{"id":1715,"date":"2019-12-24T11:35:00","date_gmt":"2019-12-24T06:05:00","guid":{"rendered":"https:\/\/opstree.com\/blog\/\/?p=1715"},"modified":"2020-02-24T17:02:02","modified_gmt":"2020-02-24T11:32:02","slug":"how-to-test-ansible-playbook-role-using-molecule-with-docker","status":"publish","type":"post","link":"https:\/\/opstree.com\/blog\/2019\/12\/24\/how-to-test-ansible-playbook-role-using-molecule-with-docker\/","title":{"rendered":"How to test Ansible playbook\/role using Molecules with Docker"},"content":{"rendered":"\r\n
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Why Molecule?<\/h2>\r\n\r\n\r\n\r\n

Have you ever faced issue that your Ansible code gets executed successfully but something went wrong like, service is not started, the configuration is not getting changed, etc?<\/p>\r\n

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There is another issue which you might have faced, that your code is running successfully on Redhat 6 but not running successfully on Redhat 7, to make your code smart enough to run on every Linux flavour, in order to achieve this, molecule came into the picture. Let’s start some brainstorm in Molecule.<\/p>\r\n\r\n\r\n\r\n

Molecule has capability to execute YML linter and custom test cases which you have written for your Ansible code. We will explain the linter and test cases below<\/p>\r\n\r\n\r\n\r\n

Why code testing is required?<\/h2>\r\n\r\n\r\n\r\n

Sometimes during the playbook execution, although it executes playbook fine but it does not give us the desired result so in order to check this we should use code testing in Ansible.<\/p>\r\n\r\n\r\n\r\n

In general, code testing helps developer to find bugs in code\/application and make sure the same bugs don’t cause the application to break. it also helps us to deliver application\/software as per standard of code. code testing helps us to increase code stability.<\/p>\r\n\r\n\r\n\r\n

Introduction :<\/h2>\r\n\r\n\r\n\r\n

This whole idea is all about to use Molecule (A testing tool) you can test your Ansible code whether it’s functioning correctly on all Linux flavour including all its functionalities or not.<\/p>\r\n\r\n\r\n\r\n

Molecule is a code linter program that analyses your source code for potential errors. It can detect errors such as syntax errors; structural problems like the use of undefined variables, etc.<\/p>\r\n\r\n\r\n\r\n

The molecule has capabilities to create a VM\/Container environment automatically and on top, it will execute your ansible code to verify all its functionalities.<\/p>\r\n\r\n\r\n\r\n

Molecule Can also check syntax, idempotency, code quality, etc<\/p>\r\n\r\n\r\n\r\n

Molecule only support Ansible 2.2 or latest version<\/p>\r\n\r\n\r\n\r\n

NOTE: To run ansible role with the molecule in different OS flavour we can use the cloud, vagrant, containerization (Docker)
Here we will use Docker\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026<\/p>\r\n\r\n\r\n\r\n

Let’s Start\u2026\u2026\u2026\u2026\u2026<\/p>\r\n\r\n\r\n\r\n

How Molecule works:<\/h2>\r\n\r\n\r\n\r\n

“When we setup molecule a directory with name “molecule” creates inside ansible role directory then it reads it’s main configuration file “molecule.yml” inside molecule directory. Molecule then creates platform (containes\/Instances\/Servers) in your local machine once completed it executes Ansible playbook\/role inside newly created platform after successful execution, it executes test cases. Finally Molecule destroy all newly created platform”<\/p>\r\n\r\n\r\n\r\n

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Installation of Molecule:<\/h2>\r\n\r\n\r\n\r\n

Installation of the molecule is quite simple.<\/p>\r\n\r\n\r\n\r\n

$ sudo apt-get update\r\n$ sudo apt-get install -y python-pip libssl-dev\r\n$ pip install molecule [ Install Molecule ]\r\n$ pip install --upgrade --user setuptools [ do not run in case of VM ]<\/pre>\r\n\r\n\r\n\r\n
That’s it\u2026\u2026\u2026\u2026<\/p>\r\n\r\n\r\n\r\n
Now it’s time to setup Ansible role with the molecule. We have two option to integrate Ansible with molecule:<\/p>\r\n\r\n\r\n\r\n
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  1. With New Ansible role<\/li>\r\n
  2. with existing Ansible role<\/li>\r\n<\/ol>\r\n\r\n\r\n\r\n
    1. Setup new ansible role with molecule:<\/h2>\r\n\r\n\r\n\r\n
    $ molecule init role --role-name ansible-role-nginx --driver-name docker<\/pre>\r\n\r\n\r\n\r\n
    When we run above command, a molecule directory will be created inside the ansible role directory<\/p>\r\n\r\n\r\n\r\n
    2. Setup the existing ansible role with molecule:<\/h2>\r\n\r\n\r\n\r\n
    Goto inside ansible role and run below command.<\/p>\r\n\r\n\r\n\r\n
    $ molecule init scenario --driver-name docker<\/pre>\r\n\r\n\r\n\r\n
    When we run above command, a molecule directory will be created inside the ansible role directory<\/p>\r\n\r\n\r\n\r\n
    NOTE: Molecule internally uses ansible-galaxy init command to create a role<\/p>\r\n\r\n\r\n\r\n
    Below is the main configuration file of the molecule:<\/p>\r\n\r\n\r\n\r\n