastic IP to point to an OpenShift Origin running pod?

We have set up OpenShift Origin on AWS using this handy guide. Our eventual
hope is to have some pods running REST or similar services that we can access
for development purposes. Thus, we don't need DNS or anything like that at this
point, just a public IP with open ports that points to one of our running pods.
Our first proof of concept is trying to get a jenkins (or even just httpd!) pod
that's running inside OpenShift to be exposed via an allocated Elastic IP.
I'm not a network engineer by any stretch, but I was able to successuflly get
an Elastic IP connected to one of my OpenShift "worker" instances, which I
tested by sshing to the public IP allocated to the Elastic IP. At this point
we're struggling to figure out how to make a pod visible that allocated Elastic IP,
owever. We've tried a kubernetes LoadBalancer service, a kubernetes Ingress,
and configuring an AWS Network Load Balancer, all without being able to
successfully connect to 18.2XX.YYY.ZZZ:8080 (my public IP).
The most promising success was using oc port-forward seemed to get at least part way
through, but frustratingly hangs without returning:
$ oc port-forward --loglevel=7 jenkins-2-c1hq2 8080 -n my-project
I0222 19:20:47.708145 73184 loader.go:354] Config loaded from file /home/username/.kube/config
I0222 19:20:47.708979 73184 round_trippers.go:383] GET https://ec2-18-2AA-BBB-CCC.us-east-2.compute.amazonaws.com:8443/api/v1/namespaces/my-project/pods/jenkins-2-c1hq2
....
I0222 19:20:47.758306 73184 round_trippers.go:390] Request Headers:
I0222 19:20:47.758311 73184 round_trippers.go:393] X-Stream-Protocol-Version: portforward.k8s.io
I0222 19:20:47.758316 73184 round_trippers.go:393] User-Agent: oc/v1.6.1+5115d708d7 (linux/amd64) kubernetes/fff65cf
I0222 19:20:47.758321 73184 round_trippers.go:393] Authorization: Bearer Pqg7xP_sawaeqB2ub17MyuWyFnwdFZC5Ny1f122iKh8
I0222 19:20:47.800941 73184 round_trippers.go:408] Response Status: 101 Switching Protocols in 42 milliseconds
I0222 19:20:47.800963 73184 round_trippers.go:408] Response Status: 101 Switching Protocols in 42 milliseconds
Forwarding from 127.0.0.1:8080 -> 8080
Forwarding from [::1]:8080 -> 8080
( oc port-forward hangs at this point and never returns)
We've found a lot of information about how to get this working under GKE, but
nothing that's really helpful for getting this working for OpenShift Origin on
AWS. Any ideas?
Update:
So we realized that sysdig.com's blog post on deploying OpenShift Origin on AWS was missing some key AWS setup information, so based on OpenShift Origin's Configuring AWS page, we set the following env variables and re-ran the ansible playbook:
$ export AWS_ACCESS_KEY_ID='AKIASTUFF'
$ export AWS_SECRET_ACCESS_KEY='STUFF'
$ export ec2_vpc_subnet='my_vpc_subnet'
$ ansible-playbook -c paramiko -i hosts openshift-ansible/playbooks/byo/config.yml --key-file ~/.ssh/my-aws-stack
I think this gets us closer, but creating a load-balancer service now gives us an always-pending IP:
$ oc get services
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
jenkins-lb 172.30.XX.YYY <pending> 8080:31338/TCP 12h
The section on AWS Applying Configuration Changes seems to imply I need to use AWS Instance IDs rather than hostnames to identify my nodes, but I tried this and OpenShift Origin fails to start if I use that method. Still at a loss.
It may not satisfy the "Elastic IP" part but how about using AWS cloud provider ELB to expose the IP/port to the pod via a service to the pod with LoadBalancer option?
Make sure to configure the AWS cloud provider for the cluster (References)
Create a svc to the pod(s) with type LoadBalancer.
For instance to expose a Dashboard via AWS ELB.
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard
namespace: kube-system
spec:
type: LoadBalancer <-----
ports:
- port: 443
targetPort: 8443
selector:
k8s-app: kubernetes-dashboard
Then the svc will be exposed as an ELB and the pod can be accessed via the ELB public DNS name a53e5811bf08011e7bae306bb783bb15-953748093.us-west-1.elb.amazonaws.com.
$ kubectl (oc) get svc kubernetes-dashboard -n kube-system -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
kubernetes-dashboard LoadBalancer 10.100.96.203 a53e5811bf08011e7bae306bb783bb15-953748093.us-west-1.elb.amazonaws.com 443:31636/TCP 16m k8s-app=kubernetes-dashboard
References
K8S AWS Cloud Provider Notes
Reference Architecture OpenShift Container Platform on Amazon Web Services
DEPLOYING OPENSHIFT CONTAINER PLATFORM 3.5 ON AMAZON WEB SERVICES
Configuring for AWS
Check this guide out: https://github.com/dwmkerr/terraform-aws-openshift
It's got some significant advantages vs. the one you referring to in your post. Additionally, it has a clear terraform spec that you can modify and reset to using an Elastic IP (haven't tried myself but should work).
Another way to "lock" your access to the installation is to re-code the assignment of the Public URL to the master instance in the terraform script, e.g., to a domain that you own (the default script sets it to an external IP-based value with "xip.io" added - works great for testing), then set up a basic ALB that forwards https 443 and 8443 to the master instance that the install creates (you can do it manually after the install is completed, also need a second dummy Subnet; dummy-up the healthcheck as well) and link the ALB to your domain via Route53. You can even use free Route53 wildcard certs with this approach.