1.Playbook's initial understanding of scripts

1. What is a playbook? Playbook is translated as a "play". The playbook consists of

play: Defines the role task of the host: Defines the specific task playbook: consists of one or more plays that can contain multiple task tasks
Simple understanding: use different modules to accomplish one thing

2. Advantages of Playbook

1. More functionality than ad-hoc 2. Better control over execution order and dependencies 3. More intuitive syntax 4.ad-hoc cannot be persisted, playbook can be persisted

3. The playbook configuration syntax is described by the yaml syntax and the extension is yaml

• indent
  • YAML uses a fixed indentation style to represent hierarchical structure, where each indentation consists of two spaces and tabs cannot be used
• colon
  • All colons except those ending with a colon must have spaces after them.
• Short Horizontal Line
  • Represents a list item, with a short bar and a space.
  • Multiple items use the same indentation level as the same list.

#playbook example
[root@manager ~]# cat f1.yml
---
- hosts: all
  remote_user: root
  vars:
    file_name: xuliangwei
  tasks:
    - name: Create New File
      file: name=/tmp/{{ file_name }} state=touch
#inspect     
ansible-playbook --syntax-check httpd.yml
#playbook execution
[root@manager ~]# ansible-playbook f1.yml

PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [Using variables] *******************************************************************************************************************************
changed: [10.0.0.30]

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=2    changed=1    unreachable=0    failed=0

Playbook execution results return color status

2.Playbook variable use

Playbook defines variables in three ways

1. Define variable assignment in playbook's yaml file

#Definition in playbook
[root@manager ~]# cat f2.yml
- hosts: all
  vars:  #Define Variables
    file_name: bgx_yaml_vars

  tasks:
  - name: # {{file_name}} refers to the variable defined above
    file: path=/tmp/{{ file_name }} state=touch
    
    
#playbook, create bgx_yaml_vars file in / tmp directory
[root@manager ~]# ansible-playbook f1.yml

2. --extra-vars execution parameters assign to variables

#Reference variable in playbook
[root@manager ~]# cat f3.yml
- hosts: all

  tasks:
  - name: Create New File
    file: path=/tmp/{{ file_name }} state=touch

#The playbook executes by passing in the parameter of the file_name variable, creating the bgx_extra-vars file in the / tmp directory
[root@manager ~]# ansible-playbook f2.yml --extra-vars "file_name=bgx_extra-vars"

3) Define a variable in the file: you can define it in the / etc/ansible/hosts host group, then use palybook to schedule the variable

#Define variables in files
[root@manager ~]# cat /etc/ansible/hosts
[nfs]
10.0.0.20
[nfs:vars]
file_name=bgx_filename

#Call the variable in Playbook
[root@manager ~]# cat f4.yml
---
- hosts: all

  tasks:
  - name: Create New File
    file: path=/tmp/{{ file_name }} state=touch

#playbook, create bgx_filename file in / tmp directory

If the variables defined are duplicated and cause conflicts, the priority is as follows:

3.Playbook variable registration

1) Register variables: The register keyword stores the output of the specified command into a custom variable

[root@manager ~]# cat f5.yml
---
- hosts: all
  tasks:
    - name:
      shell: netstat -lntp
      register: System_Status

    - name: Get System Status
      debug: msg={{System_Status.stdout_lines}}

#playbook execution results
[root@manager ~]# ansible-playbook f5.yml
PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [shell] ******************************************************************************************************************************
changed: [10.0.0.30]

TASK [Get System Status] ******************************************************************************************************************
ok: [10.0.0.30] => {
    "msg": [
        "tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      925/sshd            ",
        "tcp6       0      0 :::22                   :::*                    LISTEN      925/sshd            "
    ]
}

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=3    changed=1    unreachable=0    failed=0

4.Playbook conditional statements

Conditional judgment statements in playbook use when

[root@manager ~]# cat f6.yml
- hosts: all
  remote_user: root
  tasks:
    - name: Create File
      file: path=/tmp/this_is_{{ ansible_hostname }}_file state=touch
      when: (ansible_hostname == "nfs") or (ansible_hostname == "backup")

#Only when the system is centos's host will it execute
    - name: Centos Install httpd
      yum: name=httpd state=present
      when: (ansible_distribution == "CentOS")

#Only if the system is a ubuntu host will it execute
    - name: Ubuntu Install httpd
      yum: name=httpd2 state=present
      when: (ansible_distribution == "Ubuntu")


#playbook execution results:
[root@manager ~]# vim f6.yml
[root@manager ~]# ansible-playbook f6.yml

PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [Create File] ************************************************************************************************************************
skipping: [10.0.0.30]  #Host name mismatch is skipped and matching creates a file

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=1    changed=0    unreachable=0    failed=0

5.Playbook Loop Statement

1. Standard Reuse Scenario - Bulk Installation Software

[root@manager ~]# cat f7.yml
---
- hosts: all
  remote_user: root
  tasks:
    - name: Installed Pkg
      yum: name={{ item }} state=present
      with_items:
        - wget
        - tree
        - lrzsz


#palybook execution results
[root@manager ~]# ansible-playbook  f7.yml

PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [Installed Pkg] **********************************************************************************************************************
ok: [10.0.0.30] => (item=[u'wget', u'tree', u'lrzsz'])

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=2    changed=0    unreachable=0    failed=0

