Introduction to Ansible

• Ansible can manage both Linux for Redhat s, Linux for Debian, and Windows hosts.The management node only connects to the remote host while executing the script, and there is no special synchronization mechanism, so exceptions such as power outages generally do not affect ansbile.

• Ansible is a new automated operation and maintenance tool. It is developed based on Python and combines the advantages of many operation and maintenance tools (puppet, cfengine, chef, func, fabric). It realizes the functions of batch system configuration, batch program deployment, batch running commands and so on.Ansible is module-based and does not have the capability to deploy in bulk.What really has a bulk deployment is the modules that ansible runs, and Ansible only provides a framework.Mainly include:
  1. connection plugins: responsible and monitored for communication;
  2. host inventory: The host for the specified operation is the host for which monitoring is defined in the configuration file;
  3. Various module core modules, command modules, custom modules;
  4. With the help of plug-in, logging of log messages and other functions can be completed;
  5. playbook: When a script performs multiple tasks, it is not necessary for a node to run multiple tasks at once.

• Ansible's architecture: connect to other hosts Using ssh protocol by default

Ansible Environment Installation Deployment

• Install epel source

yum install -y epel-release

• Install Ansible Service

yum install ansible -y

• View the Ansible version

ansible --version

• Install tree Service

yum install tree -y

• Tree structure display folder

tree /etc/ansible/

/etc/ansible/
├── ansible.cfg    #ansible configuration file
├── hosts         #ansible's main repository for storing information about remote hosts that need to be managed
└── roles

• Switch Ansible working directory

cd /etc/ansible

• Configure host list

vim hosts
[webserver]
192.168.142.121
[mysql]
192.168.142.122

• Configure key pair validation

ssh-keygen -t rsa

• Key pair transfer

ssh-copy-id root@192.168.142.121
ssh-copy-id root@192.168.142.122

Ansible command line module

• command module

Command format:

ansible [host] [-m module] [-a args]

#List all installed modules Note: Quit by q
ansible-doc -l

#-s Lists yum module description information and action
ansible-doc -s yum

- View the other party's system time

#Specify ip execution date
ansible 192.168.142.121 -m command -a 'date'

#Specify Category Execution date
ansible webserver -m command -a 'date'

#Exempt from interactive execution date
ansible mysql -m command -a 'date' 

#All hosts host execute date command
ansible all -m command -a 'date'

#Run command module by default if -m module is not added
ansible all -a 'ls /'

• cron module

Two state s: press adds (can be omitted), absent removes

#View cron module information
ansible-doc -s cron

#Create planned tasks
ansible webserver -m cron -a 'minute="*/1" job="/bin/echo heihei" name="test cron job"'

#View planned tasks
ansible webserver -a 'crontab -l'

#Remove the scheduled task, name=None if it is not named
ansible webserver -m cron -a 'name="test cron job" state=absent'  

• user module

The user module is requesting three instructions: useradd, userdel, usermod

#View user module information
ansible-doc -s user

#Create user test01
ansible mysql -m user -a 'name="test01"'

#View user information
ansible mysql -m command -a 'tail /etc/passwd'

#Delete user test01
ansible mysql -m user -a 'name="test01" state=absent'

• group module

The group module requests three instructions: groupadd, groupdel, groupmod

#View group module information
ansible-doc -s group

#Create Group
ansible mysql -m group -a 'name=mysql gid=306 system=yes'
ansible mysql -a 'tail /etc/group'

#Create user and add to group
ansible mysql -m user -a 'name=test01 uid=306 system=yes group=mysql'

#View user information
ansible mysql -a 'tail /etc/passwd'
ansible mysql -a 'id test01'   

• copy module

#View copy module information
ansible-doc -s copy

#Copy Files
ansible mysql -m copy -a 'src=/etc/fstab dest=/opt/fstab.back owner=root mode=640'

#View opt directory
ansible mysql -a 'ls -l /opt'

#View fstab.back file
ansible mysql -a 'cat /opt/fstab.back'

#Write hello heihei! To/opt/fstab.back
ansible mysql -m copy -a 'content="hello heihei!"
dest=/opt/fstab.back'

#View the fstab.back file again
ansible mysql -a 'cat /opt/fstab.back' 

• file module

#View file module information
ansible-doc -s file

#Create User
ansible mysql -m user -a 'name=mysql system=yes'

#Create Group
ansible mysql -m user -a 'name=mysql system=yes'

#Modify file ownership group permissions, etc.
ansible mysql -m file -a 'owner=mysql group=mysql mode=644 path=/opt/fstab.back'

#Link file to set/opt/fstab.link to/opt/fstab.back
ansible mysql -m file -a 'path=/opt/fstab.link src=/opt/fstab.back state=link'

#Delete a file
ansible mysql -m file -a "path=/opt/fstab.back state=absent"      

#Create a file
ansible mysql -m file -a "path=/opt/test state=touch"             

• ping module

#View ping module information
ansible-doc -s ping

#Test whether the managed host is online 
ansible all -m ping

- service Modular 

#View service module information
ansible-doc -s service

#Install httpd service
yum install -y httpd

#View the web server httpd status
ansible webserver -a 'systemctl status httpd'        

#service httpd start
ansible webserver -m service -a 'enabled=true name=httpd state=started'

#Check to see if it's turned on
systemctl status httpd

• shell module

#View shell module information
ansible-doc -s shell

#Create user Password for user using no interactive mode
ansible mysql -m shell -a 'echo abc123|passwd --stdin mysql'      

• script module

#View script module information
ansible-doc -s script

#Loop script
vim test.sh
#!/bin/bash
echo "hello ansible from script"> /opt/script.txt

#Give Execution Permission
chmod +x test.sh

#Execute script
ansible mysql -m script -a 'test.sh'

#View on other hosts
cat /opt/script.txt

• yum module

#View yum module information
ansible-doc -s yum

#yum install zsh
ansible mysql -m yum -a 'name=zsh'
rpm -q zsh

#Uninstall zsh
ansible mysql -m yum -a 'name=zsh state=absent'
rpm -q zsh

• setup module

#View setup module information
ansible-doc -s setup

#Get facts information for mysql group host
ansible mysql -m setup