This guide will teach you to install and configure Ansible control server on a Ubuntu/Centos/Redhat/fedora servers. Also, we will see how to configure hosts that have to be managed by Ansible server. I would strongly suggest using Vagrant for all Ansible test purposes.
Install and Configure Ansible
Choose any of the following three methods for installing Ansible based on your operating system.
1. Using Pip
If you have python pip in your system, use the following pip command.
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sudo pip install ansible |
2. Ubuntu
Execute the following commands to install ansible.
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sudo apt-add-repository -y ppa:ansible/ansible sudo apt-get update sudo apt-get install -y ansible |
3. Redhat/Centos/Fedora
Redhat/Centos 6
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sudo yum -y install ansible |
Redhat/Centos 7
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sudo yum -y install epel-release sudo yum -y install ansible |
Configuring hosts
Here I represent all the servers that have to be managed using Ansible as hosts. Ansible keeps track of the hosts using the inventory file ( A file with list of servers). It has the IP address/domain name of the hosts with username, password or key information to connect to the node.
All the default configurations are present in /etc/ansible/ansible.cfg file. Here you can change all the default paths if you want your own custom paths and configurations.
Now let’s disable host key checking by replacing the host_key_checking parameter to true so that Ansible won’t prompt for host key checking. This is not recommended for production deployments
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sed -i '/#host_key_checking = False/c\host_key_checking = True' /etc/ansible/ansible.cfg |
By default the inventory file named hosts is present in /etc/ansible/ directory. If you open the /etc/ansible/hosts you will find the sample host entries. Lets keeps this file as a backup and create our own hosts file.
Let’s create the backup of original hosts inventory file.
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sudo mv /etc/ansible/hosts /etc/ansible/hosts.original |
Create a new hosts file.
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sudo touch /etc/ansible/hosts |
Now we have an empty hosts inventory file. Let’s create it from scratch.
In every environment the servers are segregated as web group, DB group, app group etc.. we can have similar segregation in our inventory file using labels. It is a recommended way of managing servers. For instance, you might have dev, test and prod servers. In this case, you can group servers from different environments under different labels.
Create two new hosts, get its IP address, username, and password/key. We will use these new hosts for testing.
Now we have the Ansible control server and two hosts that need to be managed. My hosts IP addresses are 192.168.2.30 and 192.168.2.40 and I will be using it throughout the example. Replace it with your hosts IP address.
Define the hosts in /etc/ansible/hosts inventory file with dev, dev:vars and local label as shown below.
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[dev] 192.168.2.30 192.168.2.40 [dev:vars] ansible_user=vagrant ansible_ssh_pass=vargrant [local] 127.0.0.1 |
dev:vars parameters are applied to the servers under dev label. As we know that Ansible uses ssh for connecting to hosts. So we need to specify the username and password of those hosts. If all the servers have the same username and password, you can mention it in dev:vars label. If not you can specify it with the IP addresses separated by space as shown below.
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192.168.2.30 ansible_user=vagrant ansible_ssh_pass=vargrant |
the local label represents the Ansible server itself. So if you want to run a playbook on your ansible server, you can make use of the local label.
Test the Configuration Using an Ad-Hoc Command
Now we have every Configuration in place. Let’s test our configuration using the following command.
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ansible all -m ping |
You should get the following success message.
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vagrant@acs:/etc/ansible$ ansible all -m ping 192.168.2.30 | SUCCESS => { "changed": false, "ping": "pong" } 192.168.2.40 | SUCCESS => { "changed": false, "ping": "pong" } |
