[root@master ~]# vi hosts.py
[root@master ~]# cat hosts.py
#!/usr/bin/env python3
import argparse
import sys
import json
def lists():
  r = {}
  h = [ '192.168.242.1' + str(i) for i in range(0,2) ]
  hosts = {'host': h}
  r['docker'] = hosts
  return json.dumps(r,indent=3)

def hosts(name):
  r = {'ansible_ssh_pass': '123'}
  cpis=dict(r.items())
  return json.dumps(cpis)

if __name__ == '__main__':
  parser = argparse.ArgumentParser()
  parser.add_argument('-l', '--list' , help='hosts list' , action='store_true')
  parser.add_argument('-H', '--host', help='hosts vars')
  args = vars(parser.parse_args())
  if args['list']:
    print(lists())
  elif args['host']:
    print(hosts(args['host']))
  else:
    parser.print_help()

Test script

[root@master ~]# chmod +x hosts.py
[root@master ~]# ./hosts.py -l
{
   "docker": {
      "host": [
         "192.168.242.10",
         "192.168.242.11",
         "192.168.242.12"
      ]
   }
}

[root@master ~]# ./hosts.py -H 192.168.242.12
{"ansible_ssh_pass": "123"}

[root@master ~]# tree /etc/ansible/
/etc/ansible/
├── ansible.cfg    #ansible configuration file
├── hosts          #Resource manifest file
└── roles

1 directory, 2 files

Host connectivity test

#Modify the configuration of hosts and groups
[root@master ~]# cat >> /etc/ansible/hosts << EOF
> [webservers]
> node[1:2]
> EOF

#Test a host
[root@master ~]# ansible node1 -m ping
node1 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python"
    },
    "changed": false,
    "ping": "pong"
}

#Test a set of hosts
[root@master ~]# ansible webservers -m ping
node1 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python"
    },
    "changed": false,
    "ping": "pong"
}
node2 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python"
    },
    "changed": false,
    "ping": "pong"
}

Batch execute command

#Use ansible to output "hello ansible" on the remote machine“

#Using shell modules
[root@master ~]# ansible webservers -m shell -a '/bin/echo hello ansible!' -o
node2 | CHANGED | rc=0 | (stdout) hello ansible!
node1 | CHANGED | rc=0 | (stdout) hello ansible!


#Using the command module
[root@master ~]# ansible webservers -a '/bin/echo hello ansible!' -o
node1 | CHANGED | rc=0 | (stdout) hello ansible!
node2 | CHANGED | rc=0 | (stdout) hello ansible!

#Using raw module
[root@master ~]# ansible webservers -m raw -a '/bin/echo hello ansible!'
node1 | CHANGED | rc=0 >>
hello ansible!
Shared connection to node1 closed.

node2 | CHANGED | rc=0 >>
hello ansible!
Shared connection to node2 closed.

Get help

Ansible doc: used to view module information

//Parameter - 1 lists the available modules

[root@master ~]# ansible-doc -l
fortios_router_community_list                                 Configure community lists in Fortinet's FortiOS and FortiGate
azure_rm_devtestlab_info                                      Get Azure DevTest Lab facts
ecs_taskdefinition                                            register a task definition in ecs
avi_alertscriptconfig                                         Module for setup of AlertScriptConfig Avi RESTful Object
tower_receive                                                 Receive assets from Ansible Tower
netapp_e_iscsi_target                                         NetApp E-Series manage iSCSI target configuration
azure_rm_acs                                                  Manage an Azure Container Service(ACS) instance
fortios_log_syslogd2_filter                                   Filters for remote system server in Fortinet's FortiOS and FortiGate

//-s) list the actions supported by a module

[root@master ~]# ansible-doc -s shell
- name: Execute shell commands on targets
  shell:
      chdir:                 # Change into this directory before running the command.
      cmd:                   # The command to run followed by optional arguments.
      creates:               # A filename, when it already exists, this step will *not*
                               be run.
      executable:            # Change the shell used to execute the command. This
                               expects an absolute path
                               to the executable.
      free_form:             # The shell module takes a free form command to run, as a
                               string. There is no actual
                               parameter named 'free
                               form'. See the examples on
                               how to use this module.
      removes:               # A filename, when it does not exist, this step will *not*
                               be run.
      stdin:                 # Set the stdin of the command directly to the specified
                               value.
      stdin_add_newline:     # Whether to append a newline to stdin data.
      warn:                  # Whether to enable task warnings.