Introduction to Ansible
- It is an open source tool for configuration management and application-deployment
- Agent less server automation tool uses SSH to connect to other servers
- Installed on control node, with no agents to install on remote systems.
- We can run the tasks in parallel
- Supports multiple OS and cloud platforms
Key Concepts
- Control Node – A node on which ansible is installed, inventory is defined and playbooks are deployed
- Managed Node – Nodes which are connected to Control Node using ansible commands or playbooks
- Inventory – All managed nodes defined in a file as a groups
- Module – Component of ansible to perform common administrative tasks – E.g.: file, user, synchronize etc.
- Task
- Play Book
- Ansible Tower
Control Node Requirement
- Linux (Red Hat, Debian, CentOS) or macOS host with python 2 or 3 installed
- Windows is not supported as Control Node
Managed Node Requirement
- Python 2 or 3 should be installed
- If you have SELinux enabled on remote linux nodes, you will also want to install libselinux-python using the below command
yum install -y libselinux-python
Installing Ansible on Control Node
In Linux systems, by default Python 2 will be avaialble. If you want to install ansible on top of Python 2, we can directly use below yum install command.
yum install -y epel-release yum install -y ansible
Verify the ansible version using the below command
ansible --version
Ansible with Python 3
yum install -y python3 #To install python3 on red hat based systems
python3 will install python3-libs, python3-pip, python3-setuptools and libtirpc packages also.
To install ansible on python 3 use the below command
pip3 install ansible
Once ansible is installed, check the ansible version using below command.
ansible --version
Basic Ansible Commands
Here are some ansible ad-hoc commands:
Execute the hostnamectl command from ansible to get the hostname and related information.
ansible localhost -m shell -a "hostnamectl" ansible localhost -a "hostnamectl" #The default module is shell, we can use this
Using ansible ping module
ansible localhost -m ping
