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diff --git a/ansible.html.markdown b/ansible.html.markdown index cd619cc3..2eb6df2e 100644 --- a/ansible.html.markdown +++ b/ansible.html.markdown @@ -6,17 +6,38 @@ contributors: filename: LearnAnsible.txt --- -Ansible is (one of the many) orchestration tools. It allows you to controll your environment (infrastructure and a code) and automate the manual tasks. -'You can think as simple as writing in bash with python API :) -Of course the rabit hole is way deeper.' +```yaml +--- +Ansible - the easiest orchestration tool -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...) +Why Ansible and Intro - in the second part of document +``` -## Ansible naming and basic concept +## Installation +```bash +# Universal way +$ pip install ansible -### Basic ansible commands +# Debian, Ubuntu +$ apt-get install ansible +``` +* Appendix A - How do I install ansible +[Additional Reading.](http://docs.ansible.com/ansible/latest/intro_installation.html) + +### Basic ansible commands (shell execution) +```bash +# This command ping the localhost (defined in default inventory /etc/ansible/hosts) + +$ ansible -m ping localhost +<span style="color:green">localhost | SUCCESS => { + "changed": false, + "ping": "pong" +}</span> + +``` +### Commands There are few commands you should know about `ansible` (to run modules in CLI) @@ -25,16 +46,37 @@ There are few commands you should know about `ansible-galaxy` (to install roles from github/galaxy) and other! +```bash +$ ansible -m shell -a 'date; whoami' localhost #hostname_or_a_group_name +``` + +The module `command` allows to execute a single command. It will not be processed through the shell, so variables like $HOME and operations like "<", ">", "|", ";" and "&" will not work. Use shell :) +We should also mention a module `raw` that sometimes can save the day. + +```bash +$ ansible -m command -a 'date; whoami' # FAILURE + +$ ansible -m command -a 'date' +$ ansible -m command -a 'whoami' +``` + + +#### Module - program (usaly python) that execute, do some work and return proper output :) +This program perform specialized task/action (like manage instances in the cloud, execute shell command). +The simplest module is called `ping` - it just returns a JSON with `pong` message. + +Example of modules: +Module: `shell` - a module that executes shell command on a specified host(s). +Module: `file` - performs file operations (stat, link, dir, ...) + + +```yaml +``` + #### Inventory Inventory is a set of objects/hosts against which we are executing our playbooks For this few minutes, lets asume that we are using default ansible inventory (which in Debian based system is placed in /etc/ansible/hosts_ -#### Module - this is name for an logical program (usaly python) that consume proper JSON input and return proper output :) -This program perform certain task/action (like manage Amazon instances, execute shell command, any of your program). -The simplest module is called `ping` - it just returns a JSON with `pong` message and ansible variables. -Example: Module:shell - a module that executes shell command on a delegated host(s). -Example: Module:file - performs file operations (stat, link, dir, ...) - ##### Task Execution of a single module is called a `task` @@ -44,30 +86,22 @@ Another example of the module that allow you to execute command remotly on multi Example of a Task run in CLI: ###### Run a ansible module -```bash -$ ansible -m ping hostname_or_a_group_name -$ ansible -m shell -a 'date; whoami' hostname_or_a_group_name -``` - -another module - `command` that allows to execute a single command only with a simple shell #JM -We should also mention a module `raw` - -```bash -$ ansible -m command -a 'date; whoami' # FAILURE - -$ ansible -m command -a 'date' -$ ansible -m command -a 'whoami' -``` ##### Playbook - -A common way to execute tasks is called `playbook`. -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). +Execution plan written in a form of script file(s) is called `playbook`. +Playbook consist of multiple elements +* a list (or group) of hosts that 'the play' is executed against +* `task(s)` or `role(s)` that are going to be executed +* multiple optional settings (like default variables, and way more) Playbook script language is YAML -You can think that it is very advanced CLI script that you are executing. +You can think that playbook is very advanced CLI script that you are executing. + -Example of the playbook: +##### Example of the playbook: +This playbook would execute (on all hosts defined in the inventory) two tasks +*`ping` that would return message *pong* +* `shell` that execute three commands and return the output to our terminal ```yml hosts: all @@ -83,7 +117,7 @@ You can execute a playbook with a command: ```bash $ ansible-playbook path/name_of_the_playbook.yml ``` - +It is also possible to become a user other than root using --become-user: ## More on ansible concept ### ansible-roles (a 'template-playbooks in right structure') @@ -138,6 +172,9 @@ It is a best way to restart a service, check if application port is open, etc. ### ansible - variables lookup's +#### templates +JINJA2 + ### ansible-vault ### inventory @@ -180,6 +217,14 @@ tags meta no_logs +## Introduction +Ansible is (one of the many) orchestration tools. It allows you to controll your environment (infrastructure and a code) and automate the manual tasks. +'You can think as simple as writing in bash with python API :) +Of course the rabit hole is way deeper.' + +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...) + + ## Main cons and pros |