System & Network Admin

When you get a certificate from Let’s Encrypt, our servers validate that you control the domain names in that certificate using “challenges,” as defined by the ACME standard. Most of the time, this validation is handled automatically by your ACME client, but if you need to make some more complex configuration decisions, it’s useful to know more about them. If you’re unsure, go with your client’s defaults or with HTTP-01.

In the following examples, I'll show how to renew certs with domains hosted on AWS/Route53 and GoDaddy. I run certbot with scripts within a docker container (to simplify automation), however you can use CLI.

How to obtain a Let's Encrypt certificate through a DNS Challenge.

My domain is: https://arenlor.com/ I ran this command: certbot certonly --rsa-key-size 4096 --staple-ocsp --server 'https://acme-v02.api.letsencrypt.org/directory' --dns-rfc2136 --dns-rfc2136-credentials /etc/letsencrypt/rfc2136.ini -d arenlor.com -d '*.arenlor.com' It produced this output: Saving debug log to /var/log/letsencrypt/letsencrypt.log Plugins selected: Authenticator dns-rfc2136, Installer None Obtaining a new certificate Performing the following challenges: dns-01 challenge for ar...

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Simplify the complex world of interface configuration files with this handy tutorial.

EnigmaBBS is a simple yet powerful modern BBS software for Linux. Learn how to install it today and relive the BBS experience of the 90s.

Here are some tips and tricks to automating file edits from the Linux command line.

No one wants to write bad code, but inevitably bugs will be created.

Rate Limiting With nginx. This article explains how to use the nginx HttpLimitReqModule to limit the number of requests for a given session. This is u...

The fmt command is a trivial text formatter. Here's how I use it to format text and email replies.

Jack Wallen walks you through everything you need to know about masked services in Linux.

In this article, we will be more interested in the dwebp command-line tool to successfully convert our sample raw WebP image file to PNG and JPEG image files.

Secure Login with FIDO2

Comparing directories in Linux might seem like a light and dismissive task for a user just starting to explore the milestones associated with using Linux.

This article describes how to mount and unmount an ISO image on a Linux Operating system to access and list the content of files.

CLI is more productive than GUI

Replace your notebooks and printed documents with the only tablet that feels like paper.

Bring all your calendars together on Windows, Mac, and Linux. Integrated Tasks and Scheduling links. Get started for free.

Mailspring: The open-source, extensible email app for Mac, Linux, and Windows with open tracking, link click tracking, contacts enrichment data and more.