# Playbook Example * In here I will examile a real use case example by creating and executing Ansible playbooks. I will install Nginx in all hosts and explore the different options for targeting OS variations with Ansible packages. * Use Ansible to install and configure project website, taking into account variances between the linux distributions of Nginx on both CentOS and Ubuntu. * Use Jinja2 templates to customise the website. Let's first create our ansible config file `ansible.cfg`: ``` [defaults] inventory = hosts host_key_checking = False ``` Next our group vars for centos and ubuntu hosts: `group_vars/centos`: ``` --- ansible_user: root ... ``` `group_vars/ubuntu`: ``` --- ansible_user: root ... ``` Next our host file `hosts`: ``` [control] ubuntu-c [centos] centos[1:3] [ubuntu] ubuntu[1:3] [linux:children] centos ubuntu ``` Next our playbook itself for installing EPEL on CentOS hosts: ``` --- # YAML documents begin with the document separator --- # The minus in YAML this indicates a list item. The playbook contains a list # of plays, with each play being a dictionary - # Hosts: where our play will run and options it will run with hosts: linux # Vars: variables that will apply to the play, on all target systems # Tasks: the list of tasks that will be executed within the play, this section # can also be used for pre and post tasks tasks: - name: Install EPEL yum: name: epel-release update_cache: yes state: latest when: ansible_distribution == 'CentOS' # Handlers: the list of handlers that are executed as a notify key from a task # Three dots indicate the end of a YAML document ... ``` Now we can execute the playbook: ``` $ ansible-playbook nginx_playbook.yaml PLAY [linux] ***************************************************************************************************************** TASK [Gathering Facts] ****************************************************************************************************************************** ok: [centos2] ok: [centos1] ok: [centos3] ok: [ubuntu1] ok: [ubuntu2] ok: [ubuntu3] TASK [Install EPEL] ****************************************************************************************************************************** skipping: [ubuntu1] skipping: [ubuntu2] skipping: [ubuntu3] changed: [centos1] changed: [centos3] changed: [centos2] PLAY RECAP ******************************************************************************************************************* centos1 : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 centos2 : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 centos3 : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 ubuntu1 : ok=1 changed=0 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0 ubuntu2 : ok=1 changed=0 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0 ubuntu3 : ok=1 changed=0 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0 ``` Now let's install Nginx in all hosts by slightly modifying the playbook `nginx_playbook.yaml`: ``` --- # YAML documents begin with the document separator --- # The minus in YAML this indicates a list item. The playbook contains a list # of plays, with each play being a dictionary - # Hosts: where our play will run and options it will run with hosts: linux # Vars: variables that will apply to the play, on all target systems # Tasks: the list of tasks that will be executed within the play, this section # can also be used for pre and post tasks tasks: - name: Install EPEL yum: name: epel-release update_cache: yes state: latest when: ansible_distribution == 'CentOS' - name: Install Nginx CentOS yum: name: nginx update_cache: yes state: latest when: ansible_distribution == 'CentOS' - name: Install Nginx Ubuntu apt: name: nginx update_cache: yes state: latest when: ansible_distribution == 'Ubuntu' # Handlers: the list of handlers that are executed as a notify key from a task # Three dots indicate the end of a YAML document ... ``` Once we execute it, the output should be something similar to below: ``` $ ansible-playbook nginx_playbook.yaml PLAY RECAP ******************************************************************************************************************* centos1 : ok=3 changed=2 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0 centos2 : ok=3 changed=2 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0 centos3 : ok=3 changed=2 unreachable=0 failed=0 skipped=1 rescued=0 ignored=0 ubuntu1 : ok=2 changed=1 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0 ubuntu2 : ok=2 changed=1 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0 ubuntu3 : ok=2 changed=1 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0 ``` or we can simply use Nginx module for that like below in `nginx_playbook.yaml`: ``` --- # YAML documents begin with the document separator --- # The minus in YAML this indicates a list item. The playbook contains a list # of plays, with each play being a dictionary - # Hosts: where our play will run and options it will run with hosts: linux # Vars: variables that will apply to the play, on all target systems # Tasks: the list of tasks that will be executed within the play, this section # can also be used for pre and post tasks tasks: - name: Install EPEL yum: name: epel-release update_cache: yes state: latest when: ansible_distribution == 'CentOS' - name: Install Nginx package: name: nginx state: latest # Handlers: