Ansible Setup and Running a Playbook

Published on June 11, 2021

Ansible is an automation tool, I've used it in a case where you have to run similar commands on multiple machines.

In this example I'll install an ftp server, nginx and also allow all connection on firewall.

sudo apt update
sudo apt install ansible

Setup SSH Keys on Host and Clients

To start running commands on multiple host machines we first have to setup ssh Keys in host machine and clients.

In my case:

10.2.4.49 (Host machine/localhost)
10.2.4.50 (Client)
10.2.4.51 (Client)

ssh-keygen
# Fill the options, just remember what name you save your key with 
# Enter file in which to save the key: /root/.ssh/ansible_host

# Copy ssh public key wherever you want to run your commands
ssh-copy-id -i /root/.ssh/ansible_host.pub username@localhost
ssh-copy-id -i /root/.ssh/ansible_host.pub username@10.2.4.50
ssh-copy-id -i /root/.ssh/ansible_host.pub username@10.2.4.51


# login to your machines and copy the keys in root, 
# for some reason I'm not able to copy them directly into root
cp /home/username/.ssh/authorized_keys /root/.ssh/

Configure Ansible

Once ssh keys are done, add IPs in hosts and then edit your .cfg as follows

cd /etc/ansible/

vim hosts
# Edit servers and add your IPs and exit

[servers]
server1 ansible_host=localhost
server2 ansible_host=10.2.4.50
server3 ansible_host=10.2.4.51


# Edit ansible configurations and add inventory & ssh private key path
vim ansible.cfg

[defaults]
inventory = hosts
private_key_file = /root/.ssh/ansible_host

Running Ansible

To check ansible is working run ping

ansible all -m ping


# Output
server1 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
server2 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
server3 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

Create an Ansible playbook

Create a yaml file, this is a playbook which we'll run via ansible-playbook command. Ansible playbook contains multiple Plays which consist of metadata and a sequence of task and handler definitions, and roles.

# Create a yaml 
vim ftp_http_installer.yml

# Add the following lines
---

- name: Configure ftp server
  hosts: all
  remote_user: ta
  become: true
  tasks:
  - name: Installs vsftpd server
    apt:
      name: vsftpd
      state: latest
  - name: starts vsftpdf service
    service:
      name: vsftpd
      state: started
      enabled: true
- name: Configure http server
  hosts: all
  remote_user: ta
  become: true
  tasks:
  - name: Allow everything in ufw
    ufw:
      state: enabled
      policy: allow
  - name: Installs httpd server
    apt:
      name: nginx
      state: latest
      update_cache: yes
  - name: starts httpd service
    service:
      name: nginx
      state: started
      enabled: true
  - name: Create index.html
    copy:
      dest: /var/www/html/index.html
      content: "Created by Ansible"

Running the Playbook

# Check syntax of yaml with ansible-playbook 
ansible-playbook ftp_http_installer.yml --syntax-check

# Before Running the playbook check it first with ---check/-C
# which means: don't make any changes; instead, try to predict changes
# And finally -K means it will ask for password to run as root
ansible-playbook -C ftp_http_server.yml -K

# If everything goes well and nothing fails
ansible-playbook ftp_http_server.yml -K

Final Output will look something like this

# Final Output
BECOME password:

PLAY [Configure ftp server] **************************************************************************

TASK [Gathering Facts] *******************************************************************************
ok: [server1]
ok: [server2]

TASK [Installs vsftpd server] ************************************************************************
changed: [server2]
changed: [server1]

TASK [starts vsftpdf service] ************************************************************************
ok: [server2]
ok: [server1]

PLAY [Configure http server] *************************************************************************

TASK [Gathering Facts] *******************************************************************************
ok: [server1]
ok: [server2]

TASK [Allow everything in ufw] ***********************************************************************
changed: [server2]
changed: [server1]

TASK [Installs httpd server] *************************************************************************
changed: [server2]
changed: [server1]

TASK [starts httpd service] **************************************************************************
ok: [server1]
ok: [server2]

TASK [Create index.html] *****************************************************************************
changed: [server1]
changed: [server2]

PLAY RECAP *******************************************************************************************
server1                    : ok=8    changed=4    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
server2                    : ok=8    changed=4    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Testing our FTP Server & Http Server

curl 10.2.4.50

# Output
Created by Ansible


ftp -p 10.2.4.50

# Output
Connected to 10.2.4.50.
220 (vsFTPd 3.0.3)
Name (10.2.4.50:server): xuser
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> ls
227 Entering Passive Mode (10,2,4,64,166,217).
150 Here comes the directory listing.
drwxr-xr-x    5 1000     1000         4096 May 31 10:02 Desktop
drwxr-xr-x    3 1000     1000         4096 May 24 12:49 Documents
drwxr-xr-x    2 1000     1000         4096 May 24 12:08 Downloads
drwxr-xr-x    2 1000     1000         4096 May 24 12:08 Music
drwxr-xr-x    2 1000     1000         4096 May 24 12:08 Pictures
drwxr-xr-x    2 1000     1000         4096 May 24 12:08 Public
drwxr-xr-x    2 1000     1000         4096 May 24 12:08 Templates
drwxr-xr-x    3 1000     1000         4096 May 24 12:49 Videos
drwxr-xr-x    4 1000     1000         4096 May 25 12:09 snap
226 Directory send OK.

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Abid Zaidi

Abid Zaidi

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