Setting up MetalLB Load Balancer with Kubernetes k8s.

When we are deploying the Kubernetes in the local development environment and if we need to publish the services through load balancer services then Metallb load balancer is one of the easiest solutions we can use. All we need is a set of IP range from our network which metal lb can use.  

Following are the k8s configurations that need to be applied on the cluster. 

Below is the config map which mentions the IPs which can be used for the load balancers. 

apiVersion: v1

kind: ConfigMap

metadata:

namespace: metallb-system

name: config

data:

config: |

address-pools:

- name: default

protocol: layer2

addresses:

- 172.16.2.80-172.16.2.90

Below is the ansible-playbook I used to deploy the metal load balancer on the k8s cluster. 

• Initialize the master with Metallb Clusters
• Copy the metallb Configuration to master
• Kube apply the configuration on master. 

- hosts: master

remote_user: ansible

become: yes

become_method: sudo

become_user: root

gather_facts: yes

connection: ssh

tasks:

- name: Initializing Metallb cluster

shell: kubectl apply -f https://raw.githubusercontent.com/google/metallb/v0.8.3/manifests/metallb.yaml

register: myshell_output

- name: Copying the Metallb config file

copy:

src: /Users/rahulraj/workspace/vmware-ansible/k8s/playbook/metallb-congif.yml

dest: $HOME/metallb-congif.yml

- name: Configuring Metallb cluster

shell: kubectl apply -f $HOME/metallb-congif.yml

register: myshell_output

For testing it we shall deploy a sample Nginx and expose it through load balancer type services. 

k create deployment nginx-deployments --image=nginx --replicas=3 --port=80

k expose deployment nginx-deployments --port=80 --target-port=80 --type=LoadBalancer

Output should be like following 

 kubectl get svc

NAME                TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE

kubernetes          ClusterIP      10.96.0.1        <none>        443/TCP        25h

nginx-deployments   LoadBalancer   10.100.137.154   172.16.2.80   80:30973/TCP   13h

Kubernetes(k8s) With Ansible Over Ubuntu Machines with Docker

Kubernetes(k8s) is a popular container orchestration system that provides a powerful platform for managing containerized applications. Docker is a lightweight, yet powerful container runtime that provides the underlying infrastructure for many Kubernetes deployments. In this, we can see how to set up Kubernetes with Docker using Ansible over Ubuntu machines.

Environment

• Ubuntu VM's running on Vmware
• K8s with Docker Runtime

** Important Notice: Following Settings are not working since the new release of 1.27. Please make use of the deployment with Containers.

https://www.adminz.in/2022/01/kubernetes-with-containerd-using-ansible.html

User Creation

• Asks for the User Name which has to be created
• Create's the user
• Adds a dedicated Sudo entry 
• Setting up Password less sudo for user
• Copy the local uses ssh key to server for password less auth
• Print the details
• Updates the System

- hosts: all

become: yes

vars_prompt:

- name: "new_user"

prompt: "Account need to be create in remote server."

private: no

tasks:

- name: creating the user {{ new_user }}.

user:

name: "{{ new_user }}"

createhome: yes

shell: /bin/bash

append: yes

state: present

- name: Create a dedicated sudo entry file for the user.

file:

path: "/etc/sudoers.d/{{ new_user }}"

state: touch

mode: '0600'

- name: "Setting up Sudo without Password for user {{ new_user }}."

lineinfile:

dest: "/etc/sudoers.d/{{ new_user }}"

line: '{{ new_user }} ALL=(ALL) NOPASSWD: ALL'

validate: 'visudo -cf %s'

- name: Set authorized key for user copying it from current {{ new_user }} user.

authorized_key:

user: "{{ new_user }}"

state: present

key: "{{ lookup('file', lookup('env','HOME') + '/.ssh/id_rsa.pub') }}"

- name: Print the created user.

shell: id "{{ new_user }}"

register: new_user_created

- debug:

msg: "{{ new_user_created.stdout_lines[0] }}"

- name: "Update cache & Full system update"

apt:

update_cache: true

upgrade: dist

cache_valid_time: 3600

force_apt_get: true

Package Installation in Master and Worker Nodes

• Copy the local host files to all the server for name resolution
• update the hostnames of the machines based on the names in host file
• Temporary Swap off
• Swap off in fstab
• Installing Kubernetes Pre-requisites packages
• Adding Docker Packages Keys
• Adding Docker Respository
• Install Docker packages
• Enables Docker Services
• Add Google repositories keys
• Create Directory for Docker deamon file
• Create the docker deamon file with Overlay details
• Restart Docker Services
• Install Kubernetes Packages
• Enabled K8s Services
• Reboot the Servers

