Ansible ad-hoc temporary command

ad-hoc What is it?

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ad-hoc In short " Provisional order ", The execution is over , Not saved , That is, the execution of a module is over , If you want her to run over and over again , No way. . Unlike writing multiple commands to a file , It can be run over and over again .

• Application scenarios 1∶ Check whether the processes of multiple nodes exist
• Application scenarios 2∶ Copy the specified file to the local

[[email protected] ~]# ansible webservers -m shell -a "ps -aux | grep nginx" -i /etc/ansible/hosts

[[email protected] ~]# ansible webservers -m shell -a "touch /root/ansible.txt" -i /etc/ansible/hosts

ad-hoc Command to use

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Order sample ∶ansible  'groups'  -m  command  -a  'df -h', The meaning is shown in the figure below ;

shell Modules can actually solve many problems , But this module is definitely not enough , and shell Module cannot guarantee idempotency , Other modules also contain other functions .

ad-hoc Execution process

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1. Load your own profile , Default /etc/ans1b1e/ansible.cfg
2. Find the corresponding host configuration file , Find the host or group to execute
3. Load the corresponding module file , Such as command
4. adopt ansible Generate the module or command corresponding to the temporary py file , And transfer the file to the remote server for corresponding execution user $HOME/.ansible/tmp/ansible-tmp-nurber/XX.PY（ This file is invisible , It is deleted after execution ）（ The controlled end is called Python To resolve this temporary py file , And then call shell To run , It is deleted after running ）
5. Execute the... Of the user's home directory ` file
6. Give the papers +x perform
7. Execute and return results
8. Delete temporary py file ,sleep 0 sign out

[[email protected] ~]# ansible webservers -m shell -a "sleep 10" -i /etc/ansible/hosts 

[[email protected] tmp]# ls ansible-tmp-1656102874.99-71725-64844177037053/
AnsiballZ_command.py
[[email protected] tmp]# pwd
/root/.ansible/tmp

ad-hoc Execution status

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Use ad-hoc Execute a remote command , Notice the color of the returned result ;

• green ∶ Represents that the managed end host has not been modified
• yellow ∶ On behalf of the managed end host, changes are found
• Red ： It means something's wrong , Pay attention to the tips

Demonstrate creating a project and using ad-hoc

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[[email protected] ~]# mkdir -p project
[[email protected] ~]# cd project/
[[email protected] project]# cp /etc/ansible/ansible.cfg .
[[email protected] project]# cp /etc/ansible/hosts .
[[email protected] project]# ls
ansible.cfg  hosts

  Now the configuration read by the project is /root/project/ansible.cfg

[[email protected] project]# ansible --version
ansible 2.9.27
  config file = /root/project/ansible.cfg
  configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.5 (default, Nov 16 2020, 22:23:17) [GCC 4.8.5 20150623 (Red Hat 4.8.5-44)]

[[email protected] project]# vim ansible.cfg 
inventory      = /root/project/hosts  # The absolute path can be written here , You can also write relative paths /hosts

  Here you can also adjust forks,1 On behalf of one by one execution ,5 On behalf of concurrent execution 5 platform

forks          = 5   # Adjust the number of parallel hosts 

This parameter can be increased during optimization , Adjust the number of machines to the number of machines , This will make the execution effect faster , Or one by one

[[email protected] project]# ansible webservers -m shell -a "sleep 3" -f 1
192.168.111.6 | CHANGED | rc=0 >>

192.168.111.7 | CHANGED | rc=0 >>

192.168.111.8 | CHANGED | rc=0 >>


[[email protected] project]# ansible webservers -m shell -a "sleep 3" -f 5
192.168.111.8 | CHANGED | rc=0 >>

192.168.111.7 | CHANGED | rc=0 >>

192.168.111.6 | CHANGED | rc=0 >>

Ansible Common modules

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ansible There are many modules , Although there are many modules , But the most commonly used modules are 20-30 about

Commonly used ad-hoc： modular ：
    0. test                     shell  | command
    0. download                     get_url
    1. install                     yum  | yum_repository
    2. To configure                     copy | template
    3. initialization                 file                 create a file , Create directory , to grant authorization
    4. user | Group                 user   group 
    4. start-up                     systemd 
    6. mount                     mount
    7. Timing task                 cron
    8. A firewall                 firewalld | iptables
    9. File content modification             lineinfile