Rancher

Prerequisites

Before starting, ensure you have:

1. 4+ Virtual Machines (VMs) running Ubuntu

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Rancher Setup Walkthrough

1. Prepare Rancher Host

Login to your designated Rancher management VM. This should be a separate node from your K3s cluster.

2. Docker Installation (Optional)

For systems requiring container runtime:

# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add repository to Apt sources:
echo \
"deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
$(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}") stable" | \
sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update

# Install Docker components:
sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Verify installation:

docker -v && docker compose version

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Rancher Deployment

1. Docker Compose Configuration

Create docker-compose.yml with:

services:
  rancher:
    image: rancher/rancher:v2.10.2
    restart: unless-stopped
    container_name: rancher
    ports:
      - "80:80/tcp"
      - "443:443/tcp"
    volumes:
      - "./rancher-data:/var/lib/rancher"
    privileged: true

2. Launch Rancher

Start the container stack:

sudo docker compose up -d

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Rancher Initial Configuration

1. Access Web UI

Navigate to https://<your-vm-ip> in your browser

2. Retrieve Bootstrap Password

Get initial credentials:

sudo docker logs rancher 2>&1 | grep "Bootstrap Password:"

3. Cluster Creation

1. From dashboard, click Create Cluster
2. Select Custom cluster type
3. Configure options:
   • Kubernetes Version: k3s latest
   • Disable unnecessary services (e.g., Traefik)
4. Click Create

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Node Management

1. Add Cluster Nodes

1. Navigate to cluster’s Registration tab
2. Select Insecure registration method
3. Copy registration command
4. Execute command on each worker node

2. Monitor Node Joining

Check node status in Machines tab. Allow 5-10 minutes for full provisioning.

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Import Existing K3s Cluster

1. Cluster Import

1. From Home, click Import Existing
2. Select Generic provider
3. Name your cluster and click Create

2. Registration Command

Copy and execute the provided command on your existing K3s master node:

kubectl apply -f https://<rancher-server>/v3/import/<cluster-id>.yaml

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Verification & Testing

Confirm successful setup:

1. Check all nodes show “Active” status
2. Verify cluster health in Rancher dashboard
3. Test workload deployment through Rancher UI

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🎉 Congratulations! You’ve successfully deployed Rancher management platform and integrated K3s clusters!

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Maintenance Tips

• Regularly back up rancher-data volume
• Monitor certificate expiration dates
• Keep Rancher updated to latest stable version

Useful References

• Rancher Official Documentation
• Docker Installation Guide
• K3s Cluster Management