Install and configure Ansible on Ubuntu

Install Ansible

Prepare two virtual machines for testing, the ip addresses are:

• ansible-server：192.168.100.124
• ansible-client：192.168.100.28

Execute the following command on ansible-server to install ansible:

root@ansible-server:~# apt update
root@ansible-server:~# apt install software-properties-common
root@ansible-server:~# apt-add-repository --yes --update ppa:ansible/ansible
root@ansible-server:~# apt install ansible -y

root@ansible-server:~# ansible --version
ansible 2.9.19
  config file = /etc/ansible/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/dist-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.17 (default, Feb 27 2021, 15:10:58) [GCC 7.5.0]

Ansible has been successfully installed on the ansible-server node, the version is 2.9.19.

Set up SSH Key Exchange

Ansible connects to the client via SSH, first produces a public key key on the server node, and then copies it to the client node.

root@ansible-server:~# ssh-keygen 
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:edjMAYYNV3V1nw4ggM+lMtl5bO55rSdIVJlfoeJ20GA root@ansible-server
The key's randomart image is:
+---[RSA 2048]----+
|      o==o.E+ .o+|
|     ..o.oo++...+|
|      = = oo.+...|
|     + * @..o.o  |
|      o S =o . . |
|         +. .    |
|        o o .    |
|         + o o   |
|          ..+    |
+----[SHA256]-----+
root@ansible-server:~# 
root@ansible-server:~# ls -l /root/.ssh/
total 20
-rw------- 1 root root 1675 3月  20 19:56 id_rsa
-rw-r--r-- 1 root root  401 3月  20 19:56 id_rsa.pub
-rw-r--r-- 1 root root  666 3月  20 18:02 known_hosts
-rw------- 1 root root 1679 3月  19 16:08 octavia_ssh_key
-rw-r--r-- 1 root root  391 3月  19 16:08 octavia_ssh_key.pub
root@ansible-server:~# 

Copy the public key key to the client node:

root@ansible-server:~# ssh-copy-id [email protected]
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
[email protected]'s password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh '[email protected]'"
and check to make sure that only the key(s) you wanted were added.

Configure Host

Edit /etc/ansible/hosts to add client information:

root@ansible-server:~# cat /etc/ansible/hosts 
# This is the default ansible 'hosts' file.
#
# It should live in /etc/ansible/hosts
#
#   - Comments begin with the '#' character
#   - Blank lines are ignored
#   - Groups of hosts are delimited by [header] elements
#   - You can enter hostnames or ip addresses
#   - A hostname/ip can be a member of multiple groups

# Ex 1: Ungrouped hosts, specify before any group headers.

## green.example.com
## blue.example.com
## 192.168.100.1
## 192.168.100.10

# Ex 2: A collection of hosts belonging to the 'webservers' group

## [webservers]
## alpha.example.org
## beta.example.org
## 192.168.1.100
## 192.168.1.110

# If you have multiple hosts following a pattern you can specify
# them like this:

## www[001:006].example.com

# Ex 3: A collection of database servers in the 'dbservers' group

## [dbservers]
## 
## db01.intranet.mydomain.net
## db02.intranet.mydomain.net
## 10.25.1.56
## 10.25.1.57

# Here's another example of host ranges, this time there are no
# leading 0s:

## db-[99:101]-node.example.com

[Client]
node1 ansible_ssh_host=192.168.100.28

Ansible test

As shown below, the test ping command is executed successfully:

root@ansible-server:~# ansible Client -m ping
node1 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    }, 
    "changed": false, 
    "ping": "pong"
}
root@ansible-server:~# 
root@ansible-server:~# 
root@ansible-server:~# 
root@ansible-server:~# ansible Client -m command -a 'hostname'
node1 | CHANGED | rc=0 >>
ansible-client