https://github.com/git719/kube
Simple K8s cluster
https://github.com/git719/kube
kubernetes
Last synced: 12 months ago
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Simple K8s cluster
- Host: GitHub
- URL: https://github.com/git719/kube
- Owner: git719
- License: mit
- Created: 2022-05-04T20:44:57.000Z (almost 4 years ago)
- Default Branch: main
- Last Pushed: 2022-05-04T21:15:21.000Z (almost 4 years ago)
- Last Synced: 2025-01-14T10:29:38.033Z (about 1 year ago)
- Topics: kubernetes
- Language: Shell
- Homepage:
- Size: 7.81 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Simple Kubernetes Cluster
A minimalist [Kubernetes](https://kubernetes.io/) cluster with [kubeadm](https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/) using the [vm](https://github.com/lencap/vm), which is a small utility that behaves a bit like Vagrant.
## Quick Start Guide
1. The first step is to install the latest version of [vm](https://github.com/lencap/vm):
* `brew install lencap/tools/vm`
* Afterwards, run `vm` to get familiar with its usage, and to ensure that the SSH keys are created under `~/.vm`.
2. The next step is to create the `centos7.7.1908.ova` or `ubuntu1804.ova` OS image by running `vm imgpack` and following those instructions.
3. Beforehand, adjust the number of CPUs and Memory settings in `kube-.conf` to better suit your need. Then run `vm prov kube-.conf` to provision the 2 VMs.
4. Open a separate SSH shell session to each:
* `vm ssh k2`
* `vm ssh k3`
5. Initialize the cluster from master k2 host:
* `sudo kubeadm init --service-cidr 10.96.0.0/12 --pod-network-cidr=192.168.0.0/16 --apiserver-advertise-address 10.11.12.2`
* The `--pod-network-cidr`setting is needed for Calico neetworking.
6. If Kubernetes master has initialized successfully, setup `kubectl` wherever you need to from the files in the k2 host:
* `mkdir -p $HOME/.kube`
* `sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config`
* `sudo chown $(id -u):$(id -g) $HOME/.kube/config`
7. Install Calico as the Pod network add-on (get latest non-beta version):
* `curl -O https://docs.projectcalico.org/v3.12/manifests/calico.yaml`
* `vi calico.yaml` and make any necessary adjustments
* `kubectl apply -f calico.yaml`
* Afterwards check that the CoreDNS Pod is Running in the output of `kubectl get pods --all-namespaces`. And once the CoreDNS Pod is up and running, you can continue by joining your nodes.
8. Join k3 host as a member node:
* On k2 host run: `sudo kubeadm token create --print-join-command`
* On k3 host use output of above command to join cluster (as root, sudo)
## Other Steps
* If you're having issues and want to tear everything down and start over. The easiest thing to do is to delete the two VMs with `vm del k2 -f`, and on, then reprovision. Alternatively you can try:
* `sudo kubeadm reset -f && iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X && ipvsadm -C`
* Confirm both nodes are running:
* `kubectl get nodes`
```
NAME STATUS ROLES AGE VERSION
k2 Ready master 19m v1.17.0
k3 Ready 11m v1.17.0
```
* Restart Kuberlet engine
* `systemctl daemon-reload && systemctl restart kubelet && systemctl status kubelet`
* Verify Cluster info
* `kubectl cluster-info`
## Notes
Install the https://github.com/ahmetb/kubectx utility wherever you're running `kubectl` from, to more easily switch context and namespaces.