Cannot access GKE with static external IP - gke-networking

I am trying to assign static external IP to the GKE LB.
apiVersion: v1
kind: Service
metadata:
name: onesg
labels:
app: onesg
spec:
selector:
app: onesg
ports:
- port: 80
targetPort: 5000
type: LoadBalancer
loadBalancerIP: "my regional IP"
But after deployment, I cannot access my app from the regional IP. Any idea?
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.104.0.1 <none> 443/TCP 23h
onesg LoadBalancer 10.104.15.191 my regional IP 80:31293/TCP 7m18s
If I use ephemeral IP assigned by GKE LB, I can access my app.

You have to check if your Service is actually pointing to the proper pods.
run the following
kubectl describe service onesg
in the output there should be a field called endpoints.
run this
kubectl get pods -o wide
and make sure the list of IP's in the endpoint field from the first command matches the IP of the pods from the second one
Next to troubleshoot you can try to make sure you app works, you can do that by using the kubectl port-forward command
https://kubernetes.io/docs/tasks/access-application-cluster/port-forward-access-application-cluster/

Related

Minikube expose service nginx proxy manager

I'm learning and trying to setup minikube in an ubuntu server to manage and deploy applications.
I'm using nginx proxy manager application to manage the proxy's in the server.
I've followed this tutorial to setup ingress with NGINX Ingress Controller, and everyhing works fine, when I run curl *minikube_ip*:service_port I get
Hello, world!
Version: 1.0.0
Hostname: web-746c8679d4-zhtll
Now, the problem is, I'm trying to expose this to the outside world by adding a proxy host in nginx proxy manager that proxies domain_name.com to the *minikube_ip*:service_port but it just keeps giving me 504 Gateway Time-out.
here's the ingress yaml
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
When I run kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d12h
web NodePort 10.104.186.135 <none> 8080:31806/TCP 2d12h
In my hosts file
*minikube_ip* hello-world.info
I suspect it might be related to the minikube docker container not being in the same network as the nginx proxy manager container, but I really don't know how to solve this, help pls
A NodePort type service can be accessed via the IP Address of the node(s) running in your cluster. Kubernetes will route the request to the proper pod based on the IP and port provided.
If you want to use a host name defined in an Ingress resource instead of the IP Address and port, change your service to type=ClusterIP.
Try running the following command to change your service to type ClusterIP:
kubectl patch svc web -p '{"spec": {"type": "ClusterIP"}}'
Wait for an EXTERNAL-IP to be assigned to the service, you can watch using kubectl get svc --watch
Update your hosts file with the EXTERNAL-IP value instead of the minikube_ip
Finally, try visiting hello-world.info in the browser

