RHCE EX294V84 Preparation

[cvb97]

Hello, I have set up a lab for RHCE EX294V84 exam so that I can get lots of practice hours. I have installed ansible-core, which automatically installs python3, what other packages do I need to fully simulate an exam environment.  

[cvb97]

Hi I have goine through rh294-84,rh294-9.0,rh134-90 and rh124-9.0 just to make sure I did not miss something, in all these coarses no 1 mention on how to get PHP and Balancers working with roles.

Does RH not teach the how to get load balancers (haproxy) with php roles to students ??. and whew can I get these 2 roles to work on CentoOS 8.4

[Punyabrata]

Hello , I am also preparing for RHCE , I think you can not get the roles downloaded in your home environment , so you can just copy the setup from Red Hat Labs - I mean just take screen shots and reproduce manually in your setup. In the real exam - we will get URLs to download the roles from a location , which is not available in home setup. 

[cvb97]

Hi, getting the roles isn't the problem, I'm trying to learn, practice on how to setup balancers and php roles from 3 machines (VMs), nowhere in the labs does it show,teach or even mention how to set up these roles once you have downloaded them, you can get similar roles from galaxy. 

I need to understand how to setup them up.

Thanks.

[Ricardo · Accepted solution]

More important than using the roles, is to understand how the balancers work. The roles are only tools to help you optimise and automate manual tasks. Understanding what's behind them will help you understand what's in the role and how to use it.

A role is an efficient way to generalize tasks and re-use them, but you should understand the mechanics of the task you're trying to accomplish, because this will help you write better playbooks/roles and solve any other situation you may find during the execution.

[cvb97]

Thank Ricardo, and that the point im trying to make, where do i get documentation, training, advice on how the balnacers machanics work.

[JustinS1982]

Generally you would look at the roles README.md and/or example playbook that would tell you the backend methods and server configuration variables needed to complete the request. For example, geerlingguy.haproxy role.... if you look at the README.md for that role, it will tell you all you need to know.

I also happen to know why you are asking this question as I have ended here for the same reason. In my example above, it is very easy to accomplish this as the role is well detailed. However, when those details are not present in a role then becomes frustrating because then you have no idea what the variable naming convention is for said role to use in your included playbook variables.

For roles lacking any "must-know" variable information in a README.md, example role playbook, in any of the role directory files (unless by some wild guess you know what variables its looking to translate) then it is a poorly constructed role in the sense the role is lacking adequate documentation to use it. That is the entire point of a role... to simplify a process.


You could try to analyze what the role is doing via its /tasks/main.yml or /handlers/main.yml, its /templates files or it's /vars details.... but again, its time consuming cobbling it together and that makes for a bad role. Good roles have proper documenation in their README.md and/or example playbooks.

[KentPerrier]

I, too, found some of the provided roles to not be documented at all, README.md was the default that is generated from init-ing a new role. I found it necessary to appeal to the ultimate documentation, the code in the role itself, looking at the tasks, default variables, etc. to see what it expected and what I needed to provide or override to meet the requirements of the objective.