I installed Microk8s on a local physical Ubuntu 20-04 server (without a GUI):
microk8s status --wait-ready
microk8s is running
high-availability: no
datastore master nodes: 127.0.0.1:19001
datastore standby nodes: none
addons:
enabled:
ha-cluster # Configure high availability on the current node
helm # Helm 2 - the package manager for Kubernetes
disabled:
When I try to install something with helm it says:
Error: INSTALLATION FAILED: Kubernetes cluster unreachable: Get "http://localhost:8080/version": dial tcp 127.0.0.1:8080: connect: connection refused
What configuration has to be done to use the MicroK8s Kubernetes cluster for helm installations?
Do I have to enable more MicroK8s services for that?
Can I run a Kubernetes cluster on one or two single local physical Ubuntu server with MicroK8s?
Searching for solution for your issue, I have found this one. Try to run:
[microk8s] kubectl config view --raw > ~/.kube/config
Helm interacts directly with the Kubernetes API server so it needs to be able to connect to a Kubernetes cluster. Helms reads the same configuration files used by kubectl to do it automatically.
Based on Learning Helm by O'Reilly Media:
Helm will try to find this information by reading the environment variable $KUBECONFIG. If that is not set, it will look in the same default locations that kubectl looks in.
See also:
This discussion about similar issue on Github
This similar issue
Related
I've installed RabbitMQ on a Kubernetes Cluster using Helm as follows:
helm repo add bitnami https://charts.bitnami.com/bitnami
helm install my-release bitnami/rabbitmq-cluster-operator
Then I setup a Go Client something like this running as a service on the same Kubernetes Cluster
import amqp "github.com/rabbitmq/amqp091-go"
conn, err = amqp.Dial("amqp://guest:guest#localhost:5672/")
But the client fails to connect. How do I figure out what the host and port should be set to for RabbitMQ on a Kubernetes Cluster?
If your Go client is running as a microservice on the same cluster, you need to use the appropriate DNS record to access it, localhost just attempts to access the Go client microservice itself.
In the namespace where RabbitMQ is installed, you can run kubectl get svc and there should be a ClusterIP service running with port 5672, likely called my-release.
You can then connect to it from any other service in the cluster with my-release.NAMESPACE.svc.DOMAIN.
The Helm release notes also show how to connect to the service, as well as many other helpful notes like authentication username and password, as well as external access availability etc.
helm get notes my-release
Kubernetes version: 1.21.0
Cloud being used: bare-metal
Installation method: kubeadm
Host OS: centos 7
CNI version: Flannel v0.3.1
CRI and version: Docker v20.10.7
How to backup etcd in my current setup?
The etcdcl command gives an error:
-bash: etcdctl: command not found
The etcdctl command doesn’t work in my current setup please help.
Thanks
You need to install etcdctl on your local machine.
Please follow etcd installation documentation.
For instance you can find v.3.5.0 here with instuctions.
As for backing up the etcd you can refer to kubernetes documentation - Backing up an etcd cluster
Also you may consider using some dedicated solutions to fully backup kubernetes cluster. One of the examples is Velero
I am trying to setup my very first Kubernetes cluster and it seems to have setup fine until nginx-ingress controller.
Here is my cluster information:
Nodes: three RHEL7 and one RHEL8 nodes
Master is running on RHEL7
Kubernetes server version: 1.19.1
Networking used: flannel
coredns is running fine.
selinux and firewall are disabled on all nodes
Here are my all pods running in kube-system
I then followed instructions on following page to install nginx ingress controller: https://docs.nginx.com/nginx-ingress-controller/installation/installation-with-manifests/
Instead of deployment, I decided to use daemon-set since I am going to have only few nodes running in my kubernetes cluster.
After following the instructions, pod on my RHEL8 is constantly failing with the following error:
Readiness probe failed: Get "http://10.244.3.2:8081/nginx-ready": dial
tcp 10.244.3.2:8081: connect: connection refused Back-off restarting
failed container
Here is the screenshot shows that RHEL7 pods are working just fine and RHEL8 is failing:
All nodes are setup exactly the same way and there is no difference.
I am very new to Kubernetes and don't know much internals of it. Can someone please point me on how can I debug and fix this issue? I am really willing to learn from issues like this.