Kubernetes (docker-desktop) with multiple LoadBalancer services

Is it true that I cannot have two LoadBalancer services on a docker-desktop cluster (osx), because they would both use localhost (and all ports are forwarded)?
I created an example and the latter service is never assigned an external IP address but stays in state pending. However, the former is accessible on localhost.
> kubectl get all
NAME READY STATUS RESTARTS AGE
pod/whoami-deployment-9f9c86c4f-l5lkj 1/1 Running 0 28s
pod/whoareyou-deployment-b896ddb9c-lncdm 1/1 Running 0 27s
pod/whoareyou-deployment-b896ddb9c-s72sc 1/1 Running 0 27s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 95s
service/whoami-service LoadBalancer 10.97.171.139 localhost 80:30024/TCP 27s
service/whoareyou-service LoadBalancer 10.97.171.204 <pending> 80:32083/TCP 27s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/whoami-deployment 1/1 1 1 28s
deployment.apps/whoareyou-deployment 2/2 2 2 27s
NAME DESIRED CURRENT READY AGE
replicaset.apps/whoami-deployment-9f9c86c4f 1 1 1 28s
replicaset.apps/whoareyou-deployment-b896ddb9c 2 2 2 27s
Detailed state fo whoareyou-service:
kubectl describe service whoareyou-service
Name: whoareyou-service
Namespace: default
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"name":"whoareyou-service","namespace":"default"},"spec":{"ports":[{"name...
Selector: app=whoareyou
Type: LoadBalancer
IP: 10.106.5.8
Port: http 80/TCP
TargetPort: 80/TCP
NodePort: http 30333/TCP
Endpoints: 10.1.0.209:80,10.1.0.210:80
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
I decided to copy my comments, as they partially explain the problem, and make a Community Wiki answer out of them so it is more clearly seen and available for possible further edits by the Community:
It works probably exactly the same way as in Minikube. As docker-desktop is unable to provision real LoadBalancer it can still "simulate" creating Service of such type using NodePort (this can easily be seen from port range it uses). I'm pretty sure you cannot use same IP address as the ExternalIP of the LoadBalancer Service and if you create one more Service of such type, your docker-desktop has no other choice than to use your localhost one more time. As it is already used by one Service it cannot be used by another one and that's why it remains in a pending state.
Note that if you create real LoadBalancer in a cloud environment, each time new IP is provisioned and there is no situation that next LoadBalancer you create gets the same IP that is already used by the existing one. Apparently here it cannot use any other IP then one of localhost, and this one is already in use. Anyway I would recommend you to simply use NodePort if you want to expose your Deployment to the external world.
Think about using Ingress controller instead.
So basically, it's 3 steps after installing docker-desktop :
Wilcard Certificate locally
SSL certificate For local env
Install Ingress Controller
Detailed here: https://github.com/kubernetes-tn/guideline-kubernetes-enterprise/blob/master/general/desktop-env-setup.md
I came across this question while looking to set up a lightweight local environment with minimal dependencies.
I found that two LoadBalancer work on localhost when using different port numbers.
---
apiVersion: v1
kind: Service
metadata:
name: webapp-one-lb
spec:
ports:
- name: 8081-tcp
port: 8081
protocol: TCP
targetPort: 8080
selector:
name: webapp-one
type: LoadBalancer
status:
loadBalancer: {}
---
apiVersion: v1
kind: Service
metadata:
name: webapp-two-lb
spec:
ports:
- name: 8082-tcp
port: 8082
protocol: TCP
targetPort: 8080
selector:
name: webapp-two
type: LoadBalancer
status:
loadBalancer: {}
As others have said, Ingress is more flexible and allows for sub-domain and path based routing without having to worry about port conflicts, but it comes with an additional learning curve.