- hosts: "master, workers"

remote_user: ansible

become: yes

become_method: sudo

become_user: root

gather_facts: yes

connection: ssh

tasks:

- name: Copying the host file

copy:

src: /etc/hosts

dest: /etc/hosts

owner: root

group: root

- name: "Updating hostnames"

hostname:

name: "{{ new_hostname }}"

- name: Make the Swap inactive

command: swapoff -a

- name: Remove Swap entry from /etc/fstab.

lineinfile:

dest: /etc/fstab

regexp: swap

state: absent

- name: Installing Prerequisites for Kubernetes

apt:

name:

- apt-transport-https

- ca-certificates

- curl

- gnupg-agent

- vim

- software-properties-common

state: present

- name: Add Docker’s official GPG key

apt_key:

url: https://download.docker.com/linux/ubuntu/gpg

state: present

- name: Add Docker Repository

apt_repository:

repo: deb [arch=amd64] https://download.docker.com/linux/ubuntu xenial stable

state: present

filename: docker

mode: 0600

- name: Install Docker Engine.

apt:

name:

- docker-ce

- docker-ce-cli

- containerd.io

state: present

- name: Enable service docker, and enable persistently

service:

name: docker

enabled: yes

- name: Add Google official GPG key

apt_key:

url: https://packages.cloud.google.com/apt/doc/apt-key.gpg

state: present

- name: Creates directory

file:

path: /etc/docker/

state: directory

- name: Creating a file with content

copy:

dest: "/etc/docker/daemon.json"

content: |

{

"exec-opts": ["native.cgroupdriver=systemd"],

"log-driver": "json-file",

"log-opts": {

"max-size": "100m"

},

"storage-driver": "overlay2"

}

- name: restart docker

service:

name: docker

state: restarted

enabled: yes

- name: Add Kubernetes Repository

apt_repository:

repo: deb http://apt.kubernetes.io/ kubernetes-xenial main

state: present

filename: kubernetes

mode: 0600

- name: Installing Kubernetes Cluster Packages.

apt:

name:

- kubeadm

- kubectl

- kubelet

state: present

- name: Enable service kubelet, and enable persistently

service:

name: kubelet

enabled: yes

- name: Reboot all the kubernetes nodes.

reboot:

msg: "Reboot initiated by Ansible"

connect_timeout: 5

reboot_timeout: 3600

pre_reboot_delay: 0

post_reboot_delay: 30

test_command: whoami

Master Configuration

• Pulls all needed images
• Reset Kubeadm if its already configured
• Initialize K8s cluster
• Create Directory for Kube config file in master
• Create a local kube config file in master
• Copy the kube config file to ansible local server
• Genarates the Kube toke for workers and stores it
• Copy the token to master's tmp directory
• Copy the toke to ansible local tmp direcotry
• Initialize the pod network with fannel
• Copy the output to mater file
• Copy the output to ansible local server

- hosts: master

remote_user: ansible

become: yes

become_method: sudo

become_user: root

gather_facts: yes

connection: ssh

tasks:

- name: Pulling images required for setting up a Kubernetes cluster

shell: kubeadm config images pull

- name: Resetting kubeadm

shell: kubeadm reset -f

register: output

- name: Initializing Kubernetes cluster

shell: kubeadm init --apiserver-advertise-address=$(ip a |grep ens160| grep 'inet ' | awk '{print $2}' | cut -f1 -d'/') --pod-network-cidr 10.244.0.0/16 --v=5

register: myshell_output

- debug: msg="{{ myshell_output.stdout }}"

- name: Create .kube to home directory of master server

file:

path: $HOME/.kube

state: directory

mode: 0755

- name: Copy admin.conf to user's kube config to master server

copy:

src: /etc/kubernetes/admin.conf

dest: $HOME/.kube/config

remote_src: yes

- name: Copy admin.conf to user's kube config to ansible local server

become: yes

become_method: sudo

become_user: root

fetch:

src: /etc/kubernetes/admin.conf

dest: /Users/rahulraj/.kube/config

flat: yes

- name: Get the token for joining the nodes with Kuberentes master.

