The role of Ansible10:playbook and the inclusion of "go"

When a single playbook file becomes larger, we need to reorganize the playbooks. We can split a large playbook into several small playbook files, and then include them in the main configuration file, which is called the inclusion of a playbook. We can also follow certain rules to carry out a certain type of task in a directory, and in this directory again to the playbook according to Tasks,handlers,files,templates,vars and other types into several files, The corresponding file is stored in the corresponding directory, this organization is called Playbook's roles.

First, the inclusion of playbook

The inclusion of playbook is actually the use of the Include keyword

1. Tasks include

Example 1:

A task file Foo.yml example is as follows:

# possibly saved as Tasks/foo.yml

-Name:placeholder foo

Command:/bin/foo

-Name:placeholder Bar

Command:/bin/bar

Include foo.yml in another task file Bar.yml:

Tasks

-Include:tasks/foo.yml

You can also bring variables into the include:

Tasks

-Include:wordpress.yml User=timmy

-Include:wordpress.yml User=alice

-Include:wordpress.yml User=bob

The variables are brought into the following ways:

Tasks

-{include:wordpress.yml, user:timmy, Ssh_keys: [' keys/one.txt ', ' Keys/two.txt ']}

Give one more example:

Tasks:-Include:wordpress.yml vars:remote_user:timmy some_list_variable:-alpha- Beta-gamma

2. Handlers contains

Handlers contains broadly similar to the inclusion of tasks, giving examples directly:

HANDLERS1.YML content is as follows:

# This might is in a file like Handlers/handlers.yml

-Name:restart Apache

Service:name=apache state=restarted

HANDLERS.YML contains handlers1.yml examples:
Handlers:

-Include:handlers/handlers.yml

3. Mixed inclusions

The include can also be used to import one playbook into another playbook:

-Name:this is a play on the top level of a file

Hosts:all

Remote_user:root

Tasks

-Name:say Hi

Tags:foo

Shell:echo "Hi ..."

-Include:load_balancers.yml

-Include:webservers.yml

-Include:dbservers.yml

Ii. Role (roles)

1. Create role

The steps to create a role are as follows:

1) Create a directory with the roles command

2) Create a directory named for the role name in the roles directory, such as Websrvs, etc.

3) files, handlers, meta, tasks, teamplates, and VARs directories are created in each role-named directory, and directories that are not available can be created as empty directories or created.

4) in the Playbook file, call each role

Roles file organization Structure example:

group_vas/

Site.yml

Webservers.yml

roles/

common/

files/

templates/

tasks/

handlers/

vars/

defaults/

meta/

webservers/

files/

templates/

tasks/

handlers/

vars/

defaults/

meta/

Roles the role of each directory and the files available:

Files: Storing a file that is called by a module such as copy or script

Tempaltes:jinja2 template file

Tasks: You should include at least one file named Main.yml that defines the task list for this role, which can use include to include other task files located in this directory

Handlers: Contains at least one main.yml file that defines the various handler used by this role, and the other handler files included with the include in handler should also be located in this directory

VARs: You should include a main.yml file that defines the variables used by this role

Meta: A main.yml file should be included to define the special settings and dependencies for this role

Default: Use some directories when you set defaults for the current role, including a main.yml file

2. Quoting roles

Basic Reference methods:

-Hosts:webservers

Roles

-Common

-Webserver

You can also bring in variables when referenced in the following ways:

-Hosts:webservers

Roles

-Common

-{role:foo_app_instance, dir: '/opt/a ', port:5000}

-{role:foo_app_instance, dir: '/opt/b ', port:5001}

You can also use conditional statements when referencing:

-Hosts:webservers

Roles

-{role:some_role, when: "ansible_os_family = = ' RedHat '"}

Here is an example of a variable that is brought in:

-Hosts:webservers

Roles

-Role:database

database_name: {{db_name}}

Database_user: {{Db_pass}}

-Role:webserver

Live_hostname:web1

Domains

-example.com

-www.example.com

3, Pre_tasks and Post_tasks

If you need to perform certain tasks before or after a role is executed, we can use Pre_tasks and post_tasks to declare it. Pre_tasks is executed before role, while Post_tasks executes after role:

-Name:deply Webservers

Host:webservers

Vars_files:

-Secrets.yml

Pre_tasks:

-Name:update Yum Cache

Yum:update_cache=yes

Roles

-Role:apache

Database_host: {{hostvars.db.ansible_eth0.ipv4.address}}

Domains

-Exampel.com

-www.example.com

Post_tasks:

-Name:print Something

Shell:echo "The roles has been updated!"

4. Role dependence

If the current role needs to rely on another role before execution, we can define a role dependency in main.yml in the Roles meta directory.

Example 1:

#roles/webservers/meta/main.yml

Dependencies

-{Role:common, some_parameter:3}

-{role:apache, port:80}

-{role:postgres, Dbname:blarg, other_parameter:12}

Example 2:

Dependencies

-{ROLE:NTP, ntp_server=ntp.ubuntu.com}

-{Role:web}

-{role:memcached}

5. Ansible Galaxy

Ansible-galaxy is a tool that we can use to quickly create a standard roles directory structure, and use it to download the roles that others have written on the https:/galaxy.ansible.com.

Initialize a roles directory structure by Ansible-galaxy, by using the following method:

Ansible-galaxy Init/etc/ansible/roles/websrvs

Install roles written by someone else:

Ansible-galaxy install-p/etc/ansible/roles Bennojoy.mysql

List the installed roles:

Ansible-galaxy List

To view installed roles information:

Ansible-galaxy Info Bennojoy.mysql

Uninstall roles:

Ansible-galaxy Remove Bennojoy.mysql

This article is from the "Nobody" blog, please be sure to keep this source http://breezey.blog.51cto.com/2400275/1757832

The role of Ansible10:playbook and the inclusion of "go"