Ansible install and configure on ubuntu16.04LTS

Question

How to install and configure ansible on Ubuntu 16.04?

Answer 1

I don't use Ansible but I found this simple to follow tutorial from Digital Ocean, and these are the steps:

1. Installation:

   sudo apt-add-repository ppa:ansible/ansible
   sudo apt-get update
   sudo apt-get install ansible
   

2. Configuring Ansible Hosts:

   1. Edit sudo nano /etc/ansible/hosts:

      • Since the tutorial uses dummy hosts these would be added in a real situation:

        [group_name]
        alias ansible_ssh_host=your_server_ip
        

      • The group_name is an organizational tag that lets you refer to any servers listed under it with one word. The alias is just a name to refer to that server. So in our scenario, we are imagining that we have three servers we are going to control with Ansible. These servers are accessible from the Ansible server by typing:

        ssh root@your_server_ip
        

   2. We will assume that our servers' IP addresses are 192.0.2.1, 192.0.2.2, and 192.0.2.3. We will set this up so that we can refer to these individually as host1, host2, and host3, or as a group as servers:

      [servers]
      host1 ansible_ssh_host=192.0.2.1
      host2 ansible_ssh_host=192.0.2.2
      host3 ansible_ssh_host=192.0.2.3
      

3. With our current settings, if we tried to connect to any of these hosts with Ansible, the command would fail (assuming you are not operating as the root user). This is because your SSH key is embedded for the root user on the remote systems and Ansible will by default try to connect as your current user. A connection attempt will get this error:

   host1 | UNREACHABLE! => {
         "changed": false,
         "msg": "Failed to connect to the host via ssh.",
         "unreachable": true
   }
   

4. On the Ansible server, we're using a user called demo. Ansible will try to connect to each host with ssh demo@server. This will not work if the demo user is not on the remote system. We can create a file that tells all of the servers in the "servers" group to connect using the root user. To do this, we will create a directory in the Ansible configuration structure called group_vars. Within this folder, we can create YAML-formatted files for each group we want to configure:

    sudo mkdir /etc/ansible/group_vars
    sudo nano /etc/ansible/group_vars/servers
   

   • Add this in there:

     ---
     ansible_ssh_user: root
     

   • If you want to specify configuration details for every server, regardless of group association, you can put those details in a file at /etc/ansible/group_vars/all. Individual hosts can be configured by creating files under a directory at /etc/ansible/host_vars.

5. Using Simple Ansible Commands:

   ansible -m ping all
   
   # Output:
   host1 | SUCCESS => {
   "changed": false,
   "ping": "pong"
   }
   
   host3 | SUCCESS => {
   "changed": false,
   "ping": "pong"
   }
   
   host2 | SUCCESS => {
   "changed": false,
   "ping": "pong"
   }
   

   • The "all" means all hosts. We could just as easily specify a group:

     ansible -m ping servers
     

   • We could also specify an individual host:

     ansible -m ping host1
     

   • We can specify multiple hosts by separating them with colons:

     ansible -m ping host1:host2
     

   • The "shell" module lets us send a terminal command to the remote host and retrieve the results. For instance, to find out the memory usage on our host1 machine, we could use:

     ansible -m shell -a 'free -m' host1
     
     # Result:
     
     host1 | SUCCESS | rc=0 >>
      total       used       free     shared    buffers     cached
      Mem:          3954        227       3726          0         14         93
      -/+ buffers/cache:        119       3834
      Swap:            0          0          0
     

More information:

https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-ansible-on-ubuntu-16-04