I'm trying to setup a kubernetes cluster with kubeadm and vagrant. I faced an error during installing nginx ingress controller was timeout when the pods is trying to retrieve the configmap through kubernetes API. I have looked around and trying to apply their solution, still no luck, this is the reason I come out with this post.
Environment:
I'm using vagrant to setup 2 nodes with ubuntu/xenial image.
kmaster
-------------------------------------------
network:
Adapter1: NAT
Adapter2: HostOnly-network, IP:192.168.2.71
kworker1
-------------------------------------------
network:
Adapter1: NAT
Adapter2: HostOnly-network, IP:192.168.2.72
I followed the kubeadm to setup the cluster
[Setup kubernetes with kubeadm]
And my kube cluster init command as below:
kubeadm init --pod-network-cidr=192.168.0.0/16 --apiserver-advertise-address=192.168.2.71
and apply calico network plugin policy:
kubectl apply -f \
https://docs.projectcalico.org/v3.4/getting-started/kubernetes/installation/hosted/etcd.yaml
kubectl apply -f \
https://docs.projectcalico.org/v3.4/getting-started/kubernetes/installation/hosted/calico.yaml
(Calico is a plugin I currently successful installed with, I will come out another post for flannel plugin which the plugin unable to access the service)
I'm using helm to install ingress controller followed the tutorial
https://kubernetes.github.io/ingress-nginx/deploy/
That's the error occurred once I applied helm deploy command when I describe the pod
Appreciate someone can help, as I know the reason was the pod unable to access kubernetes API. But not this already should enable by kubernetes by default?
My kubesystem pods status as below:
Another solution provided from kubernetes official website:
1) install kube-proxy with sidecar, I still new with kubernetes and I'm looking for example how to install kube-proxy with sidecar. Appreciate if someone could provide an example.
2) use client-go, I'm very confuse when I read this post, it seems that using go command to pull the go script, and I have no clue how's it working with kubernetes pods.
You guys are right, I have tested with digital ocean's droplet and it works as expected, I hit another error is "forbidden, user service account not permitted". Look like the pods is able to access the kubernetes api already. I also tested install istio which I encountered the same issue before, and now it worked in digital ocean droplet.
Thank you guys.
Related
I am new to Kubernetes. I am trying to deploy an app on Kubernetes. I am working on ubuntu. I have tried using both docker and VirtualBox as the driver. The problem is that when I expose the service, I am not able to access the service from minikubeurl:port. I searched the internet and discovered that it is something with nested virtualization. I have tried multiple solutions but they didn't work for me. Can anyone help me with this and let me know if I am missing some basics?
I am using the following commands for the process:
minikube start --driver=docker --force
k create deployment k8 --image=bstashchuk/k8s-web-hello
k scale deployments k8 --replicas=5
k expose deployment k8 --type=NodePort --port 3000
k get svc
When I am trying to hit http://10.110.45.252:30701/ in the browser the page is not loading. However, it is showing content when I did curl in minikube ssh.
Please Help.
I am learning kubernetes and minikube, and I am following this tutorial:
https://minikube.sigs.k8s.io/docs/handbook/accessing/
But I am running into a problem, I am not able to load the exposed service. Here are the steps I make:
minikube start
The cluster info returns
Kubernetes control plane is running at https://127.0.0.1:50121
CoreDNS is running at https://127.0.0.1:50121/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
Then I am creating a deployment
kubectl create deployment hello-minikube1 --image=k8s.gcr.io/echoserver:1.4
and exposing it as a service
kubectl expose deployment hello-minikube1 --type=NodePort --port=8080
When I list the services, I dont have a url:
minikube service list
NAMESPACE
NAME
TARGET PORT
URL
default
hello-minikube1
8080
and when I try to get the url, I am not getting it, seems to be empty
minikube service hello-minikube1 --url
This is the response (first line is empty):
🏃 Starting tunnel for service hello-minikube2.
❗ Because you are using a Docker driver on darwin, the terminal needs to be open to run it.
Why I am not getting the url and cannot connect to it? What did I miss?
Thanks!
Please use minikube ip command to get the IP of minikube and then use port number with it.
Also, refer below link:
https://minikube.sigs.k8s.io/docs/handbook/accessing/#:~:text=minikube%20tunnel%20runs%20as%20a,on%20the%20host%20operating%20system.
As per this issue,the docker driver, which needs an active terminal session. Who are using macOS to use docker driver by default a few releases ago, if no local configuration is found. I believe you can get your original behavior by using the hyperkit driver on macOS:
minikube start --driver=hyperkit
You can also set it to the default using:
minikube config set driver hyperkit
This will help you to solve your issue.