2. Standard reuse scenarios - creating users in bulk

[root@manager ~]# cat f7.yml
- hosts: all
  remote_user: root
  tasks:
    - name: Add Users
      user: name={{ item.name }} groups={{ item.groups }} state=present
      with_items:
        - { name: 'testuser1', groups: 'bin' }
        - { name: 'testuser2', groups: 'root' }


#palybook execution results
[root@manager ~]# ansible-playbook f7.yml
PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [Add Users] **************************************************************************************************************************
changed: [10.0.0.30] => (item={u'name': u'testuser1', u'groups': u'bin'})
changed: [10.0.0.30] => (item={u'name': u'testuser2', u'groups': u'root'})

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=2    changed=1    unreachable=0    failed=0

3. Standard reuse scenarios - Copy multiple directories

[root@manager ~]# cat f7.yml
- hosts: all
  remote_user: root
  tasks:
    - name: Configure Rsync Server
      copy: src={{ item.src }} dest=/etc/{{ item.dest }} mode={{ item.mode }}
      with_items:
        - {src: "rsyncd.conf", dest: "rsyncd.conf", mode: "0644"}
        - {src: "rsync.passwd", dest: "rsync.passwd", mode: "0600"}

6.Playbook exception handling

The default Playbook checks the return status of commands and modules and interrupts playbook execution if an error occurs, adding parameters: ignore_errors: yes Ignores errors

[root@manager ~]# cat f9.yml
---
- hosts: all
  remote_user: root
  tasks:
    - name: Ignore False
      command: /bin/false
      ignore_errors: yes

    - name: touch new file
      file: path=/tmp/bgx_ignore state=touch

Skip errors during playbook

[root@manager ~]# ansible-playbook f9.yml

PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [Ignore False] ***********************************************************************************************************************
fatal: [10.0.0.30]: FAILED! => {"changed": true, "cmd": ["/bin/false"], "delta": "0:00:00.002819", "end": "2018-11-13 07:22:47.301758", "msg": "non-zero return code", "rc": 1, "start": "2018-11-13 07:22:47.298939", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}
...ignoring

TASK [touch new file] *********************************************************************************************************************
changed: [10.0.0.30]

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=3    changed=2    unreachable=0    failed=0

7.Playbook tags Tags

1. Labeling
Label an object One object Many labels One label many objects

2. Tag usage, bundled by tags and task objects, controls partial or specified task execution

[root@manager ~]# cat f10.yml
---
- hosts: all
  remote_user: root
  tasks:
    - name: Install Nfs Server
      yum: name=nfs-utils state=present
      tags:
        - install_nfs
        - install_nfs-server

    - name: Service Nfs Server
      service: name=nfs-server state=started enabled=yes
      tags: start_nfs-server
    
#Perform playbook normally
[root@manager ~]# ansible-playbook  f10.yml

PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [Install Nfs Server] *****************************************************************************************************************
ok: [10.0.0.30]

TASK [Service Nfs Server] *****************************************************************************************************************
ok: [10.0.0.30]

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=3    changed=0    unreachable=0    failed=0

Use -t to specify tags to execute, multiple tags separated by commas

[root@manager ~]# ansible-playbook -t install_nfs-server f10.yml

PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [Install Nfs Server] *****************************************************************************************************************
ok: [10.0.0.30]

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=2    changed=0    unreachable=0    failed=0

Use --skip-tags to exclude tags that are not executed

[root@manager ~]# ansible-playbook --skip-tags install_nfs-server f10.yml

PLAY [all] ********************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************
ok: [10.0.0.30]

TASK [Service Nfs Server] *****************************************************************************************************************
ok: [10.0.0.30]

PLAY RECAP ********************************************************************************************************************************
10.0.0.30                  : ok=2    changed=0    unreachable=0    failed=0

8.Playbook Handlers

playbook Install Apache Example

[root@m01 ~]# cat webserver.yml 
- hosts: web
  remote_user: root
#1. Define variables and call them in the configuration file
  vars:
    http_port: 8881

#2. Install the httpd service
  tasks:
    - name: Install Httpd Server
      yum: name=httpd state=present

#3. Using the template, reference the variables defined by vars above to the configuration file
    - name: Configure Httpd Server
      template: src=./httpd.conf dest=/etc/httpd/conf/httpd.conf
      notify: Restart Httpd Server

#4. Start the Httpd service
    - name: Start Httpd Server
      service: name=httpd state=started enabled=yes

#5. Check the current running port status of the Httpd service
    - name: Get Httpd Server Port
      shell: netstat -lntp|grep httpd
      register: Httpd_Port

#6. Output the status of Httpd running to the panel
    - name: Out Httpd Server Status
      debug: msg={{ Httpd_Port.stdout_lines }}
      ignore_errors: yes

#6. If the configuration file changes, the module below the handlers will be called
  handlers:
    - name: Restart Httpd Server
      service: name=httpd state=restarted

9.Playbook Include

Include is used to dynamically include the tasks task list, include_tasks new/old

include Call Task Method

#Main Entry File
[root@mha ~]# cat main.yml
- hosts: all
  remote_user: root
  tasks:
    - include_tasks: f20.yml
    - include_tasks: f21.yml

#f20.yml
[root@mha ~]# cat f20.yml
- name: create file1
  command: touch file1

#21.yml
[root@mha ~]# cat f21.yml
- name: create file2
  command: touch file2