1, Ansible ad hoc command set

1. Ad hoc usage scenario

Ansible provides two ways to complete tasks, one is ad-hoc command, and the other is to write Ansible playbook. After learning playbooks, you can realize where ansible is really powerful.

• Ad hoc pays more attention to solving some simple or temporary tasks in daily work, which is equivalent to the Shell command under the command line of Linux system. The latter is more suitable for solving complex or solidified tasks, which is equivalent to the Shell Scripts of Linux system.
• Usage scenario:
  • Shut down all unnecessary servers
  • Temporarily update Apache or Nginx configuration files

2. Ansible concurrency

Ansible and ansible playbook will fork 5 threads to execute commands concurrently by default. If the number of hosts operating at the same time is large, it can be adjusted to a larger value.
Ansible provides us with a convenient option to -f specify the number of threads. The default is 5
ansible webserver -m ping -f 3**
ansible has many modules. The default is command, that is, command module. We can specify different modules through the - m option.

3 ansible doc usage

Ansible has many modules. Ansible also provides a help description tool ansible doc similar to man function.
Before formally learning the Ansible module, it is necessary to understand the usage of Ansible doc:

• Show all available modules
  ansible-doc -l
• Displays the playbook fragment of the specified module
  ansible-doc -s
• Get yum module help
  ansible-doc yum

4. Operation mode and common parameters of ansible command

Format:

ansible detailed list -m modular -a Module parameters

Common parameters

--version                Display version
-m module                Specify the module. The default is command modular
-v                       Detailed process -vv -vvv More detailed process
--list                   Displays a list of hosts, or you can use--list-hosts
-k                       Prompt input ssh Connection password, default key authentication
-C                       Pre execution detection
-T                       The timeout for executing a command. The default value is 10 s
-u                       Specify the user to execute remotely
-b                       implement sudo Switch identity operation
-become-user=USERNAME    appoint sudo User
-K                       Prompt input sudo password

5 basic color representation of ansible

Green execution succeeded, but no changes were made to the remote host
 Yellow execution succeeded and changes were made to the remote host
 Red execution failed

6 common modules in ansible

command module

Function: execute commands on the remote host. This module is the default module

Common parameters

chdir         Enter the specified directory before executing the command
cmd           Run command assignment
creates       If the file exists, it will not run
removes       If the file exists, it will run
free_form     This parameter does not need to be added to the command executed in the remote host

You can use the command ansible doc command - s to view its parameters and meanings

Example:

chdir means to enter the specified directory before executing the command.
Enter the / etc directory and view the passwd file

creates indicates that no action will be performed when the file exists

Remove means that no action is taken when the file does not exist

Note: many wildcards in Linux are not supported in the command module

shell module

Function: similar to command function

Common parameters

chdir	  Enter the specified directory before executing the command
cmd	      Run command assignment
creates	  If the file exists, it will not run
removes	  Runs if the file exists
free_form	This parameter does not need to be added to the command executed in the remote host
executable	Specifies the execution environment. The default is sh

You can use ansible doc shell - s to view its parameters and meanings

Example:

script module

Function: the script written in the ansible host is executed in the controlled host

Common parameters:

Example:

Write a script, and the script written in the ansible host will be executed in the controlled host;

copy module

Function: copy files from ansible host to controlled host

Common parameters

src	source file
dest	Destination file
owner	Specify destination file owner
group	Specify all destination file groups
mode	Specify destination file permissions
backup=yes	Back up the original file when the file exists in the controlled host
content	The specified text content generates the file directly in the controlled host

Example

fetch module

Function: copy files from controlled host to ansible host, but directory is not supported

Common parameters

src	Source file of controlled host
dest	Native directory
flat	Basic name function

Example

Copying the files of the controlled host to the current directory of the host will generate / controlled host / create file user / file name in the current directory

There are files in node1 host and none in node2

unarchive module

Function: decompression

Common parameters

copy         Default to yes from ansible Copy files from host to controlled host
             Set to no Find from controlled hosts src source file
remote_src   Same function copy And on the contrary
             Set to yes Indicates that the package is on a controlled host
             Set to no Indicates that the package is in ansible host
src          Package path, which can make ansible The host can also make the controlled host
dest         Controlled host directory
mode         File permissions after pressurization <copy=yes>

archive module

Function: compression

Common parameters

path         Package directory name
dest         Claim package file name
format       Packaging format
owner        Specify the person to whom the document belongs
mode         Specify file permissions

hostname module

Role: manage host name

Common parameters

name  Specify host name

cron module

Function: schedule tasks

Common parameters

minute        minute
hour          hour
day           day
month         month
weekday       week
name          Task name
job           Task script or command
disabled      yes Disable scheduled tasks
              no Start scheduled task
state         absent Delete scheduled task

yum module

Function: configure system software warehouse source file

Common parameters

name           Specify warehouse name
baseurl        Specify source path
description    Specify warehouse description
file           Specify warehouse file name
enabled        Enable warehouse
gpgcheck       Is the warehouse inspected gpgkey
state          Default value present establish
               absent For deletion