By kubernetes nodeport I can't get access to the application

I make configuration that my service is builded on 8080 port.
My docker image is also on 8080.
I put my ReplicaSet with configuration like this
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: my-app-backend-rs
spec:
containers:
- name: my-app-backend
image: go-my-app-backend
ports:
- containerPort: 8080
imagePullPolicy: Never
And finally I create service of type NodePort also on port 8080 with configuration like below:
apiVersion: v1
kind: Service
metadata:
labels:
app: my-app-backend-rs
name: my-app-backend-svc-nodeport
spec:
type: NodePort
ports:
- port: 8080
protocol: TCP
targetPort: 8080
selector:
app: my-app-backend
And after I put describe on NodePort I see that I should hit (e.g. curl http://127.0.0.1:31859/) to my app on address http://127.0.0.1:31859, but I have no response.
Type: NodePort
IP: 10.110.250.176
Port: <unset> 8080/TCP
TargetPort: 8080/TCP
NodePort: <unset> 31859/TCP
Endpoints: 172.17.0.6:8080
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
What am I not understanding and what am I doing wrong? Can anyone explain me that?
From your output,i'm seeing below endpoint is created.So it seems one pod is ready to serve for this nodeport service.So label is not an issue now.
Endpoints: 172.17.0.6:8080
First ensure you are able to access the app by running curl http://podhostname:8080 command, once you are login into the pod using kubectl exec -it podname sh(if curl is installed on image which running in that pod container).If not run curl ambassador container pods as sidecar and from that pod try to access the http://<>:8080 and ensure it is working.
Remember you can't access the nodeport service as localhost since it will be pointing to your master node,if you are running this command from master node.
You have to access this service by below methods.
<CLUSTERIP:PORT>---In you case:10.110.250.176:80
<1st node's IP>:31859
<2nd node's IP>:31859
I tried to use curl after kubectl exec -it podname sh
In this very example the double dash is missed in front of the sh command.
Please note that correct syntax can be checked anytime with the kubectl exec -h and shall be like:
kubectl exec (POD | TYPE/NAME) [-c CONTAINER] [flags] -- COMMAND [args...] [options]
if you have only one container per Pod it can be simplified to:
kubectl exec -it PODNAME -- COMMAND
The caveat of not specyfying the container is that in case of multiple containers on that Pod, you'll be conected to the first one :)
Example: kubectl exec -it pod/frontend-57gv5 -- curl localhost:80
I tried also hit on 10.110.250.176:80:31859 but this is incorrect I think. Sorry but I'm beginner at network stuff.
yes, that is not correct, as the value for :port occurs twice . In that example it is needed to hit 10.110.250.176:80 (as 10.110.250.176 is a "Cluster_IP" )
And after I put describe on NodePort I see that I should hit (e.g. curl http://127.0.0.1:31859/) to my app on address http://127.0.0.1:31859, but I have no response.
It depends on where you are going to run that command.
In this very case it is not clear what exactly you have put into ReplicaSet config (if Service's selector matches with ReplicaSet's labels), so let me explain "how this supposed to work".
Assuming we have the following ReplicaSet (the below example is slightly modified version of official documentation on topic ):
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: frontend-rs
labels:
app: guestbook
tier: frontend-meta
spec:
# modify replicas according to your case
replicas: 2
selector:
matchLabels:
tier: frontend-label
template:
metadata:
labels:
tier: frontend-label ## shall match spec.selector.matchLabels.tier
spec:
containers:
- name: php-redis
image: gcr.io/google_samples/gb-frontend:v3
And the following service:
apiVersion: v1
kind: Service
metadata:
labels:
app: frontend
name: frontend-svc-tier-nodeport
spec:
type: NodePort
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
tier: frontend-label ## shall match labels from ReplicaSet spec
We can create ReplicaSet (RS) and Service. As a result, we shall be able to see RS, Pods, Service and End Points:
kubectl get rs -o wide
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
frontend-rs 2 2 2 10m php-redis gcr.io/google_samples/gb-frontend:v3 tier=frontend-label
kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
frontend-rs-76sgd 1/1 Running 0 11m 10.12.0.31 gke-6v3n
frontend-rs-fxxq8 1/1 Running 0 11m 10.12.1.33 gke-m7z8
kubectl get svc -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
frontend-svc-tier-nodeport NodePort 10.0.5.10 <none> 80:32113/TCP 9m41s tier=frontend-label
kubectl get ep -o wide
NAME ENDPOINTS AGE
frontend-svc-tier-nodeport 10.12.0.31:80,10.12.1.33:80 10m
kubectl describe svc/frontend-svc-tier-nodeport
Selector: tier=frontend-label
Type: NodePort
IP: 10.0.5.10
Port: <unset> 80/TCP
TargetPort: 80/TCP
NodePort: <unset> 32113/TCP
Endpoints: 10.12.0.31:80,10.12.1.33:80
Important thing that we can see from my example is that Port was set 80:32113/TCP for the service we have created.
That shall allow us accessing "gb-frontend:v3" app in a few different ways:
from inside cluster: curl 10.0.5.10:80
(CLUSTER-IP:PORT) or curl frontend-svc-tier-nodeport:80
from external network (internet): curl PUBLIC_IP:32113
here PUBLIC_IP is the IP you can reach Node in your cluster. All the nodes in cluster are listening on a NodePort and forward requests according t the Service's selector.
from the Node : curl localhost:32113
Hope that helps.

Not able to access service from the public ip in kubernetes

I am using kubernetes and run one service. Service is running and is showing in service. But i am not able to access it from the public ip of the instance. Below is my deployment file.
apiVersion: v1
kind: Service
metadata:
name: apache-service
spec:
selector:
app: apache
ports:
- protocol: TCP
port: 80
targetPort: 80
type: NodePort
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
name: apache-deployment
spec:
selector:
matchLabels:
app: apache
replicas: 2 # tells deployment to run 2 pods matching the template
template:
metadata:
labels:
app: apache
spec:
containers:
- name: apache
image: mobingi/ubuntu-apache2-php7:7.2
ports:
- containerPort: 80
Here is my list of service.
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
apache-service NodePort 10.106.242.181 <none> 80:31807/TCP 9m5s
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 11m
But when i check the same service from the follwing telnet with the public ip of cluster and node. It is not responding.
telnet public-ip:31807
Any type of help will be appreciable.
What do you mean by cluster IP? Do you mean the node that acts as kunernetes master? It won't work if you use master IP. Because masters don't have deployments scheduled due to security concerns.
Exposing a service via nodeport means that the service listens to a particular port in each of the worker nodes. So you can access the kunernetes worker nodes with the nodeports and get response. However if you created the cluster using cloud providers like aws, the worker nodes security groups are secured. Probably, you need to edit the security groups of worker nodes to access the service.

