Reserve static IP address for k8s external service - kubernetes

I want to reserve static IP address for my k8s exposed service.
If I am not mistaken when I expose the k8s service it gets the random public IP address. I redeploy my app often and the IP changes.
But I want to get permanent public IP address.
My task is to get my application via permanent IP address (or DNS-name).

This is cloud provider specific, but from the tag on your question it appears you are using Google Cloud Platform's Kubernetes Engine (GKE). My answer is specific for this situation.
From the Setting up HTTP Load Balancing with Ingress tutorial:
gcloud compute addresses create web-static-ip --global
And in your Ingress manifest:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: basic-ingress
annotations:
kubernetes.io/ingress.global-static-ip-name: "web-static-ip"
spec:
backend:
serviceName: web
servicePort: 8080
You can do something similar if you using Service instead of Ingress:
apiVersion: v1
kind: Service
metadata:
name: helloweb
labels:
app: hello
spec:
type: LoadBalancer
loadBalancerIP: "web-static-ip"
selector:
app: hello
tier: web
ports:
- port: 80
targetPort: 8080

Related

Kubernetes Ingress - how to access my service on my computer?

I have the following template, with a deployment, a service and an Ingress. I ran minikube addons enable ingress locally to add an ingress controller before.
apiVersion: apps/v1
kind: Deployment
metadata:
name: fastapi
labels:
app: fastapi
spec:
replicas: 1
selector:
matchLabels:
app: fastapi
template:
metadata:
labels:
app: fastapi
spec:
containers:
- name: fastapi
image: datamastery/fastapi
ports:
- containerPort: 3000
---
apiVersion: v1
kind: Service
metadata:
name: fastapi-service
spec:
selector:
app: fastapi
type: LoadBalancer
ports:
- protocol: TCP
port: 5000
targetPort: 3000
nodePort: 30002
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: dashboard-ingress
namespace: kubernetes-dashboard
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
rules:
- host: datamastery.com
http:
paths:
- path: /
pathType: Exact
backend:
service:
name: fastapi-service
port:
number: 3000
When I run kubectl get servicesI get:
fastapi-service LoadBalancer 10.108.5.228 <pending> 5000:30002/TCP 5d22h
I my etc/hosts/ file I added the following:
10.108.5.228 datamastery.com
Normally I would expect now to be able to open my service in the browser, but nothing happens. What did I do wrong? Did I miss something in the template? Is the IP wrong? Something in the hosts file?
Thank you!
fastapi-service LoadBalancer 10.108.5.228 5000:30002/TCP 5d22h
10.108.5.228 is an address within your SDN. Only members of your SDN can reach this address, it is unlikely your workstation would have a route sending this trafic to one of your Kubernetes nodes.
<pending> means your cluster is not integrated with a cloud provider with LoadBalancer capabilities. When in doubt: you should use ClusterIP as your service type. LoadBalancer only makes sense in specific cases. While setting a nodePort as you did is also not required (would make sense with a NodePort service, which is as well useful in few use cases, though should not be used otherwise).
You did create an Ingress. If you have an Ingress Controller, you want to connect to that ip/port. The Host header would tell your ingress controller where to route this, within your SDN.
I believe what you are doing here is trying to combine two different things.
NodePort is only sufficient if you have only one node OR you really control where your service pods getting deployed. Otherwise it is not suitable to use the node IP to access services.
To overcome this issue we usually use ingress as a service proxy. Incoming traffic will be routed to the correct service pods depending on the URL and port. Ingress also manages the SSL termination. So basically this is your first "load balancer" as ingress assigned traffic to services across nodes and pods.
In production environment you deploy the ingress controller with the type: Loadbalancer in the kube-system namespace, example for Nginx-ingress:
apiVersion: v1
kind: Service
metadata:
name: nginx-ingress
namespace: kube-system
labels:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
spec:
type: LoadBalancer
ports:
- port: 80
name: http
targetPort: 80
- port: 443
name: https
targetPort: 443
selector:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
This would spin up a cloud load balancer of your provider and link it to the ingress service in your cluster. So basically now you would have a real load balancer in place balancing traffic between your nodes and ingress routes them to your services and services to your pods.
Back to your question:
In your config files you try to spin up a service with the type: LoadBalancer. This would skip the ingress part and spin up a second cloud load balancer from your provider dedicated for this single service.
You have to remove the type (and nodePort) to use default ClusterIP for your service.
apiVersion: v1
kind: Service
metadata:
name: fastapi-service
spec:
selector:
app: fastapi
ports:
- protocol: TCP
port: 3000
targetPort: 3000
In addition you have mentioned a wrong port. Your ingress object points on port 3000. You Service object on port 5000. So we also change this.
With this config your traffic on the FQDN is routed to ingress, to ClusterIP service on port 3000 to your pods.

