kubernetes

Installation of kubernetes cluster in private cloud using kubeadm.

Configuration

The following table lists the configurable parameters of the kubernetes cluster install and their default values.

Installation steps:

• Install Cluster

cd /root/kubernetes/install_cluster
./install_master_node.sh

• Install kubernetes:

  • Master:

  cd /root/kubernetes/install_k8s
  ./install-k8s.sh
  

  • Worker:

  cd /root/kubernetes/install_k8s
  ./install-k8s-worker.sh
  

  • To join a worker node:

  sodo kubeadm join master_ip:master_port --token token_id --discovery-token-ca-cert-hash hash_cert
  

  • To remoave a kubernetes setup:

  kubeadm reset
  

  • To create a new join token

  kubeadm token create print-join-command
  

When installation of master is completed you should see below components in kube-system namespace

When you reboot the vms, the kubelet service may not run, you need to restart the kubelet.

sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
sudo swapoff -a

systemctl stop kubelet
syatemctl start kubelet

Or Execute below command

./start_cluster.sh

Other debugging steps

systemctl status kubelet
journalctl -u kubelet

Useful commands:

• To change namespace

alias kcd='kubectl config set-context $(kubectl config current-context) --namespace'
kcd name_space

• Inorder to login via OpenId Connect username/password

alias kctl='kubectl --kubeconfig=/root/oauth.conf --token=$(python3 /root/kubernetes/install_k8s/kube-login/cli-auth.py)'

In order to use the above approach, you must install and run

1. Ingress Instress ReadME
2. Kubeauthentication service KubeAuth ReadME

• To enable verbose(logging) of kubectl command

kubectl get pods --v 6

Useful commands

kubectl top nodes --v 6

kubectl get pod, svc, hpa -owide
watch -n1 !!

kubectl get componentstatus

Automation of build and deployment

Note: Ingress should be installed before this can begin.

• Execute below command to install ci/cd pipeline

cd /root/kubernetes/install_k8s/
./setuUp-devops.sh 

This would install local docker registry, Git webhook, Docker webhook and Helm webhook

Architecture of the pipeline

In order to test the pipeline use hlw repository, make a sample change and commit.

Application would be accessible in https://master.cloud.com:32028/hlw

Installing components

1. Ingress Controller: Link
2. Kube Login Webhook
3. Devops: Githook, Dockerhook,Reghook
4. Kubernetes Dashboard: Link
5. Kube Authentication
6. Ldap: Link
7. Kerberos: Link
8. Ldap Client: Link
9. Ldap Client2: Link

• Add ca.crt and server.crt file in chrome browser, please refer link on how to add certificate. Add server.crt in Other People tab and ca.crt in Trusted Root Certificate Authority tab.
• Add ip_address master.cloud.com to windows host file located in C:\Windows\System32\drivers\etc. e.g. 192.168.1.5 master.cloud.com >> host file.

Setup Https for Kubernetes Cluster

Work in progress

Refer to HTTPS Setup with Kubernetes