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@ -6,17 +6,38 @@ contributors:
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filename: LearnAnsible.txt
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---
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Ansible is (one of the many) orchestration tools. It allows you to controll your environment (infrastructure and a code) and automate the manual tasks.
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'You can think as simple as writing in bash with python API :)
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Of course the rabit hole is way deeper.'
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```yaml
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---
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Ansible - the easiest orchestration tool
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Ansible have great integration with multiple operating systems (even Windows) and some hardware (switches, Firewalls, etc). It has multiple tools that integrate with the could providers. Almost every worth-notice cloud provider is present in the ecosystem (AWS, Azure, Google, DigitalOcean, OVH, etc...)
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Why Ansible and Intro - in the second part of document
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```
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## Ansible naming and basic concept
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## Installation
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```bash
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# Universal way
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$ pip install ansible
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### Basic ansible commands
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# Debian, Ubuntu
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$ apt-get install ansible
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```
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* Appendix A - How do I install ansible
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[Additional Reading.](http://docs.ansible.com/ansible/latest/intro_installation.html)
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### Basic ansible commands (shell execution)
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```bash
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# This command ping the localhost (defined in default inventory /etc/ansible/hosts)
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$ ansible -m ping localhost
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<span style="color:green">localhost | SUCCESS => {
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"changed": false,
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"ping": "pong"
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}</span>
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```
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### Commands
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There are few commands you should know about
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`ansible` (to run modules in CLI)
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@ -25,16 +46,37 @@ There are few commands you should know about
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`ansible-galaxy` (to install roles from github/galaxy)
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and other!
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```bash
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$ ansible -m shell -a 'date; whoami' localhost #hostname_or_a_group_name
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```
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The module `command` allows to execute a single command. It will not be processed through the shell, so variables like $HOME and operations like "<", ">", "|", ";" and "&" will not work. Use shell :)
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We should also mention a module `raw` that sometimes can save the day.
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```bash
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$ ansible -m command -a 'date; whoami' # FAILURE
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$ ansible -m command -a 'date'
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$ ansible -m command -a 'whoami'
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```
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#### Module - program (usaly python) that execute, do some work and return proper output :)
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This program perform specialized task/action (like manage instances in the cloud, execute shell command).
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The simplest module is called `ping` - it just returns a JSON with `pong` message.
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Example of modules:
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Module: `shell` - a module that executes shell command on a specified host(s).
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Module: `file` - performs file operations (stat, link, dir, ...)
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```yaml
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```
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#### Inventory
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Inventory is a set of objects/hosts against which we are executing our playbooks
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For this few minutes, lets asume that we are using default ansible inventory (which in Debian based system is placed in /etc/ansible/hosts_
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#### Module - this is name for an logical program (usaly python) that consume proper JSON input and return proper output :)
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This program perform certain task/action (like manage Amazon instances, execute shell command, any of your program).
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The simplest module is called `ping` - it just returns a JSON with `pong` message and ansible variables.
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Example: Module:shell - a module that executes shell command on a delegated host(s).
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Example: Module:file - performs file operations (stat, link, dir, ...)
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##### Task
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Execution of a single module is called a `task`
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@ -44,30 +86,22 @@ Another example of the module that allow you to execute command remotly on multi
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Example of a Task run in CLI:
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###### Run a ansible module
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```bash
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$ ansible -m ping hostname_or_a_group_name
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$ ansible -m shell -a 'date; whoami' hostname_or_a_group_name
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```
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another module - `command` that allows to execute a single command only with a simple shell #JM
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We should also mention a module `raw`
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```bash
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$ ansible -m command -a 'date; whoami' # FAILURE
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$ ansible -m command -a 'date'
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$ ansible -m command -a 'whoami'
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```
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##### Playbook
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A common way to execute tasks is called `playbook`.
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You have to define a list (or group) of hosts that is executed against, some `task(s)` or `role(s)` that are going to be executed. There are also multiple optional settings (like default variables, and way more).
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Execution plan written in a form of script file(s) is called `playbook`.
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Playbook consist of multiple elements
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* a list (or group) of hosts that 'the play' is executed against
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* `task(s)` or `role(s)` that are going to be executed
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* multiple optional settings (like default variables, and way more)
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Playbook script language is YAML
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You can think that it is very advanced CLI script that you are executing.
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You can think that playbook is very advanced CLI script that you are executing.
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Example of the playbook:
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##### Example of the playbook:
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This playbook would execute (on all hosts defined in the inventory) two tasks
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*`ping` that would return message *pong*
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* `shell` that execute three commands and return the output to our terminal
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```yml
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hosts: all
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@ -83,7 +117,7 @@ You can execute a playbook with a command:
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```bash
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$ ansible-playbook path/name_of_the_playbook.yml
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```
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It is also possible to become a user other than root using --become-user:
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## More on ansible concept
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### ansible-roles (a 'template-playbooks in right structure')
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@ -138,6 +172,9 @@ It is a best way to restart a service, check if application port is open, etc.
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### ansible - variables
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lookup's
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#### templates
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JINJA2
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### ansible-vault
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### inventory
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@ -180,6 +217,14 @@ tags
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meta
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no_logs
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## Introduction
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Ansible is (one of the many) orchestration tools. It allows you to controll your environment (infrastructure and a code) and automate the manual tasks.
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'You can think as simple as writing in bash with python API :)
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Of course the rabit hole is way deeper.'
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Ansible have great integration with multiple operating systems (even Windows) and some hardware (switches, Firewalls, etc). It has multiple tools that integrate with the could providers. Almost every worth-notice cloud provider is present in the ecosystem (AWS, Azure, Google, DigitalOcean, OVH, etc...)
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## Main cons and pros
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