As the question shows, I have very low knowledge about kubernetes. Following a tutorial, I made a Kubernetes cluster to run a web app on a local server using Minikube. I have applied the kubernetes components and they are running but the Web-Server does not respond to HTTP requests. My problem is that all the system that I have created is like a black box for me and I have literally no idea how to open it and see where the problem is. Can you explain how I can debug such implementaions in a wise way. Thanks.
use a tool like https://github.com/kubernetes/kubernetes-dashboard
You can install kubectl and kubernetes-dashboard in a k8s cluster (https://kubernetes.io/docs/tasks/tools/install-kubectl/), and then use the kubectl command to query information about a pod or container, or use the kubernetes-dashboard web UI to query information about the cluster.
For more information, please refer to https://kubernetes.io/
kubectl get pods
will show you all your pods and their status. A quick check to make sure that all is at least running.
If there are pods that are unhealthy, then
kubectl describe pod <pod name>
will give some more information.. eg image not found etc
kubectl log <pod name> --all
is often the next step , use -f to follow the logs as you exercise your api.
It is possible to link up images running in a pod with most ide debuggers, but instructions will differ depending on language and ide used...
I'm using Kubernetes 1.11 on Digital Ocean, when I try to use kubectl top node I get this error:
Error from server (NotFound): the server could not find the requested resource (get services http:heapster:)
but as stated in the doc, heapster is deprecated and no longer required from kubernetes 1.10
If you are running a newer version of Kubernetes and still receiving this error, there is probably a problem with your installation.
Please note that to install metrics server on kubernetes, you should first clone it by typing:
git clone https://github.com/kodekloudhub/kubernetes-metrics-server.git
then you should install it, WITHOUT GOING INTO THE CREATED FOLDER AND WITHOUT MENTIONING AN SPECIFIC YAML FILE , only via:
kubectl create -f kubernetes-metrics-server/
In this way all services and components are installed correctly and you can run:
kubectl top nodes
or
kubectl top pods
and get the correct result.
For kubectl top node/pod to work you either need the heapster or the metrics server installed on your cluster.
Like the warning says: heapster is being deprecated so the recommended choice now is the metrics server.
So follow the directions here to install the metrics server
Newbie setup :
Created First project in GCP
Created cluster with default, 3 nodes. Node version 1.7.6. cluster master version 1.7.6-gke.1.
Deployed aan application in a pod, per example.
Able to access "hello world" and the hostname, using the external-ip and the port.
In GCP / GKE webpage of my cloud console, clicked "discovery and loadbalancing", I was able to see the "kubernetes-dashboard" process in green-tick, but cannot access throught the IP listed. tried 8001,9090, /ui and nothing worked.
not using any cloud shell or gcloud commands on my local laptop. Everything is done on console.
Questions :
How can anyone access the kubernetes-dashboard of the cluster created in console?
docs are unclear, are the dashboard components incorporated in the console itself? Are the docs out of sync with GCP-GKE screens?
tutorial says run "kubectl proxy" and then to open
"http://localhost:8001/ui", but it doesnt work, why?
If you create a cluster with with version 1.9.x or greater, then u can access using tokens.
get secret.
kubectl -n kube-system describe secrets `kubectl -n kube-system get secrets | awk '/clusterrole-aggregation-controller/ {print $1}'` | awk '/token:/ {print $2}'
Copy secret.
kubectl proxy.
Open UI using 127.0.0.1:8001/ui. This will redirect to login page.
there will be two options to login, kubeconfig and token.
Select token and paste the secret copied earlier.
hope this helps
It seems to be an issue with the internal Kubernetes DNS service starting at version 1.7.6 on Google Cloud.
The solution is to access the dashboard at this endpoint instead:
http://localhost:8001/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard
Github Issue links:
https://github.com/kubernetes/dashboard/issues/2368
https://github.com/kubernetes/kubernetes/issues/52729
The address of the dashboard service is only accessible from inside of the cluster. If you ssh into a node in your cluster, you should be able to connect to the dashboard. You can verify this by noticing that the address is within the services CIDR range for your cluster.
The dashboard in running as a pod inside of your cluster with an associated service. If you open the Workloads view you will see the kubernetes-dashboard deployment and can see the pod that was created by the deployment. I'm not sure which docs you are referring to, since you didn't provide a link.
When you run kubectl proxy it creates a secure connection from your local machine into your cluster. It works by connecting to your master and then running through a proxy on the master to the pod/service/host that you are connecting to via an ssh tunnel. It's possible that it isn't working because the ssh tunnels are not running; you should verify that your project has newly created ssh rules allowing access from the cluster endpoint IP address. Otherwise, if you could explain more about how it fails, that would be useful for debugging.
First :
gcloud container clusters get-credentials cluster-1 --zone my-zone --project my-project
Then find your kubernetes dashboard endpoint doing :
kubectl cluster-info
It will be something like https://42.42.42.42/api/v1/namespaces/kube-system/services/kubernetes-dashboard/proxy
Install kube-dashboard
kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml
Run:
$ kubectl proxy
Access:
http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/login