I used the below command to build my spring boot application for deployment in google cloud.
mvn clean install && docker build -t eu.gcr.io/XXX/demo .
gcloud builds submit --tag eu.gcr.io/XXX/demo
kubectl run demo-server --image eu.gcr.io/XXX/demo
kubectl expose deployment demo-server --type=LoadBalancer –port=8080
And I can access my application externally. I can delete and redeploy my application using:
kubectl delete deployment demo-server
kubectl run demo-server --image eu.gcr.io/XXX/demo
It is all working fine, but when I tried to expose the same application on different port say 8081, it failed to complain Error from server (AlreadyExists): services "demo-server" already exists
How can I change the service port?
I resolved it by
kubectl get services
kubectl delete services demo-server
I was deleting deployment but service was still available
Related
In kubernetes I have a command as
kubectl create deployment nginx --image=ewoutp/docker-nginx-curl -n web
What should I run if I want to create this inside openshift cluster
I tried this
oc create deployment nginx --image=ewoutp/docker-nginx-curl -n web
I am getting error as error:
no matches for extensions/, Kind=Deployment
Can someone help me?
It might indicate that your openshift cluster is not running. Check oc status to view status of your current project. If it is not running you should create new project.
If you cluster is running you can run oc create deployment nginx --image=ewoutp/docker-nginx-curl -n web -o yaml to verify if apiVersion is correct. Currently used version is apps/v1. If it is incorrect you can save it to file and edit to match current version.
I create a pod to test my service in kubernetes. But i didn't get anythings. Here is my command
kubectl run --generator=run-pod/v1 nginx-resolver --image=nginx
kubectl expose pod nginx-resolver --name=nginx-resolver-service --port=80 --target-port=80 --type=ClusterIP
kubectl run --generator=run-pod/v1 test-nslookup --image=busybox:1.28 --rm -it -- nslookup nginx-resolver-service
Please help me explain why. Thanks
Run the following command and get things what you are thinking wrong about this cmd.
$ kubectl run --help
Create and run a particular image, possibly replicated.
Creates a deployment or job to manage the created container(s).
Examples:
# Start a single instance of nginx.
kubectl run nginx --image=nginx
# Start a single instance of hazelcast and let the container expose port 5701 .
kubectl run hazelcast --image=hazelcast --port=5701
...
So, kubectl run cmd creates a deployment or a job
If it is a deployment, it creates (a) first, a replicaset, (b) then Pod(s).
If it is a job, it creates a Pod.
But you are trying to expose a Pod which name is not the correct one. You can see the name of the Pod that is/are created by the cmd kubectl run.
$ kubectl get pods --namespace=<namespace> | grep "nginx-resolver"
$ kubectl get pods --namespace=<namespace> | grep "test-nslookup"
Then use those names to expose Pod.
You can optionally expose your Deployment. To do so, see the help of $ kubectl expose deployment --help. Run:
$ kubectl expose deployment --help
Expose a resource as a new Kubernetes service.
Looks up a deployment, service, replica set, replication controller or pod by name and uses the selector for that
resource as the selector for a new service on the specified port. A deployment or replica set will be exposed as a
service only if its selector is convertible to a selector that service supports, i.e. when the selector contains only
the matchLabels component. Note that if no port is specified via --port and the exposed resource has multiple ports, all
will be re-used by the new service. Also if no labels are specified, the new service will re-use the labels from the
resource it exposes.
Possible resources include (case insensitive):
pod (po), service (svc), replicationcontroller (rc), deployment (deploy), replicaset (rs)
Examples:
...
# Create a service for an nginx deployment, which serves on port 80 and connects to the containers on port 8000.
kubectl expose deployment nginx --port=80 --target-port=8000
...
If you want to see the log interactively, you need to set the --restart option of your test-nslookup pod to Never or OnFailure. Otherwise, kubernetes will just restart your pod indefinitely and you won't see anything.
So your last command should be :
kubectl run --generator=run-pod/v1 test-nslookup --image=busybox:1.28 -it --restart=OnFailure -- nslookup nginx-resolver-service
Why ?
Probably because of this issue.
It seems to have a delay of 5s before kubectl run actually print something.
So in order to do it without changing the restart option, you'll need to change your command like this (beware of the sleep 7, so you'll have to wait 7seconds before seeing the logs) :
kubectl run --generator=run-pod/v1 test-nslookup --image=busybox:1.28 -it --rm -- sh -c 'sleep 7; nslookup nginx-resolver-service'
See below service is running:
and Below error i am getting while trying to access it:
Kubectl get pods:
Yaml files:
Service:
Deployment:
Check pod status if it's running or not.
Also, you can try with port-forwarding to POD
kubectl port-forward <POD name> 8086:8086 & open localhost:8086
new to calico, trying to secure Kubernetes cluster using calico.
I have installed kubectl using command curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl referring the docs here.
I tried to install Calico Kubernetes NetworkPolicy using kubectl commands by refereeing here : kubectl create ns policy-demo creating namespace
This is then followed by creating nginx pod and services:
kubectl run --namespace=policy-demo nginx --replicas=2 --image=nginx
kubectl expose --namespace=policy-demo deployment nginx --port=80
Now, I want to uninstall and remove the policy-demo and namespace from the system.
Is there is ant way I can do it and remove this from my system using command?
How can I uninstall and remove the policy-demo?
There is a simple way of doing it.
You just need to use kubectl delete ns policy-demo to remove, clean and will delete the policy-demo namespace from the system using kubectl command.
It is already mentioned here in the end of the document: https://docs.projectcalico.org/v2.6/getting-started/kubernetes/tutorials/simple-policy
I've used the following command to update the image run in a deployment:
kubectl --cluster websites --namespace production set image
deployment/mobile-web mobile-web=eu.gcr.io/websites/mobile-web:0.23
This worked well until I created a staging namespace mirroring the production environment. In other words the deployment mobile-web exists both in the production and staging namespace. Now I get the error:
Error from server: the server could not find the requested resource
(get deployments.extensions mobile-web)
What am I missing here? Or is the only way to update using a yaml- or JSON-file, which means a bit more work on the CI/CD pipeline? I've tried setting the namespace with:
kubectl config set-context production --namespace=production --cluster=websites
but to no avail.
The solution for my concern was to kill the current proxy and get new credentials and start the proxy again:
gcloud container clusters get-credentials websites
kubectl proxy --port=8080
Now either commands work as expected:
kubectl get deployment mobile-web --namespace=production
kubectl get deployment mobile-web --namespace=staging
However it doesn't explain why it stopped working in the first place.