I created a regional static IP in the same region of the cluster and I'm trying to use it with a LoadBalancer:
---
apiVersion: v1
kind: Service
metadata:
name: ambassador
spec:
type: LoadBalancer
externalTrafficPolicy: Local
ports:
- port: 80
targetPort: 8080
selector:
service: ambassador
loadBalancerIP: "x.x.x.x"
However, I don't know why I am getting this error:
Error creating load balancer (will retry): failed to ensure load balancer for service default/ambassador: requested ip "x.x.x.x" is neither static nor assigned to the LB
Edit: Problem solved but ..
When I created the static IP address, I used:
gcloud compute addresses create regional-ip --region europe-west1
I used this address with the Service.
It didn't work like I said.
However, when I created an external static regional IP using the web console, the IP worked fine with my Service and it was attached without problems.
My bet is that the source IP service is not exposed then. As the official docs say:
As of Kubernetes 1.5, packets sent to Services with Type=LoadBalancer are source NAT’d by default, because all schedulable Kubernetes nodes in the Ready state are eligible for loadbalanced traffic. So if packets arrive at a node without an endpoint, the system proxies it to a node with an endpoint, replacing the source IP on the packet with the IP of the node (as described in the previous section).
Try this command to expose the source IP service to the loadbalancer:
kubectl expose deployment <source-ip-app> --name=loadbalancer --port=80 --target-port=8080 --type=LoadBalancer
On this page, you will find more guidance and a number of diagnostic commands for sanity check.
https://kubernetes.io/docs/tutorials/services/source-ip/#source-ip-for-services-with-type-loadbalancer
Related
I am running
kubectl get nodes -o yaml | grep ExternalIP -C 1
But am not finding any ExternalIP. There are various comments showing up about problems with non-cloud setups.
I am following this doc https://kubernetes.io/docs/concepts/services-networking/connect-applications-service/
with microk8s on a desktop.
If you setup k8s cluster on Cloud, Kubernetes will auto detect ExternalIP for you. ExternalIP will be a Load Balance IP address. But if you setup it on premise or on your Desktop. You can set External IP address by deploy your Load Balance, such as MetaLB.
You can get it here
In short:
From my answer Kubernetes Ingress nginx on Minikube fails.
By default all solutions like minikube does not provide you
LoadBalancer. Cloud solutions like EKS, Google Cloud, Azure do it for
you automatically by spinning in the background separate LB. Thats why
you see Pending status.
In your case most probably right decision to look into MicroK8s Add ons. There is a Add on: MetalLB:
Thanks #Matt with his MetalLB external load balancer on docker-desktop community edition on Windows 10 single-node Kubernetes Infrastructure answer ans researched info.
MetalLB Loadbalancer is a network LB implementation that tries to
“just work” on bare metal clusters.
When you enable this add on you will be asked for an IP address pool
that MetalLB will hand out IPs from:
microk8s enable metallb
For load balancing in a MicroK8s cluster, MetalLB can make use of
Ingress to properly balance across the cluster ( make sure you have
also enabled ingress in MicroK8s first, with microk8s enable ingress).
To do this, it requires a service. A suitable ingress service is
defined here:
apiVersion: v1
kind: Service
metadata:
name: ingress
namespace: ingress
spec:
selector:
name: nginx-ingress-microk8s
type: LoadBalancer
# loadBalancerIP is optional. MetalLB will automatically allocate an IP
# from its pool if not specified. You can also specify one manually.
# loadBalancerIP: x.y.z.a
ports:
- name: http
protocol: TCP
port: 80
targetPort: 80
- name: https
protocol: TCP
port: 443
targetPort: 443
You can save this file as ingress-service.yaml and then apply it with:
microk8s kubectl apply -f ingress-service.yaml
Now there is a load-balancer which listens on an arbitrary IP and
directs traffic towards one of the listening ingress controllers.
We are running our ms as pod behind ALB ingress (ALB load balancer). My problem is that all of the HTTP request logs show the cluster IP address instead of the IPs of the HTTP clients. Is there any other way I can make kubernetes service to pass this info to my app servers to show the client ip address?
Even tried with java code usig get.remote.address function and still the same result.
I know there is a method "service.spec.externalTrafficPolicy" but this is only for GCE ad Not for AWS.
Any help!!!!!!
you can use Network Load Balancer with Kubernetes services, Client traffic first hits the kube-proxy on a cluster-assigned nodePort and is passed on to all the matching pods in the cluster.
When the spec.externalTrafficPolicy is set to the default value of Cluster, the incoming LoadBalancer traffic may be sent by the kube-proxy to pods on the node, or to pods on other nodes. With this configuration the client IP is sent to the kube-proxy, but when the packet arrives at the end pod, the client IP shows up as the local IP of the kube-proxy.
By changing the spec.externalTrafficPolicy to Local, the kube-proxy will correctly forward the source IP to the end pods, but will only send traffic to pods on the node that the kube-proxy itself is running on. Kube-proxy also opens another port for the NLB health check, so traffic is only directed to nodes that have pods matching the service selector.
apiVersion: v1
kind: Service
metadata:
name: nginx
namespace: default
labels:
app: nginx
annotations:
service.beta.kubernetes.io/aws-load-balancer-type: "nlb"
spec:
externalTrafficPolicy: Local
ports:
- name: http
port: 80
protocol: TCP
targetPort: 80
selector:
app: nginx
type: LoadBalancer
I was able to do this with the help of cloudfront.As our applications has high rate of data transfer so we used it in front of load balancer and in that i have also enabled the diffrent headers that Cloudfront Offers.
I'm building a K8 cluster for a school project.
