Session 9

IaaS Automation: Ansible

Is the name given to the general process of managing a changing software system

What is Configuration Management?

Support the system integration process so that all developers can:
- access the project code and documents in a controlled way
- find out what changes have been made
- compile and link components to create a system

The aim of configuration management is to

(Continuous Integration/Continuous Delivery)

What does CI/CD stands for?

To be fully automated, with each run fully logged and visible to the entire team

The main goal of the CI/CD processes is

The bits and pieces of a microservices-based application to evolve and mature individually, reducing blockers.

CI/CD allows

- continuous integration
- continuous delivery
- continuous deployment

The CI/CD pipeline involves

Cloud-native companies adopted a fairly extreme approach of

continuously improving their online services by having a fully automated process for building, testing, and deploying new code

The pipeline run is triggered by

a source code repository

The Build stage on CI/CD includes

The compilation of programs written in languages such as Java, C/C++, and Go

In the CI/CD Test stage, automated tests are run in order to

Validate the code and the application behavior.

Why is the Test stage an important stage?

Because it acts as a “safety net” to prevent easily reproducible bugs from being introduced.

Depending on the size and complexity of the project, the Test phase can last from

seconds to hours

What is Ansible?

is an open-source IT automation/ a configuration management tool

What does Ansible automates?

- Application deployment
- Cloud provisioning
- Configuration management
- configuration of multiple servers/networks/clouds

Who created Ansible?

Michael DeHaan

In witch year was ansible created?

2012

In witch language is Ansible written?

Python and Powershell

How does Ansible automates configuration?

By the use of Ansible playbooks

What are playbooks?

Ansible configuration, deployment and orchestration language, written in YAML

The ansible inventory file defines

The hosts and groups of hosts upon which commands, modules, and tasks in a playbook operate

What does Agentless means?

No client / server concept

What are some ansible features?

- Simple to setup
- Declarative
- Idempoten

What does declarative means?

that a playbook does not require any knowledge of the current state of the server, only its desirable state

What does idempotent means?

That running the same "playbook" multiple times producces the same output/configuraiton

ssh-keygen is used to

Generate private and public keys on the control node

What command can you use to send public key to the ~/.ssh/authorized_keys file in the target node user home directory?

ssh-copy-id user@remotehost

What is the ansible command?

The main Ansible command to run ad-hoc commands on remote nodes

What is the ansible-playbook command?

A command to run playbooks

What is the ansible-pull command?

The main Ansible pull command

What is the ansible-doc command?

The ansible documentation program

What is the ansible-galaxy command?

An ansible Galaxy interaction program

What is the ansible-vault command?

The Ansible password vault

What is the ansible-inventory command?

A command to display or dump the inventory

What is the ansible-console command?

The Ansible interactive console against a chosen inventory

What is the ansible-config command?

A command to view, edit and manage configuration

How do you Transfer a file directly to multiple servers with Ansible?

ansible -i hosts local -m copy -a "src=/etc/hosts dest=/tmp/hosts"

How do you change ownership and permissions on files with Ansible?

ansible -i hosts local -m file -a "dest=/ansible/a.txt mode=600 owner=instructor group=instructor"

How do you delete directories (recursively) and delete files with Ansible?

ansible -i hosts local -m file -a "dest=/path/to/dir state=absent“

How do you ensure a package is installed, but don’t update it with ansible?

ansible -i hosts local -m apt -a "name=acme state=present"

You use -m on ansible to

Select an Ansible module to run the command against

you use -a on ansible to

provide options to the selected module

How do you ensure a package is at the latest version with ansible?

ansible -i hosts local -m apt -a "name=acme state=latest"

How do you ensure a package is not installed with ansible?

ansible -i hosts local -m apt -a "name=acme state=absent"

How do you create or manipulate an existing user account with ansible?

ansible all -m user -a "name=student password="

How do you gather discovered vars about remote hosts with ansible?

ansible all -m setup

How do you ensure a service is started on all web servers with ansible?

ansible -i hosts webservers -m service -a "name=httpd state=started"

How do you restart a service on all web servers with ansible?

ansible webservers -m service -a "name=httpd state=restarted"

How do you ensure a service is stopped with ansible?

ansible webservers -m service -a "name=httpd state=stopped“

How do you create a directory with ansible?

ansible local -i hosts -m ansible.builtin.file -a "path=/tmp/testfile1 state=touch mode=700"