the list of handlers that are executed as a notify key from a task # Three dots indicate the end of a YAML document ... ``` Next let's add a task to restart Nginx in our playbook: ``` --- # YAML documents begin with the document separator --- # The minus in YAML this indicates a list item. The playbook contains a list # of plays, with each play being a dictionary - # Hosts: where our play will run and options it will run with hosts: linux # Vars: variables that will apply to the play, on all target systems # Tasks: the list of tasks that will be executed within the play, this section # can also be used for pre and post tasks tasks: - name: Install EPEL yum: name: epel-release update_cache: yes state: latest when: ansible_distribution == 'CentOS' - name: Install Nginx package: name: nginx state: latest - name: Restart nginx service: name: nginx state: restarted # Handlers: the list of handlers that are executed as a notify key from a task # Three dots indicate the end of a YAML document ... ``` Now let's had a handler to add a http health check to make sure Nginx is running: ``` --- # YAML documents begin with the document separator --- # The minus in YAML this indicates a list item. The playbook contains a list # of plays, with each play being a dictionary - # Hosts: where our play will run and options it will run with hosts: linux # Vars: variables that will apply to the play, on all target systems # Tasks: the list of tasks that will be executed within the play, this section # can also be used for pre and post tasks tasks: - name: Install EPEL yum: name: epel-release update_cache: yes state: latest when: ansible_distribution == 'CentOS' - name: Install Nginx package: name: nginx state: latest - name: Restart nginx service: name: nginx state: restarted notify: Check HTTP Service # Handlers: the list of handlers that are executed as a notify key from a task handlers: - name: Check HTTP Service uri: url: http://{{ ansible_default_ipv4.address }} status_code: 200 # Three dots indicate the end of a YAML document ... ``` Next let's create group vars for HTML location for Nginx in different hosts, and create a jinja template for HTML. First let's nodify the playbook to deploy the HTML file inside Nginx: ``` --- # YAML documents begin with the document separator --- # The minus in YAML this indicates a list item. The playbook contains a list # of plays, with each play being a dictionary - # Hosts: where our play will run and options it will run with hosts: linux # Vars: variables that will apply to the play, on all target systems # Tasks: the list of tasks that will be executed within the play, this section # can also be used for pre and post tasks tasks: - name: Install EPEL yum: name: epel-release update_cache: yes state: latest when: ansible_distribution == 'CentOS' - name: Install Nginx package: name: nginx state: latest - name: Restart nginx service: name: nginx state: restarted notify: Check HTTP Service - name: Template index.html-base.j2 to index.html on target template: src: index.html-base.j2 dest: "{{ nginx_root_location }}/index.html" mode: 0644 # Handlers: the list of handlers that are executed as a notify key from a task handlers: - name: Check HTTP Service uri: url: http://{{ ansible_default_ipv4.address }} status_code: 200 # Three dots indicate the end of a YAML document ... ``` Next our group vars for centos and ubuntu hosts: `group_vars/centos`: ``` --- ansible_user: root nginx_root_location: /usr/share/nginx/html ... ``` `group_vars/ubuntu`: ``` --- ansible_user: root nginx_root_location: /var/www/html ... ``` Now let's add the `ansible_managed` variable in the `ansible.cfg`: ``` [defaults] inventory = hosts host_key_checking = False ansible_managed = Managed by Ansible - file:{file} - host:{host} - uid:{uid} ``` Now we can use the `ansible_managed` variable inside any of our templates. Now let's load out variables in the playbook. ``` --- # YAML documents begin with the document separator --- # The minus in YAML this indicates a list item. The playbook contains a list # of plays, with each play being a dictionary - # Hosts: where our play will run and options it will run with hosts: linux # Vars: variables that will apply to the play, on all target systems vars_files: - vars/logos.yaml # Tasks: the list of tasks that will be executed within the play, this section # can also be used for pre and post tasks tasks: - name: Install EPEL yum: name: epel-release update_cache: yes state: latest when: ansible_distribution == 'CentOS' - name: Install Nginx package: name: nginx state: latest - name: Restart nginx service: name: nginx state: restarted notify: Check HTTP Service - name: Template index.html-logos.j2 to index.html on target template: src: index.html-logos.j2 dest: "{{ nginx_root_location }}/index.html" mode: 0644 # Handlers: the list of handlers that are executed as a notify key from a task handlers: - name: Check HTTP Service uri: url: http://{{ ansible_default_ipv4.address }} status_code: 200 # Three dots indicate the end of a YAML document ... ``` Add unarchive task in the playbook to unarchive the code of our hidden game. ``` - name: Unarchive playbook stacker game unarchive: src: playbook_stacker.zip dest: "{{ nginx_root_location }}" mode: 0755 ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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