It's bare metal and uses metallb as a loadbalancer.
Each service works in a separate pod:
Nginx
Wordpress
Phpmyadmin
Mysql (mariadb)
In the phpmyadmin file, I need to link my mysql server with something like this:
$cfg['Servers'][$i]['host'] = "mysql-server-name";
I've tried to use the node's IP:
kubectl get node -o=custom-columns='DATA:status.addresses[0].address' | sed -n 2p
adding the port :3306 but I realised that none of my services could be reached through the browser with this method.
For instance the node's Ip:5050 should redirect me to my wordpress but it doesn't.
Is there any way to get a single IP that I can use to make my pods communicate between them ?
I must add that each service works appart when I use the svc IP instead of the nodes.
Here's the configmap I use for metallb:
kind: ConfigMap
metadata:
namespace: metallb-system
name: config
data:
config: |
address-pools:
- name: default
protocol: layer2
addresses:
- 192.168.99.100-192.168.99.200
The reason the node IP doesn't expose your application to other apps is that the pods in the kubernetes cluster don't listen to the requests coming to the node by default. In other words, the port on the pod is not connected to the port on the node.
The service resource is what you need to make that connection.
Services have different types. A service of type cluster IP will assign an IP internal to the cluster to the app. If you don't want to access your mysql database directly from the internet, this is what you would want.
Here is an example service of type cluster IP for your project.
apiVersion: v1
kind: Service
metadata:
name: mysql-service
namespace: metallb-system
spec:
selector:
app: Mysql
ports:
- protocol: TCP
port: 80
targetPort: 3306
Selector selects pods that carry the label app=mysql.
Port is the port that the service will listen to.
TargetPort is the port that mysql is listening to.
When you create the service you can find it's IP by running this command
kubectl get services -n metallb-system
Under CLUSTER-IP column note the IP of the service you created.
So in this case, if mysql is listening to 3306, you can reach it through this service on the service IP on port 80.
If you want to expose your wordpress app to the internet, use either the NodePort or LoadBalancer service types. Here is the reference for service types.
I know a scenario of kubernetes headless service with selector.
But what’s the usage scenario of kubernetes headless service without selector?
Aliasing external services into the cluster DNS.
Services without selectors are used if you want to have an external database cluster in production, but in your test environment you use your own databases, to point your Service to a Service in a different Namespace or on another cluster, when you are migrating a workload to Kubernetes.
Service without selectors are often used to alias external services into the cluster DNS.
Here ia an example of service without selector:
apiVersion: v1
kind: Service
metadata:
name: example-service
spec:
ports:
- protocol: TCP
port: 80
targetPort: 9376
This Service has no selector, the corresponding Endpoint object is not created automatically. You can manually map the Service to the network address and port where it’s running, by adding an Endpoint object manually:
apiVersion: v1
kind: Endpoints
metadata:
name: example-service
subsets:
- addresses:
- ip: 192.0.2.42
ports:
- port: 9376
If you have more that one IP address for redundancy, you can repeat them in the addresses array. Once the endpoints are populated, the load balancer will start redirecting traffic from your Kubernetes service to the IP addresses,
Note: The endpoint IPs must not be: loopback (127.0.0.0/8 for IPv4, ::1/128 for IPv6), or link-local (169.254.0.0/16 and 224.0.0.0/24 for IPv4, fe80::/64 for IPv6). Endpoint IP addresses cannot be the cluster IPs of other Kubernetes Services, because kube-proxy doesn’t support virtual IPs as a destination.
You can access a Service without a selector the same as if it had a selector.
Take a look: services-without-selector, example-service-without-selector.
i have a application ( Let's say Integration-protocol-api)
and this application want to talk to other application, but this application located on another Network (Let's call it Another-Integration-Protocol)
And problem is, on another-integration-protocol side the whitelist exist, which allow to connect to it, only from selected ip addresses.
But my integration-protocol-api is Dockerized and running on Kubernetes cluster, so ip address is changing everyime when i restart my pod.
how can i assign the Public and Static ip to my Kubernetes Pod?
But my integration-protocol-api is Dockerized and running on Kubernetes cluster, so ip address is changing everyime when i restart my pod. how can i assign the Public and Static ip to my Kubernetes Pod
There are several approaches, depending on your actual setup/needs and I'll try to give some options here:
Tie pod to specific node and expose that node's IP address through service. This would be something along those lines:
# Quick deployment/pod manifest node selector (affinity is better)
...
spec:
nodeSelector:
kubernetes.io/hostname: my-node-name
...
# Service manifest
apiVersion: v1
kind: Service
metadata:
name: svc-myservice
labels:
app: myapp
tier: frontend
spec:
selector:
app: myapp
tier: frontend
ports:
- name: tcpserviceport
protocol: TCP
port: 8080
targetPort: 80
externalIPs:
- 111.222.222.111
Pod should be in same namespace, tied to that node via either node selector or affinity rules and have same labels as in selector for service to pick it up. IP address of cluster node with name my-node-name should be 111.222.222.111 in this example, and it would be accessible through port 8080 and that ip address.
If applicable, expose service through ingress and whitelist ingress public ip only. Depending on your namespace separation you'll reference your pod (wherever it might run) in ingress through corresponding service using either service name (in namespace scope) or FQDN such as:
<service-name>.<namespace-name>.svc.cluster.local
Here is good overview of some methods to make it more illustrative from kubernetes docs: https://kubernetes.io/docs/tutorials/kubernetes-basics/expose-intro/
A pod makes any request with it's node IP address as source. So you could whitelist your cluster nodes' IP addresses, and it should work.