shell: kubeadm token create --print-join-command

register: kubernetes_join_command

- debug:

msg: "{{ kubernetes_join_command.stdout_lines }}"

- name: Copy K8s Join command to file in master

copy:

content: "{{ kubernetes_join_command.stdout_lines[0] }}"

dest: "/tmp/kubernetes_join_command"

- name: Copy join command from master to local ansible server

fetch:

src: "/tmp/kubernetes_join_command"

dest: "/tmp/kubernetes_join_command"

flat: yes

- name: Install Pod network

shell: kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

register: myshell_output

- name: Copy the output to master file

copy:

content: "{{ myshell_output.stdout }}"

dest: "/tmp/pod_network_setup.txt"

- name: Copy network output from master to local ansible server

fetch:

src: "/tmp/pod_network_setup.txt"

dest: "/tmp/pod_network_setup.txt"

flat: yes

Worker Configuration

• Copy the token from ansible local file to worker nodes
• Reset the kubeadm 
• Join the Worker node to Master by running the command

- hosts: workers

remote_user: ansible

become: yes

become_method: sudo

become_user: root

gather_facts: yes

connection: ssh

tasks:

- name: Copy token to worker nodes.

become: yes

become_method: sudo

become_user: root

copy:

src: /tmp/kubernetes_join_command

dest: /tmp/kubernetes_join_command

mode: 0777

- name: Resetting kubeadm

shell: kubeadm reset -f

register: output

- name: Join the Worker nodes with the master.

become: yes

become_method: sudo

become_user: root

command: sh /tmp/kubernetes_join_command

register: joined_or_not

- debug:

msg: "{{ joined_or_not.stdout }}"

K8s should be up with the worker nodes now. 

Manage Vmware Machines With Ansible

Here we are looking on how to use Ansible to connect to vCenters and manage VMs. The focus will be on using quick playbooks for cloning and deleting a current template VM.

We can see the playbook for the creation process for cloning and deleting VMs. The playbook creation process will involve setting up variables, tasks, and handlers, and will be broken down into simple, easy-to-follow steps. Sample playbooks will be provided as a starting point for managing VMs in vCenter using Ansible.

Clone a VM in Vcenter with Ansible Playbook

- hosts: localhost

gather_facts: no

vars:

vcenter_server: "xxx.xxx.xxx.xxx"

vcenter_user: "User-Name"

vcenter_pass: "Password"

datacenter_name: "DC-Name"

cluster_name: "xxx.xxx.xxx.xxx"

resources_pool: "RG-Name"

template_vm: "Template-Name"

serv:

- vm1

- vm2

tasks:

- name: Clone the template

vmware_guest:

hostname: "{{ vcenter_server }}"

username: "{{ vcenter_user }}"

password: "{{ vcenter_pass }}"

resource_pool: "rahul-test"

validate_certs: False

name: "{{ item }}"

template: "{{ template_vm }}"

datacenter: "{{ datacenter_name }}"

folder: /{{ datacenter_name }}/vm

state: poweredon

wait_for_ip_address: yes

register: "r"

with_items: "{{ serv }}"

- debug :

msg: "This is the Host-IPs: {{ item.instance.ipv4 }} {{ item.instance.hw_name }}"

with_items: "{{ r.results}}"

loop_control:

label: "{{ item.instance.hw_name }}"

Shutdown a VM in Vcenter with Ansible Playbook

- hosts: localhost

gather_facts: no

vars:

vcenter_server: "xxx.xxx.xxx.xxx"

vcenter_user: "User-Name"

vcenter_pass: "Password"

datacenter_name: "DC-Name"

cluster_name: "xxx.xxx.xxx.xxx"

tasks:

- name: Shutdown the template

vmware_guest:

hostname: "{{ vcenter_server }}"

username: "{{ vcenter_user }}"

password: "{{ vcenter_pass }}"

validate_certs: False

name: "{{ item}}"

datacenter: "{{ datacenter_name }}"

folder: /{{ datacenter_name }}/vm

state: poweredoff

wait_for_ip_address: yes

loop:

- vm1

- vm2

Delete a VM in Vcenter with Ansible Playbook

- hosts: localhost

gather_facts: no

vars:

vcenter_server: "xxx.xxx.xxx.xxx"

vcenter_user: "User-Name"

vcenter_pass: "Password"

datacenter_name: "DC-Name"

cluster_name: "xxx.xxx.xxx.xxx"

tasks:

- name: Delete the template

vmware_guest:

hostname: "{{ vcenter_server }}"

username: "{{ vcenter_user }}"

password: "{{ vcenter_pass }}"

validate_certs: False

name: "{{ item}}"

datacenter: "{{ datacenter_name }}"

folder: /{{ datacenter_name }}/vm

state: absent

wait_for_ip_address: yes

loop:

- vm1

- vm2

Ansible for Vcenter Module not found error

When working with vCenter and Ansible, you may encounter an error that says "vmware_guest Module not found." This error occurs when the vmware_guest module is not installed on your system.