Connect two pods to the same external access point

I have two pods (deployments) running on minikube. Each pod has the same port exposed (say 8081), but use different images. Now I want to configure so that I can access either of the pods using the same external URL, in a load balanced way. So what I tried to do is put same matching label in both pods and map them to same service and then expose through NodePort. Example:
#pod1.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: dep1
labels:
apps: dep1
tier: cloud
spec:
template:
metadata:
name: dep1-pod
labels:
app: deployment1
spec:
containers:
- name: cont1
image: cont1
ports:
- containerPort: 8081
selector:
matchLabels:
app:deployment1
Now second pod
#pod2.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: dep2
labels:
apps: dep2
tier: cloud
spec:
template:
metadata:
name: dep2-pod
labels:
app: deployment1
spec:
containers:
- name: cont2
image: cont2
ports:
- containerPort: 8081
selector:
matchLabels:
app:deployment1
Now the service:
#service.yaml
apiVersion: v1
kind: Service
metadata:
name: service1
spec:
type: NodePort
ports:
- port: 8081
targetPort: 8081
nodePort: 30169
selector:
app: deployment1
Now this does not work as intended as it refuses to connect to my IP:30169. However, I can connect if only one of the pods are deployed.
Now I know I can achieve this functionality using replicas and just one image, but in this case, I want to do this using 2 images. Any help is much appreciated.
You can use Ingress to achieve it.
Ingress exposes HTTP and HTTPS routes from outside the cluster to services within the cluster. Traffic routing is controlled by rules defined on the Ingress resource.
An Ingress may be configured to give Services externally-reachable URLs, load balance traffic, terminate SSL / TLS, and offer name-based virtual hosting.
An Ingress controller is responsible for fulfilling the Ingress, usually with a load balancer, though it may also configure your edge router or additional frontends to help handle the traffic.
An Ingress does not expose arbitrary ports or protocols. Exposing services other than HTTP and HTTPS to the internet typically uses a service of type Service.Type=NodePort or Service.Type=LoadBalancer.
In your situation Ingress will forward traffic to your services using the same URL. It depends which path you type: URL for first Pod and URL/v2 for second Pod. Of course you can change /v2 to something else.
On the beginning you need enable Ingress on minikube. You can do it using a command below. You can red more about it here
minikube addons enable ingress
Next step you need create a Ingress using a yaml file. Here is an example how to do it step by step.
Yaml file of Ingress looks as below.
As you can see in this configuration, you can access to one Pod using URL and it will forward traffic to first service attached to the first Pod. For the second Pod using URL/v2 it will forward traffic to second service on attached to the second Pod.
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: example-ingress
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
rules:
- host: hello-world.info
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: web
port:
number: 8080
- path: /v2
pathType: Prefix
backend:
service:
name: web2
port:
number: 8080

K8s service LB to external services w/ nginx-ingress controller

Is it possible to configure k8s nginx-ingress as a LB to have a K8s Service actively connect to external backend hosted on external hosts/ports (where one will be enabled at a time, connecting back to the cluster service)?
Similar to envoy proxy? This is on vanilla K8s, on-prem.
So rather than balance load from
client -> cluster -> service.
I am looking for
service -> nginx-ingress -> external-backend.
Define a Kubernetes Service with no selector. Then you need to define a Endpoint. You can put the IP and port in the Endpoint. Normally you do not define Endpoints for Services but because the Service will not have a Selector you will need to provide an Endpoint with the same name as the Service.
Then you point the Ingress to the Service.
Here's an example that exposes an Ingress on the cluster and sends the traffic to 192.168.88.1 on TCP 8081.
apiVersion: v1
kind: Service
metadata:
name: router
namespace: default
spec:
ports:
- protocol: TCP
port: 80
targetPort: 8081
---
apiVersion: v1
kind: Endpoints
metadata:
name: router
namespace: default
subsets:
- addresses:
- ip: 192.168.88.1
- ip: 192.168.88.2 # As per question below
ports:
- port: 8081
---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: router
namespace: default
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
rules:
- host: my-router.domain.com
http:
paths:
- path: /
backend:
serviceName: router
servicePort: 80
While defining ingress use nginx.ingress.kubernetes.io/configuration-snippet annotation. Enable also proxy protocol using use-proxy-protocol: "true".
Using this annotation you can add additional configuration to the NGINX location.
Please take a look: ingress-nginx-issue, advanced-configuration-with-annotations.