This is how I provisioned RHEL7 and RHEL8 nodes
Installed docker version: 19.03.12, build 48a66213fe
Disabled firewalld
Disabled swap
Disabled SELinux
To enable iptables to see bridged traffic, set net.bridge.bridge-nf-call-ip6tables = 1 and net.bridge.bridge-nf-call-iptables = 1
Added hosts entry for all the nodes involved in Kubernetes cluster so that they can find each other without hitting DNS
Added IP address of all nodes in Kubernetes cluster on /etc/environment for no_proxy so that it doesn't hit corporate proxy
Verified docker driver to be "systemd" and NOT "cgroupfs"
Reboot server
Install kubectl, kubeadm, kubelet as per kubernetes guide here at: https://kubernetes.io/docs/tasks/tools/install-kubectl/
Start and enable kubelet service
Initialize master by executing the following:
kubeadm init --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12
Apply node-selector patch for mixed OS scheduling
wget https://raw.githubusercontent.com/Microsoft/SDN/master/Kubernetes/flannel/l2bridge/manifests/node-selector-patch.yml
kubectl patch ds/kube-proxy --patch "$(cat node-selector-patch.yml)" -n=kube-system
Apply flannel CNI
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
Modify net-conf.json section of kube-flannel.yml for a type "host-gw"
kubectl apply -f kube-flannel.yml
Apply node selector patch
kubectl patch ds/kube-flannel-ds-amd64 --patch "$(cat node-selector-patch.yml)" -n=kube-system
Thanks
According to kubernetes documentation the list of supported host operating systems is as follows:
Ubuntu 16.04+
Debian 9+
CentOS 7
Red Hat Enterprise Linux (RHEL) 7
Fedora 25+
HypriotOS v1.0.1+
Flatcar Container Linux (tested with 2512.3.0)
This article mentioned that there are network issues on RHEL 8:
(2020/02/11 Update: After installation, I keep facing pod network issue which is like deployed pod is unable to reach external network
or pods deployed in different workers are unable to ping each other
even I can see all nodes (master, worker1 and worker2) are ready via
kubectl get nodes. After checking through the Kubernetes.io official website, I observed the nfstables backend is not compatible with the
current kubeadm packages. Please refer the following link in “Ensure
iptables tooling does not use the nfstables backend”.
The simplest solution here is to reinstall the node on supported operating system.
Environment of kubectl: Windows 10.
Kubectl version: https://storage.googleapis.com/kubernetes-release/release/v1.15.0/bin/windows/amd64/kubectl.exe
Hello. I've just installed Kubernetes cluster at Google Cloud Platform. Then applied the next command:
gcloud container clusters get-credentials my-cluster --zone europe-west1-b --project my-project
It successfully added the credentials at %UserProfile%\.kube\config
But when I try kubectl get pods it returns Unable to connect to the server: EOF. My computer accesses the internet through corporate proxy. How and where could I provide cert file for the kubectl so it could use the cert with all the requests? Thanx.
You would get EOF if there is no response from kubectl API calls in a certain time(Idle time is set 300 sec by default).
Try increasing cluster Idle time or maybe you might need VPN to access those pods (something like those)
I have followed the installation steps:
https://cloud.google.com/container-engine/docs/tutorials/guestbook#install_gcloud_and_kubectl
A Google Container Engine cluster is up and running and gcloud CLI is authenticated and works.
But kubectl says:
"couldn't read version from server: Get http://local host:8080/api: dial tcp 127.0.0.1:8080: connection refused"
I think I need to use kubectl config set-cluster to setup the connection to my cluster on GCE.
Where do I find the address of the Kubernetes master of my GCE cluster?
With gcloud beta container clusters list I seemingly get the master IP of my cluster.
I used that with kubectl config set-cluster.
Now it says:
"error: couldn't read version from server: Get http:// 104.197.49.119/api: dial tcp 104.197.49.119:80: i/o timeout"
Am I on the right track with this?
Additional strangeness:
gcloud container or gcloud preview container doesn't work for me. Only gcloud beta container
MASTER_VERSION of my cluster is 0.21.4, while the version of my kubectl client is GitVersion:"v0.20.2", even though freshly installed with gcloud.
Run
gcloud container clusters get-credentials my-cluster-name
to update the kubeconfig file and point kubectl at a cluster on Google Container Engine.
as #ScyDev stated
Run:
gcloud container get-credentials <cluster_name>
But you may have to set your compute zone before, in case you initialized a new cloud shell terminal. That was my case
if you're working in windows (ex. powershell), you need to check this out:
https://github.com/kubernetes/kubernetes/issues/34395