Ansible Playbook Detailed

The previous article introduced the installation configuration and example of Ansible: http://msiyuetian.blog.51cto.com/8637744/1748143

The following article mainly introduces Ansible's playbook, playbook is equivalent to the module or function written into the configuration file, and then we execute the configuration file to achieve the purpose of remote operation and maintenance automation.

First, the simple use of playbook

1. Create a File instance

1) Edit the configuration file

[Email protected] ~]# cd/etc/ansible/

[[email protected] ansible]# VIM test.yml//fixed suffix is yml, be sure to note the space

--- -Hosts:testhost User:root Tasks -Name:playbook_test Shell:touch/tmp/playbook.txt

Attention:

The hosts parameter specifies which hosts are to be used for the reference;

The user parameter specifies what users are using to log on to the remote host operation;

tasks specifies a task whose name parameter is also a description of the task, which is printed during execution.

2) Execute the configuration file

[Email protected] ansible]# Ansible-playbook test.yml

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3) Remote machine view

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2. Create a User instance

1) Edit the configuration file

[Email protected] ansible]# vim create_user.yml

--- P>-name:create_user   user:root   gather_facts:false    -User: "Msiyuetian"   tasks:       User:name= "{{user}}"

Attention:

The name parameter provides an overview of the functionality implemented by the playbook, which prints the value of the name variable, which can be omitted, during subsequent execution;
The gather_facts parameter specifies whether to execute the Setup module to obtain host-related information before the following task section executes, which is used when the subsequent task uses the information obtained by Setup;
The VARs parameter specifies a variable, which refers to a user variable whose value is test, and it is important to note that the value of the variable must be quoted in quotation marks;
User has set the call to the user module, name is a parameter in the user module, and the added user name calls the value of the above username.

2) Execute the configuration file

[Email protected] ansible]# Ansible-playbook create_user.yml

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3) Remote machine view

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Second, Playbook cycle

Example: Modifying 1.txt and 2.txt file properties under the/tmp/directory

1) New Experiment file

# Touch/tmp/{1.txt,2.txt}//Operate on all hosts in the Testhost group

2) Edit the configuration file

[Email protected] ansible]# vim loop.yml

--- -hosts:testhost   tasks: Span style= "font-family: ' Microsoft Jas Black ', ' Microsoft Yahei ';" >   -Name:change mode for files       file:path=/tmp/{{Item}} mode=600 owner=root group=root       With_items:        -1.txt        - 2. txt

3) Execute the configuration file

[Email protected] ansible]# Ansible-playbook loop.yml

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4) Remote Viewing effect

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Note: you can see that the permissions are 600, and the primary and the group are root.

Three, playbook condition judgment

Conditional judgments are generally used for different versions of the system, such as CentOS, Ubuntu and other systems to operate different commands.

1) Edit the configuration file

[Email protected] ansible]# vim when.yml

--- P>-hosts:testhost   gather_facts:true   tasks:       Shell:touch/tmp/when.txt       When:facter_ipaddress = = "192.168.0.110"

Note: The specified file is only created on the machine when the parameter facter_ipaddress is 192.168.0.110, which means that only the specific hosts in the Testhost group are operating, ignoring the other hosts in the group. We can see the values of each parameter by the following command:

[Email protected] ansible]# ansible testhost-m Setup

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2) Execute the configuration file

[Email protected] ansible]# Ansible-playbook when.yml

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3) Remote Viewing effect

[Email protected] ~]# ll/tmp/

650) this.width=650; "src=" Http://s2.51cto.com/wyfs02/M01/7D/90/wKiom1bqngfAQdCWAAAyv1BETps216.png "title=" 17.png "alt=" Wkiom1bqngfaqdcwaaayv1betps216.png "/>

Iv. Playbook Handlers

After we perform the tasks, we have to perform some actions after the server has changed. For example, if we modify the configuration file of a service, we need to restart the service. Examples are as follows:

1) Edit the configuration file

[Email protected] ansible]# vim handlers.yml

--- -Name:handlers Test Hosts:testhost User:root Tasks -Name:test Copy COPY:SRC=/ETC/PASSWD Dest=/tmp/handlers.txt Notify: Test handlers Handlers: -Name: Test Handlers Shell:echo "msiyuetian.blog.51cto.com" >>/tmp/handlers.txt

Note: only the copy module is actually executed, it will call the following handlers related operation, append content. That is, if the SRC and dest contents are the same, the shell-related commands inside the handlers will not be executed. Therefore, this comparison is appropriate after the configuration file changes, the need to restart the service operation.

2) Execute the configuration file

[Email protected] ansible]# Ansible-playbook handlers.yml

650) this.width=650; "src=" Http://s2.51cto.com/wyfs02/M00/7D/90/wKiom1bqpgOwpY1LAABD9Vta2RA227.png "title=" 18.png "alt=" Wkiom1bqpgowpy1laabd9vta2ra227.png "/>

3) Remote Viewing effect

[Email protected] ~]# Cat/tmp/handlers.txt

650) this.width=650; "src=" Http://s4.51cto.com/wyfs02/M01/7D/90/wKiom1bqpn2jmQx2AACCE8D_WZw053.png "title=" 19.png "alt=" Wkiom1bqpn2jmqx2aacce8d_wzw053.png "/>

The copy file can be viewed successfully, and the relevant commands for handlers are executed, and new information is appended.

This article is from the "M April Days" blog, please be sure to keep this source http://msiyuetian.blog.51cto.com/8637744/1752326

Ansible Playbook Detailed