Red Hat Enterprise Linux Automation with Ansible

Procedure 7.2. Instructions

1. Change to the /home/student/role-create working directory.

   [student@workstation ~]$ cd ~/role-create
   [student@workstation role-create]$

2. Create the directory structure for a role called myvhost. The role includes fixed files, templates, tasks, and handlers.

   [student@workstation role-create]$ mkdir -v roles; cd roles
   mkdir: created directory 'roles'
   [student@workstation roles]$ ansible-galaxy init myvhost
   - myvhost was created successfully
   [student@workstation roles]$ rm -rvf myvhost/{defaults,vars,tests}
   removed 'myvhost/defaults/main.yml'
   removed directory: 'myvhost/defaults'
   removed 'myvhost/vars/main.yml'
   removed directory: 'myvhost/vars'
   removed 'myvhost/tests/inventory'
   removed 'myvhost/tests/test.yml'
   removed directory: 'myvhost/tests'
   [student@workstation roles]$ cd ..
   [student@workstation role-create]$

3. Edit the main.yml file in the tasks subdirectory of the role. The role should perform the following tasks:

   • The httpd package is installed

   • The httpd service is started and enabled

   • The web server configuration file is installed, using a template provided by the role

   1. Edit the roles/myvhost/tasks/main.yml file. Include code to use the yum module to install the httpd package. The file contents should look like the following:

      ---
      # tasks file for myvhost
      
      - name: Ensure httpd is installed
        yum:
          name: httpd
          state: latest

   2. Add additional code to the roles/myvhost/tasks/main.yml file to use the service module to start and enable the httpd service.

      - name: Ensure httpd is started and enabled
        service:
          name: httpd
          state: started
          enabled: true

   3. Add another stanza to use the template module to create /etc/httpd/conf.d/vhost.conf on the managed host. It should call a handler to restart the httpd daemon when this file is updated.

      - name: vhost file is installed
        template:
          src: vhost.conf.j2
          dest: /etc/httpd/conf.d/vhost.conf
          owner: root
          group: root
          mode: 0644
        notify:
          - restart httpd

   4. Save your changes and exit the roles/myvhost/tasks/main.yml file.

4. Create the handler for restarting the httpd service. Edit the roles/myvhost/handlers/main.yml file and include code to use the service module, then save and exit. The file contents should look like the following:

   ---
   # handlers file for myvhost
   
   - name: restart httpd
     service:
       name: httpd
       state: restarted

5. Move the vhost.conf.j2 template from the project directory to the role's templates subdirectory.

   [student@workstation role-create]$ mv -v vhost.conf.j2 roles/myvhost/templates/
   renamed 'vhost.conf.j2' -> 'roles/myvhost/templates/vhost.conf.j2'

6. Create the HTML content to be served by the web server.

   1. Create the files/html/ directory to store the content in.

      [student@workstation role-create]$ mkdir -pv files/html
      mkdir: created directory 'files/html'

   2. Create an index.html file below that directory with the contents: simple index.

      [student@workstation role-create]$ echo \
      > 'simple index' > files/html/index.html

7. Test the myvhost role to make sure it works properly.

   1. Write a playbook that uses the role, called use-vhost-role.yml. Include a task to copy the HTML content from files/html/. Use the copy module and include a trailing slash after the source directory name. It should have the following content:

      ---
      - name: Use myvhost role playbook
        hosts: webservers
        pre_tasks:
          - name: pre_tasks message
            debug:
              msg: 'Ensure web server configuration.'
      
        roles:
          - myvhost
      
        post_tasks:
          - name: HTML content is installed
            copy:
              src: files/html/
              dest: "/var/www/vhosts/{{ ansible_hostname }}"
      
          - name: post_tasks message
            debug:
              msg: 'Web server is configured.'

      Note

      The trailing slash causes the source directory and all of its contents to be copied to the managed host.

   2. Before running the playbook, verify that its syntax is correct by running ansible-playbook with the --syntax-check. If it reports any errors, correct them before moving to the next step. You should see output similar to the following:

      [student@workstation role-create]$ ansible-playbook use-vhost-role.yml \
      > --syntax-check
      
      playbook: use-vhost-role.yml

   3. Run the playbook. Review the output to confirm that Ansible performed the actions on the web server, servera.

      [student@workstation role-create]$ ansible-playbook use-vhost-role.yml
      
      PLAY [Use myvhost role playbook] *********************************************
      
      TASK [Gathering Facts] *******************************************************
      ok: [servera.lab.example.com]
      
      TASK [pre_tasks message] *****************************************************
      ok: [servera.lab.example.com] => {
          "msg": "Ensure web server configuration."
      }
      
      TASK [myvhost : Ensure httpd is installed] ***********************************
      changed: [servera.lab.example.com]
      
      TASK [myvhost : Ensure httpd is started and enabled] *************************
      changed: [servera.lab.example.com]
      
      TASK [myvhost : vhost file is installed] *************************************
      changed: [servera.lab.example.com]
      
      RUNNING HANDLER [myvhost : restart httpd] ************************************
      changed: [servera.lab.example.com]
      
      TASK [HTML content is installed] ***********************************
      changed: [servera.lab.example.com]
      
      TASK [post_tasks message] ****************************************************
      ok: [servera.lab.example.com] => {
          "msg": "Web server is configured."
      }
      
      PLAY RECAP *******************************************************************
      servera.lab.example.com    : ok=8    changed=5    unreachable=0    failed=0

   4. Run ad hoc commands to confirm that the role worked. The httpd package should be installed and the httpd service should be running.

      [student@workstation role-create]$ ansible webservers -a \
      > 'systemctl is-active httpd'
      servera.lab.example.com | CHANGED | rc=0 >>
      active
      
      [student@workstation role-create]$ ansible webservers -a \
      > 'systemctl is-enabled httpd'
      servera.lab.example.com | CHANGED | rc=0 >>
      enabled

   5. The Apache configuration should be installed with template variables expanded.

      [student@workstation role-create]$ ansible webservers -a \
      > 'cat /etc/httpd/conf.d/vhost.conf'
      servera.lab.example.com | CHANGED | rc=0 >>
      # Ansible managed:
      
      <VirtualHost *:80>
          ServerAdmin webmaster@servera.lab.example.com
          ServerName servera.lab.example.com
          ErrorLog logs/servera-error.log
          CustomLog logs/servera-common.log common
          DocumentRoot /var/www/vhosts/servera/
      
          <Directory /var/www/vhosts/servera/>
              Options +Indexes +FollowSymlinks +Includes
              Order allow,deny
              Allow from all
          </Directory>
      </VirtualHost>

   6. The HTML content should be found in a directory called /var/www/vhosts/servera. The index.html file should contain the string "simple index".

      [student@workstation role-create]$ ansible webservers -a \
      > 'cat /var/www/vhosts/servera/index.html'
      servera.lab.example.com | CHANGED | rc=0 >>
      simple index

   7. Use the uri module in an ad hoc command to check that the web content is available locally. Set the return_content parameter to true to have the content of the server's response added to the output. The server content should be the string simple index\n.

      [student@workstation role-create]$ ansible webservers -m uri \
      > -a 'url=http://localhost return_content=true'
      servera.lab.example.com | SUCCESS => {
          "accept_ranges": "bytes",
          "changed": false,
          "connection": "close",
          "content": "simple index\n",
      ...output omitted...
          "status": 200,
          "url": "http://localhost"
      }

   8. Confirm that the web server content is available to remote clients.

      [student@workstation role-create]$ curl http://servera.lab.example.com
      simple index