Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/r0x0d/redhat-interview

RHEL Migrations Interview
https://github.com/r0x0d/redhat-interview

Last synced: about 2 months ago
JSON representation

RHEL Migrations Interview

Awesome Lists containing this project

README 

        
# Introduction



This is a simple code implementation for the Software Engineering - RHEL Migrations interview, it's intended to run on any rpm-based operating system, such as: Fedora, CentOS, RHEL, etc...



This code aims to get the current kernel versions installed on a running machine, it uses the `dnf` API to get metadata information about those packages and print them in a simple format to the stdout. 



# Getting the kernel version on your system



To run the script and check the installed versions, you can simple run the following command in any terminal you like.



```bash

$ python redhat_interview/main.py

```



Or, if you prefer, you could use `make` to run the same exactly command.



```bash

$ make # Same as the command above

```



For default, we use `python` as the executable choice when running the `make` command, and it depends on wether you have `python2` or `python3` linked as `python` in your current system. 



Also, there is a recording showing the output of the above command being ran in my own machine.

[![asciicast](https://asciinema.org/a/3TBTGdzXFnPwC8zpTChD1HHeo.svg)](https://asciinema.org/a/3TBTGdzXFnPwC8zpTChD1HHeo)



As a counter example, this is a record of the above command being ran with python2 (I don't have the `python2-dnf` pacakge installed on my machine) and failling immediatly as it cannot recognize the `dnf` module being imported.



[![asciicast](https://asciinema.org/a/xvAQXgm6f47JOyW69avXQX9ri.svg)](https://asciinema.org/a/xvAQXgm6f47JOyW69avXQX9ri) 



# Common problems found during the development



While I was trying to implement a test case using `virtualenv` and `pytest` I found out that the newly generated `virtualenv` couldn't see the outside libraries in my machine (thus, the `python3-dnf` wasn't loaded for the `dnf` module use). I don't known if this is a common case or a misconfiguration by my side, but the workaround I got was making a `Dockerfile` for `CentOS` and `Fedora` to run the tests on. Those images are intended to run inside the `Github Actions` pipeline, but can be executed on any local machine with `Docker` installed too.



In the next section is covered on how to the tests are ran, and how to run then locally. 



# Running the tests



The tests are ran primarly in the `Gtihub Actions` pipeline CI with the help of a customized `Dockerfile` build, that will install the necessary packages and the right pip requirements. Besides the pipeline, the same commands can be ran in a local environment, such as the following:



The command below is used to build and run the docker container for the `CentOS Linux 8`.



```bash

$ docker build -f dockerfiles/centos8.Dockerfile -t centos-tests:latest 

$ docker run centos-tests:latest make test

```



And for the `Fedora Linux 34`, this is the equivalent command.



```bash

$ docker build -f dockerfiles/fedora34.Dockerfile -t fedora-tests:latest 

$ docker run fedora-tests:latest make test

```



# Additional stuff



This project was developed on a running `Fedora Linux 34` in my personal laptop.



Build information as follows: 



```

[r0x0d@fedora rhel-migrations-interview]$ uname -a

Linux fedora 5.13.12-200.fc34.x86_64 #1 SMP Wed Aug 18 13:27:18 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

```



And the list of kernels installed on my machine based on the command `rpm -q kernel` as follows: 



```

[r0x0d@fedora rhel-migrations-interview]$ rpm -q kernel

kernel-5.12.15-300.fc34.x86_64

kernel-5.12.17-300.fc34.x86_64

kernel-5.13.4-200.fc34.x86_64

kernel-5.13.6-200.fc34.x86_64

kernel-5.13.8-200.fc34.x86_64

kernel-5.13.9-200.fc34.x86_64

kernel-5.13.10-200.fc34.x86_64

kernel-5.13.12-200.fc34.x86_64

```