Can't Access Kubernetes Service Exposed via NodePort

I'm using minikube to test kubernetes on latest MacOS.
Here are my relevant YAMLs:
namespace.yml
apiVersion: v1
kind: Namespace
metadata:
name: micro
labels:
name: micro
deployment.yml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: adderservice
spec:
replicas: 1
template:
metadata:
labels:
run: adderservice
spec:
containers:
- name: adderservice
image: jeromesoung/adderservice:0.0.1
ports:
- containerPort: 8080
service.yml
apiVersion: v1
kind: Service
metadata:
name: adderservice
labels:
run: adderservice
spec:
ports:
- port: 8080
name: main
protocol: TCP
targetPort: 8080
selector:
run: adderservice
type: NodePort
After running minikube start, the steps I took to deploy is as follows:
kubectl create -f namespace.yml to create the namespace
kubectl config set-context minikube --namespace=micro
kubectl create -f deployment.yml
kubectl create -f service.yml
Then, I get the NodeIP and NodePort with below commands:
kubectl get services to get the NodePort
$ kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
adderservice NodePort 10.99.155.255 <none> 8080:30981/TCP 21h
minikube ip to get the nodeIP
$ minikube ip
192.168.99.103
But when I do curl, I always get Connection Refused like this:
$ curl http://192.168.99.103:30981/add/1/2
curl: (7) Failed to connect to 192.168.99.103 port 30981: Connection refused
So I checked node, pod, deployment and endpoint as follows:
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
minikube Ready master 23h v1.13.3
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
adderservice-5b567df95f-9rrln 1/1 Running 0 23h
$ kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
adderservice 1 1 1 1 23h
$ kubectl get endpoints
NAME ENDPOINTS AGE
adderservice 172.17.0.5:8080 21h
I also checked service list from minikube with:
$ minikube service -n micro adderservice --url
http://192.168.99.103:30981
I've read many posts regarding accessing k8s service via NodePorts. To my knowledge, I should be able to access the app with no problem. The only thing I suspect is that I'm using a custom namespace. Will this cause the access issue?
I know namespace will change the DNS, so, to be complete, I ran below commands also:
$ kubectl exec -ti adderservice-5b567df95f-9rrln -- nslookup kubernetes.default
Server: 10.96.0.10
Address: 10.96.0.10#53
Name: kubernetes.default.svc.cluster.local
Address: 10.96.0.1
$ kubectl exec -ti adderservice-5b567df95f-9rrln -- nslookup kubernetes.micro
Server: 10.96.0.10
Address: 10.96.0.10#53
Non-authoritative answer:
Name: kubernetes.micro
Address: 198.105.244.130
Name: kubernetes.micro
Address: 104.239.207.44
Could anyone help me out? Thank you.
The error Connection Refused mostly means that the application inside the container does not accept requests on the targeted interface or not mapped through the expected ports.
Things you need to be aware of:
Make sure that your application bind to 0.0.0.0 so it can receive requests from outside the container either externally as in public or through other containers.
Make sure that your application is actually listening on the containerPort and targetPort as expect
In your case you have to make sure that ADDERSERVICE_SERVICE_HOST equals to 0.0.0.0 and ADDERSERVICE_SERVICE_PORT equals to 8080 which should be the same value as targetPort in service.yml and containerPort in deployment.yml
Not answering the question but if someone who googled comes here like me who faced the same issue. Here is my solution for the same problem.
My Mac System IP and minikube IP are different.
So localhost:port didn't work instead try getting IP
minikube ip
Later, use that IP:Port to access the app and it works.
Check if service is really listening on 8080.
Try telnet within the container.
telnet 127.0.0.1 8080
.
.
.
telnet 172.17.0.5 8080

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