Ansible Installation and Basic Usage Guide

Before installing Ansible, prepare a small lab consisting of two worker nodes (node1 and node2) and a control server (ansible.server.com). The table below lists each host’s role, hostname, OS release, and IP address.

Role

Hostname

SystemRelease

IP address

node1

node1.server.com

Rhel-6.5_x86_64

192.168.1.63

node2

node2.server.com

Rhel-6.5_x86_64

192.168.1.64

server

ansible.server.com

CentOS-6.5_x86_64

192.168.1.20

1. Preparation

Disable the firewall, change the hostname, and update the /etc/sysconfig/network file on each node. Then log out and log back in (or reboot) to apply the changes. Finally, add host entries to /etc/hosts so the nodes can resolve each other.

#关闭防火墙
service iptables stop
chkconfig iptables off
#更改主机名
hostname node1.server.com
vim /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=node1.server.com
logout  # 注销 重新登录 或者是 reboot 重启
#添加hosts解析
tail -3 /etc/hosts
192.168.1.63 node1.server.com        #node1
192.168.1.64 node2.server.com        #node2
192.168.1.20 ansible.server.com      #ansible

2. Install Ansible

rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
yum install ansible -y       #安装 ansible

After installation, the main configuration file is /etc/ansible/ansible.cfg and the default inventory file is /etc/ansible/hosts. The following command lists all files installed by the Ansible package.

rpm -ql ansible | more
/etc/ansible
/etc/ansible/ansible.cfg     # main config file
/etc/ansible/hosts           # inventory file
/etc/ansible/roles
/usr/bin/ansible
/usr/bin/ansible-console
/usr/bin/ansible-doc
/usr/bin/ansible-galaxy
/usr/bin/ansible-playbook
/usr/bin/ansible-pull
/usr/bin/ansible-vault

3. Configure Inventory and SSH Keys

Add the two worker nodes to the inventory under a group called webserver:

tail -3 /etc/ansible/hosts
[webserver]
node1.server.com
node2.server.com

Generate an SSH key pair on the control server and copy the public key to each node to enable password‑less authentication.

ssh-keygen
ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected]
ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected]

4. Common Ansible Commands

Check the current date on all nodes (the command module is the default, so it can be omitted):

ansible all -a date
ansible all -m command -a date

Verify connectivity using the built‑in ping module: ansible all -m ping # 内建的 ping 模块 Run arbitrary shell commands on every node, for example to echo a message, display disk usage, or show the Ethernet interface configuration:

ansible all -a "/bin/echo hello,world"    # 输出信息
ansible all -a "/bin/df -h"                # 输出挂载信息
ansible all -a "/sbin/ip addr show dev eth0" # 查看 eth0 网卡信息

These steps provide a basic, reproducible Ansible environment for managing Linux hosts.

Thank you for reading; feel free to leave a comment or share this guide with others.