MultiCloud Kubernetes Setup

Sangeeth Sahana D
3 min readJan 13, 2022

--

What is MultiCLoud?

Multicloud is a cloud approach made up of more than 1 cloud service, from more than 1 cloud vendor — public or private.

What is Kubernetes?

Kubernetes is an open-source container orchestration platform that enables the operation of an elastic web server framework for cloud applications. Kubernetes can support data center outsourcing to public cloud service providers or can be used for web hosting at scale.

SETUP:

Kubernetes Master Node: AWS

Slave1-Azure

Slave2- GCP

Inventory File:

Kubernetes Master Node AWS

- name: Initializing Kubeadm Servicessetup
command: kubeadm init — pod-network-cidr=10.240.0.0/16 — ignore-preflight-errors=NumCPU — ignore-preflight-errors=Mem
ignore_errors: true- name: Creating .kube directory
file:
path: ~/.kube
state: directory
mode: 0755- name: link the admin.conf with .kube/admin file
file:
src: /etc/kubernetes/admin.conf
dest: ~/.kube/config
state: link
mode: 0644- name: Generating a token
command: kubeadm token create — print-join-command
register: token- name: Set the kubeadm join command globally
set_fact:
kubernetes_join_command: >
{{ token.stdout }}
when: token.stdout is defined
delegate_to: “{{ item }}”
delegate_facts: true
with_items: “{{ groups[‘all’] }}”- name: Transfering network file
copy:
src: kube-flannel.yml
dest: /root/kube-flannel.yml- name: Creating an Overlay Network to connect worker nodes
command: kubectl apply -f /root/kube-flannel.yml

.

$ kubeadm init --pod-network-cidr=10.244.0.0/16 --control-plane-endpoint={{ control_plane_endpoint_ip }}:6443 --ignore-preflight-errors=NumCPU  --ignore-preflight-errors=MeKubernetes Slave-1 over GCP

l

Kubernetes Slave-1 over Azure

# This playbook create an Azure VM with public IP, and open 22 port for SSH, and add ssh public key to the VM.
# This playbook create an Azure VM with public IP
# Change variables below to customize your VM deployment- name: Create Azure VM
hosts: localhost
connection: local
vars:
resource_group: "{{ resource_group_name }}"
vm_name: testvm
location: eastus
ssh_key: "<KEY>"
tasks:
- name: Create a resource group
azure_rm_resourcegroup:
name: "{{ resource_group }}"
location: "{{ location }}" - name: Create virtual network
azure_rm_virtualnetwork:
resource_group: "{{ resource_group }}"
name: "{{ vm_name }}"
address_prefixes: "10.0.0.0/16" - name: Add subnet
azure_rm_subnet:
resource_group: "{{ resource_group }}"
name: "{{ vm_name }}"
address_prefix: "10.0.1.0/24"
virtual_network: "{{ vm_name }}" - name: Create public IP address
azure_rm_publicipaddress:
resource_group: "{{ resource_group }}"
allocation_method: Static
name: "{{ vm_name }}" - name: Create Network Security Group that allows SSH
azure_rm_securitygroup:
resource_group: "{{ resource_group }}"
name: "{{ vm_name }}"
rules:
- name: SSH
protocol: Tcp
destination_port_range: 22
access: Allow
priority: 1001
direction: Inbound - name: Create virtual network interface card
azure_rm_networkinterface:
resource_group: "{{ resource_group }}"
name: "{{ vm_name }}"
virtual_network: "{{ vm_name }}"
subnet: "{{ vm_name }}"
public_ip_name: "{{ vm_name }}"
security_group: "{{ vm_name }}"- name: Create VM
azure_rm_virtualmachine:
resource_group: "{{ resource_group }}"
name: "{{ vm_name }}"
vm_size: Standard_DS1_v2
admin_username: azureuser
ssh_password_enabled: false
ssh_public_keys:
- path: /home/azureuser/.ssh/authorized_keys
key_data: "{{ ssh_key }}"
network_interfaces: "{{ vm_name }}"
image:
offer: CentOS
publisher: OpenLogic
sku: 7.5
version: latest

Kubernetes Slave-2 over GCP

- name: Create an instance
hosts: localhost
gather_facts: no
vars:
gcp_project: my-project
gcp_cred_kind: serviceaccount
gcp_cred_file: /home/my_account.json
zone: "us-central1-a"
region: "us-central1"tasks:
- name: create a disk
gcp_compute_disk:
name: 'disk-instance'
size_gb: 50
source_image: 'projects/ubuntu-os-cloud/global/images/family/ubuntu-1604-lts'
zone: "{{ zone }}"
project: "{{ gcp_project }}"
auth_kind: "{{ gcp_cred_kind }}"
service_account_file: "{{ gcp_cred_file }}"
scopes:
- https://www.googleapis.com/auth/compute
state: present
register: disk
- name: create a address
gcp_compute_address:
name: 'address-instance'
region: "{{ region }}"
project: "{{ gcp_project }}"
auth_kind: "{{ gcp_cred_kind }}"
service_account_file: "{{ gcp_cred_file }}"
scopes:
- https://www.googleapis.com/auth/compute
state: present
register: address
- name: create a instance
gcp_compute_instance:
state: present
name: test-vm
machine_type: n1-standard-1
disks:
- auto_delete: true
boot: true
source: "{{ disk }}"
network_interfaces:
- network: null # use default
access_configs:
- name: 'External NAT'
nat_ip: "{{ address }}"
type: 'ONE_TO_ONE_NAT'
zone: "{{ zone }}"
project: "{{ gcp_project }}"
auth_kind: "{{ gcp_cred_kind }}"
service_account_file: "{{ gcp_cred_file }}"
scopes:
- https://www.googleapis.com/auth/compute
register: instance- name: Wait for SSH to come up
wait_for: host={{ address.address }} port=22 delay=10 timeout=60- name: Add host to groupname
add_host: hostname={{ address.address }} groupname=new_instances

Setting up as Worker Nodes

- name: connecting to the master node  shell: >  {{ kubernetes_join_command }}

That’s it we are done it setting up the cluster.

Requirements of the task are met!

--

--