ansible server3 -m yum -a "name=http://172.25.0.250/rhel7.3/x86_64/dvd/Packages/vsftpd-3.0.2-21.el7.x86_64.rpm state=present"		
//Online installation

ansible server3 -m yum -a "name=/mnt/vsftpd-3.0.2-21.el7.x86_64.rpm state=present"			
//Local installation

ansible server3 -m yum -a "name=httpd state=absent"			
//Uninstall software

dnf module

Function: dnf warehouse and management software in the management system

Common parameters

name	Specify package
state	Specify action
	   present install
	   latest to update
	   absent delete
list	List the specified information, httpd, installed, all,available
disable_gpg_check	Disable gpgkey testing
enablerepo	Specify the source of the installation package
disablerepo	Disable package source

service module

Function: manage system service status

Common parameters

name	Specify the service name
state	Specify the action on the service, started,stoped,restarted,reloaded
enabled	Set whether the service is started,yes Open start,no Start not start

ansible webservers -m service -a "name=httpd state=started" 
//Start service

ansible webservers -m service -a "name=httpd state=restarted"
//Restart service

ansible webservers -m service -a "name=httpd state=stopped
//Out of Service

firewalld module

Function: some services may not be used directly after they are started. You need to set the firewall policy to access them

Common parameters

zone	Fire wall domain
service	Service name
permanent	Permanent effect
state	state
	  enbaled allow
	  disabled refuse
immediate	Effective immediately

user module

Function: the module can help us manage users on the remote host, such as creating users, modifying users, deleting users, and creating key peer-to-peer operations for users

Common parameters

name	A required parameter that specifies the name of the user to operate on
group	Specify the base group where the user resides
gourps	Specify the additional group that the user is in
append	Specifies to add an additional group. The default value is no
shell	Specifies the default for the user shell
uid	Specifies the name of the user uid number
comment	Specifies the user's comment information
state	Specifies whether the user exists on the remote host
	   present establish
	   absent delete
remove	    When deleting a user is to delete the user's home directory, the default value is no
password	This parameter is used to specify the password of the user. But the password is clear text and can be used openssl password -6 'password'Generate encrypted characters
generate_ssh_key	generate sshkey

group module

Function: the group module can help us manage groups on remote hosts.

Common parameters

name	A required parameter that specifies the name of the user to operate on
state	Specifies the status of the group
	  present establish
	  absent delete
gid	Used to specify the name of the group gid

lineinfile module

path	Specify the file to operate on
line	Specify text content
regexp	Use regular expressions to match the corresponding lines when replacing text,If multiple lines of text can be matched,Only the last line of text that is matched will be replaced,When deleting text, multiple lines of text can be matched,So these lines will be deleted
state	When you want to delete the corresponding text, you need to state The value of the parameter is set to absent，state The default value for is present
backrefs	No changes are made to the file when there are no matching rules for the content,The default value is no，Backward reference regexp Variable information
insertafter	With the help of insertafter Parameter can insert text after "specified line", insertafter The value of the parameter can be set to EOF Or regular expressions
insertbefore	With the help of insertbefore Parameter can insert text before the specified line, insertbefore The value of the parameter can be set to BOF Or regular expressions
backup	Do you want to back up the file before modifying it
create	If the file to be operated does not exist, do you want to create the corresponding file

replace module

Function: the replace module can replace the strings in the file according to the regular expression specified by us, and all matched strings in the file will be replaced

Common parameters

path	Specify the file to operate on
regexp	Specify a regular expression, and the string matching the regular expression in the file will be replaced.
replace	Specifies the string to eventually replace with
backup	Whether to back up files before modifying them, preferably set to yes

setup module

Function: the setup module is used to collect some basic information of the remote host

Common parameters

filter	Used for conditional filtering. If set, only the information matching the filter criteria is returned

debug module

Function: debugging module, used to output information during debugging

Common parameters

msg	   Debug output messages
var:	Pass the output of a task execution as a variable to debug modular, debug It will be printed out directly
verbosity: 	debug Level of (level 0 by default, all displayed)

mysql_user module

ansible server3 -m mysql_user -a "login_user=root name=wxh password=testpass priv='*.*:select' host='%' state=present"

MySQL Python needs to be installed on the remote host

Example:

Specify the node1 side to install MariaDB server

Specify the node1 side to start the service


Specify node1 end user authentication

You need to install MySQL Python on node1

After re authenticating the user, node1 can log in. The default mode is localhost

file module

Function: set file properties

Common parameters

path        Specify file name
state       Specify operation status
            touch            establish
            absent           delete
            directory        recursion
            link             Establish link
            hard
            
mode        Set permissions
owner       Set file user
group       Set file group
src         source file
dest        Target file
recurse=yes Recursive change

Example:

establish

ansible demo -m file -a 'path=/mnt/test.sh state=touch'

delete

ansible demo -m file -a 'path=/mnt/test.sh state=absent

Recursively change file permissions and properties

ansible demo -m file -a 'path=/mnt/westos state=directory mode=777 recurse=yes'