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João Silva Xplouder

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There are 18 questions in total. You will need five RHEL 8 (or CentOS 😎 virtual machines to be able to successfully complete all questions.

Optional Automatic Exam Setup Available

Here is an automated exam environment deployment for Mac/Linux/Windows that deploys the practice exam environment for you, including IPA server/client installation and configuration. You can also use your own lab environment. Navigate to the respective repo you wish to use for this practice exam and follow the README instructions:,,

sergeyklay /
Last active Sep 8, 2021
Journalctl Cheat Sheet

Journalctl Cheat Sheet



To see messages from other users and the system as well as performing various log operations from a regular user add it to the group:

sudo usermod -aG systemd-journal $USER
pirate /
Last active Nov 25, 2021
Backup a docker-compose project, including all images, named and unnamed volumes, container filesystems, config, logs, and databases.
#!/usr/bin/env bash
### Bash Environment Setup
# set -o xtrace
set -o errexit
set -o errtrace
set -o nounset
set -o pipefail
npearce /
Last active Nov 27, 2021
Amazon Linux 2 - install docker & docker-compose using 'sudo amazon-linux-extras' command

UPDATE (March 2020, thanks @ic): I don't know the exact AMI version but yum install docker now works on the latest Amazon Linux 2. The instructions below may still be relevant depending on the vintage AMI you are using.

Amazon changed the install in Linux 2. One no-longer using 'yum' See:

Docker CE Install

sudo amazon-linux-extras install docker
sudo service docker start
zfael / nodejs.checksum.js
Created Jun 20, 2017
NODE.JS - How to generate file's Checksum (CRYPTO)
View nodejs.checksum.js
var fs = require('fs');
var crypto = require('crypto');
fs.readFile('file.pdf', function(err, data) {
var checksum = generateChecksum(data);
function generateChecksum(str, algorithm, encoding) {
return crypto
ChuckJHardy /
Last active Apr 5, 2021
Gource Recording for Git

Install Gource

brew install gource

Convert Quicktime Movie to Animated Gif

ffmpeg -i -s 600x400 -pix_fmt rgb24 -r 10 -f gif - | gifsicle --optimize=3 --delay=3 > out.gif

Record Gource

voxxit /
Last active Apr 19, 2021
Consul + Vault + MySQL = <3
git clone vault
cd vault
docker-compose up -d
export VAULT_ADDR=

Initializing a vault:

vault init
denji /
Last active Nov 27, 2021
NGINX tuning for best performance

Moved to git repository:

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

denji /
Last active Nov 27, 2021
HTTP(S) Benchmark Tools / Toolkit for testing/debugging HTTP(S) and restAPI (RESTful)
baojie /
Created Jul 21, 2013
Python multiprocessing hello world. Split a list and process sublists in different jobs
import multiprocessing
# split a list into evenly sized chunks
def chunks(l, n):
return [l[i:i+n] for i in range(0, len(l), n)]
def do_job(job_id, data_slice):
for item in data_slice:
print "job", job_id, item