To resolve this error, you need to install the community.vmware collection, which contains the vmware_guest module. You can do this by running the following command:

To install it use: ansible-galaxy collection install community.vmware.

This command will download and install the community.vmware collection, which contains the vmware_guest module. Once installed, you should be able to use the module in your Ansible playbooks without encountering any errors.

Test WinRm connection to Windows Env

To check if WinRM (Windows Remote Management) is enabled in a Windows Server, you can use the following commands:

Test-NetConnection -ComputerName XX -Port 5986

This command tests the connection to port 5986, which is the default port used by WinRM over HTTPS.

Test-NetConnection -ComputerName XX -Port 5985

This command tests the connection to port 5985, which is the default port used by WinRM over HTTP.

If the above commands return successful results, it means that WinRM is enabled and running on the specified server.

Additionally, you can also use the following command to check if WinRM is configured properly on a remote server:

Test-WSMan -ComputerName XX

This command tests the Windows Remote Management (WinRM) service on a remote server and returns the current configuration status of WinRM.

Sed Command in MAC

The sed command is used to manipulate and edit text in Unix-based operating systems like macOS.

Method to use Sed in Mac

sudo sed -i "/kube/d" /etc/hosts

give error sed: 1: "/etc/hosts": extra characters at the end of h command

In the first command you provided, sudo sed -i "/kube/d" /etc/hosts, the -i option tells sed to edit the file in place, and /kube/d is the command that tells sed to delete any lines containing the string "kube" in the /etc/hosts file. However, this command does not work on macOS as it requires the -i option to have a backup file extension specified. The error message "sed: 1: "/etc/hosts": extra characters at the end of h command" is indicating that the command is not properly formatted for macOS.

To fix this, you can use the following command: sudo sed -i '' '/kube/d' /etc/hosts. The empty quotes after -i specify that no backup file should be created, and the '' is necessary for macOS to recognize the command properly. The /kube/d command remains the same and tells sed to delete any lines containing the string "kube" in the /etc/hosts file.

Following Syntax Worked. 

sudo sed -i '' '/kube/d' /etc/hosts

Converting Text Case in Linux: Exploring Powerful Command-Line Tools

In the realm of command-line utilities, Linux offers a plethora of versatile tools that empower users to perform a wide range of tasks efficiently. One such task involves converting the case of text within a file. Whether you're looking to transform text to lowercase or uppercase, Linux provides multiple command-line options to achieve this. In this article, we'll delve into the process of converting text case using four prominent tools: dd, awk, perl, and sed.

Converting Text to Lowercase

Using dd

The dd command, renowned for its data manipulation capabilities, can also be employed to convert text to lowercase.

$ dd if=input.txt of=output.txt conv=lcase

Leveraging awk

awk, a versatile text processing tool, offers a succinct way to convert text to lowercase.

$ awk '{ print tolower($0) }' input.txt > output.txt

The Magic of perl

Perl enthusiasts can harness the power of this scripting language to achieve case conversion.

$ perl -pe '$_= lc($_)' input.txt > output.txt

Transforming with sed

For those who appreciate the elegance of sed, this command can seamlessly convert text to lowercase.

$ sed -e 's/\(.*\)/\L\1/' input.txt > output.txt

Converting Text to Uppercase

dd for Uppercase Conversion

Using dd to convert text to uppercase is equally achievable.

$ dd if=input.txt of=output.txt conv=ucase

awk for Uppercase Transformation

awk enthusiasts can employ its capabilities for converting text to uppercase.

$ awk '{ print toupper($0) }' input.txt > output.txt

Uppercase Conversion with perl

Perl's power shines again in transforming text to uppercase.

$ perl -pe '$_= uc($_)' input.txt > output.txt

sed for Uppercase Conversion

Converting text to uppercase using sed is both efficient and effective.

$ sed -e 's/\(.*\)/\U\1/' input.txt > output.txt