Steps to manually setup a cluster on Google Cloud Platform using rancher

1. Get new SSH keys!

You will need SSH keys to connect to VM on GCP. This key will be passed to createvm script which will include your public key during the machine creation.

ssh-keygen -t rsa -f <key-path> -C <your-username>

E.g:

ssh-keygen -t rsa -f ~/.ssh/vmkey -C devops

# 2. Configure the startup script

You can configure a script to perform tasks during the startup, such as updates or programs installation.

Inside the folder scripts you can reach the startup_script.sh. Wich is configured to install git and docker on VM.

scripts/startup.sh:

#! /bin/bash
sudo su
apt-get install git -y
curl https://releases.rancher.com/install-docker/20.10.sh | sh
usermod -aG docker ubuntu

3. Create VM instances

The createvm is a wrapper for the gcloud command. This will automatically update a default VM model with new IP and name and will pass the startup script and the SSH key.

Inside the script, you must replace PROJECT and ZONE variables with yours.

$ cd scripts
$ ./createvm.sh --ip=34.95.134.36 --name=k8s0 --key=/home/maike/.ssh/vmkey.pub --script=./startup.sh --username=devops
$ ./createvm.sh --ip=35.198.57.145 --name=k8s1 --key=/home/maike/.ssh/vmkey.pub --script=./startup.sh --username=devops
$ ./createvm.sh --ip=35.247.212.89 --name=k8s2 --key=/home/maike/.ssh/vmkey.pub --script=./startup.sh --username=devops
$ ./createvm.sh --ip=34.151.241.74 --name=rancher-server --key=/home/maike/.ssh/vmkey.pub --script=./startup.sh --username=devops

3.1 Transfer ssh key

$ ssh -i ~/.ssh/vmkey devops@34.95.134.36
$ exit
$ ssh -i ~/.ssh/vmkey devops@35.198.57.145
$ exit
$ ssh -i ~/.ssh/vmkey devops@35.247.212.89
$ exit
$ ssh -i ~/.ssh/vmkey devops@34.151.241.74
$ exit

4. Install rancher

Login on rancher VM:

$ ssh devops@34.151.241.74 'sudo mkdir /opt/rancher'

Install the rancher container

$ ssh devops@34.151.241.74 'sudo docker run -d -v /opt/rancher:/var/lib/rancher --restart=unless-stopped -p 80:80 -p 443:443 --privileged rancher/rancher:v2.4.3'

Access the GCP console, under VM instances edit the rancher-server VM and mark the option "Accept HTTP"

Wait until the rancher is up to work and access the rancher-server IP(34.151.241.74) in your browser.

If the rancher version is v2.6.2+:

Follow the instructions and login on rancher.

docker logs `docker ps --format {{.ID}}` 2>&1 | grep "Bootstrap Password:"

5. Install kubectl on rancher

Run the script install_kubectl on the rancher-server

$ cd scripts
$ ssh devops@34.151.241.74 'bash -s' < install_kubectl.sh

Under rancher go to Cluster -> Click on "Kubeconfig File" -> Copy the content to clipboard

Paste the content on the file "~/.kube/config" under the rancher-server machine

$ sudo nano ~/.kube/config

Test if is working

$ kubectl get nodes

6. Create cluster

Login on rancher go to Cluster Managment -> Create (button)-> Custom -> Next -> Mark etcd and Control Plane (checkbox)

Copy the generated code and paste in a file called node_command.sh and execute for each node IP:

$ cd scripts
$ ssh devops@34.95.134.36 'bash -s' < node_command.sh   #-k8s0
$ ssh devops@35.198.57.145 'bash -s' < node_command.sh   #-k8s1
s ssh devops@35.247.212.89 'bash -s' < node_command.sh   #-k8s2

Wait until the cluster is up to work. You can see the cluster status on rancher web page -> Cluster Management

7. Install applications

• traefik : ingress controller
• longhorn & persistent volumes
• graylog : monitoring
• cronjob : run job periodically
• configmap : store non-confidential data in key-value pairs
• secrets : store sensitive data such as password, token or key
• liveness : periodically check application status

8. Extras

• limit