Workshop Exercise - Workflows

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Table Contents

Objective

The basic idea of a workflow is to link multiple Job Templates together. They may or may not share inventory, Playbooks or even permissions. The links can be conditional:

And the workflows are not even limited to Job Templates, but can also include project or inventory updates.

This enables new applications for Ansible Tower: different Job Templates can build upon each other. E.g. the networking team creates playbooks with their own content, in their own Git repository and even targeting their own inventory, while the operations team also has their own repos, playbooks and inventory.

In this lab you’ll learn how to setup a workflow.

Guide

Lab Scenario

You have two departments in your organization:

When there is a new Node.js server to deploy, two things need to happen:

Web Operations Team

Web Developers Team


To make things somewhat easier for you, everything needed already exists in a Github repository: Playbooks, JSP-files etc. You just need to glue it together.

Note

In this example we use two different branches of the same repository for the content of the separate teams. In reality the structure of your SCM repositories depends on a lot of factors and could be different.

Set up Projects

First you have to set up the Git repo as a Project like you normally would.

Warning

If you are still logged in as user wweb, log out of and log in as user admin again.**

Create the project for the web operations team. In the Projects view click the green plus button and fill it in as follows:

Parameter Value
NAME Webops Git Repo
ORGANIZATION Default
SCM TYPE Git
SCM URL https://github.com/ansible/workshop-examples.git
SCM BRANCH/TAG/COMMIT webops
SCM UPDATE OPTIONS
  • ✓ CLEAN
  • ✓ DELETE ON UPDATE
  • ✓ UPDATE REVISION ON LAUNCH

Click SAVE


Create the project for the web developers team. In the Projects view click the green plus button and fill it in as follows:

Parameter Value
NAME Webdev Git Repo
ORGANIZATION Default
SCM TYPE Git
SCM URL https://github.com/ansible/workshop-examples.git
SCM BRANCH/TAG/COMMIT webdev
SCM UPDATE OPTIONS
  • ✓ CLEAN
  • ✓ DELETE ON UPDATE
  • ✓ UPDATE REVISION ON LAUNCH

Click SAVE

Set up Job Templates

Now you have to create two Job Templates like you would for “normal” Jobs.

Go to the Templates view, click the green plus button and choose Job Template:

Parameter Value
NAME Web App Deploy
JOB TYPE Run
INVENTORY Workshop Inventory
PROJECT Webops Git Repo
PLAYBOOK rhel/webops/web_infrastructure.yml
CREDENTIAL Workshop Credentials
LIMIT web
OPTIONS ✓ ENABLE PRIVILEGE ESCALATION

Click SAVE


Go to the Templates view, click the green plus button and choose Job Template:

Parameter Value
NAME Node.js Deploy
JOB TYPE Run
INVENTORY Workshop Inventory
PROJECT Webdev Git Repo
PLAYBOOK rhel/webdev/install_node_app.yml
CREDENTIAL Workshop Credentials
LIMIT web
OPTIONS ✓ ENABLE PRIVILEGE ESCALATION

Click SAVE

Tip

If you want to know what the Ansible Playbooks look like, check out the Github URL and switch to the appropriate branches.

Set up the Workflow

Set up the workflow. Workflows are configured in the Templates view, you might have noticed you can choose between Job Template and Workflow Template when adding a template.

workflow add

Go to the Templates view and click the green plus button. This time choose Workflow Template

NAME Deploy Webapp Server
ORGANIZATION Default

Click SAVE

After saving the template the Workflow Visualizer opens to allow you to build a workflow. You can later open the Workflow Visualizer again by using the button on the template details page.

Tip

Using the red “x” allows you to remove the node, the green plus lets you add the next node and the chain-symbol links to another node.

Tip

The type allows for more complex workflows. You could lay out different execution paths for successful and for failed playbook runs.

Tip

The Workflow Visualizer has options for setting up more advanced workflows, please refer to the documentation.

Launch Workflow

Your workflow is ready to go, launch it.

Click the blue LAUNCH button directly or go to the Templates view and launch the Deploy Webapp Server workflow by clicking the rocket icon.

launch

Note how the workflow run is shown in the job view. In contrast to a normal job template job execution this time there is no playbook output on the right, but a visual representation of the different workflow steps. If you want to look at the actual playbooks behind that, click DETAILS in each step. If you want to get back from a details view to the corresponding workflow, click the w-button in the JOB TEMPLATE line in the DETAILS part on the left side of the job overview.

jobs view of workflow

After the job was finished, check if everything worked fine: log into node1, node2 or node3 from your control host and run:

#> curl http://localhost/nodejs

You can also execute curl on the control host, pointing it towards the nodes and query the nodejs path, it should also show the simple nodejs application.


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