Nginx Ingress Failing to Serve

I am new to k8s
I have a deployment file that goes below
apiVersion: apps/v1
kind: Deployment
metadata:
name: jenkins-deployment
spec:
replicas: 3
selector:
matchLabels:
component: web
template:
metadata:
labels:
component: web
spec:
containers:
- name: jenkins
image: jenkins
ports:
- containerPort: 8080
- containerPort: 50000
My Service File is as following:
apiVersion: v1
kind: Service
metadata:
name: jenkins-svc
spec:
type: ClusterIP
ports:
- port: 80
targetPort: 8080
name: http
selector:
component: web
My Ingress File is
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: jenkins-ingress
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- host: jenkins.xyz.com
http:
paths:
- path: /
backend:
serviceName: jenkins-svc
servicePort: 80
I am using the nginx ingress project and my cluster is created using kubeadm with 3 nodes
nginx ingress
I first ran the mandatory command
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/mandatory.yaml
when I tried hitting jenkins.xyz.com it didn't work
when I tried the command
kubectl get ing
the ing resource doesnt get an IP address assigned to it
The ingress resource is nothing but the configuration of a reverse proxy (the Ingress controller).
It is normal that the Ingress doesn't get an IP address assigned.
What you need to do is connect to your ingress controller instance(s).
In order to do so, you need to understand how they're exposed in your cluster.
Considering the YAML you claim you used to get the ingress controller running, there is no sign of exposition to the outside network.
You need at least to define a Service to expose your controller (might be a load balancer if the provider where you put your cluster supports it), you can use HostNetwork: true or a NodePort.
To use the latest option (NodePort) you could apply this YAML:
https://github.com/kubernetes/ingress-nginx/blob/master/deploy/static/provider/baremetal/service-nodeport.yaml
I suggest you read the Ingress documentation page to get a clearer idea about how all this stuff works.
https://kubernetes.io/docs/concepts/services-networking/ingress/
In order to access you local Kubernetes Cluster PODs a NodePort needs to be created. The NodePort will publish your service in every node using using its public IP and a port. Then you can access the service using any of the cluster IPs and the assigned port.
Defining a NodePort in Kubernetes:
apiVersion: v1
kind: Service
metadata:
name: nginx-service-np
labels:
name: nginx-service-np
spec:
type: NodePort
ports:
- port: 8082 # Cluster IP, i.e. http://10.103.75.9:8082
targetPort: 8080 # Application port
nodePort: 30000 # (EXTERNAL-IP VirtualBox IPs) i.e. http://192.168.50.11:30000/ http://192.168.50.12:30000/ http://192.168.50.13:30000/
protocol: TCP
name: http
selector:
app: nginx
See a full example with source code at Building a Kubernetes Cluster with Vagrant and Ansible (without Minikube).
The nginx ingress controller can be replaced also with Istio if you want to benefit from a service mesh architecture for:
Load Balance traffic, external o internal
Control failures, retries, routing
Apply limits and monitor network traffic between services
Secure communication
See Installing Istio in Kubernetes under VirtualBox (without Minikube).

How to Kubernetes Angular.js service request backendapi service

----------------------- Thats backandapi Service-----------------------
apiVersion: v1
kind: Service
metadata:
name: backandapi-service
namespace: crm
labels:
app: backandapi-service
spec:
type: LoadBalancer
ports:
- port: 80
targetPort: 80
selector:
app: backandapi
And, Angular.js request to this service but Service changing ip adress.
How to access Services external endpoint from env or similar.
Depending on what provides your loadbalancer you will see different ways of doing this. Said short kubectl describe <your_svc> would return something like LoadBalancer Ingress firld, that on aws will look similar to blablabla-123123.eu-west-1.elb.amazonaws.com which you can use to access regardless of underlying IP