How to Find Ingested Foreign Objects in Poop

Admittedly, not the most savory subject. But, for those of us with pets and/or children it is sometimes a necessity to try to find a previously ingested foreign object in feces to make sure that it does not cause medical problems in the person or animal that has accidentally eaten it.

Recently, we thought our dog had eaten a relatively small magnet and figured that we would have to be checking his feces over the next few days to ensure → Continue reading “How to Find Ingested Foreign Objects in Poop”

Edit a Range of Lines Using sed

Let’s say that you have a range of lines in a source file (lines 11 – 17) that you want to comment out with a ‘#’ and a space character before the line.

To do that, you would use sed, specifying a range of lines and then specify a replacement command with a capture group as follows:

sed '11,17{s/\(\w\)/\# \1/}' filename.py
Continue reading “Edit a Range of Lines Using sed”

Notes on Forming, Mixing, Pouring and Curing Concrete

DISCLAIMER:  These are my own notes learned from my own trials and tribulations of building things with concrete.  They are in no way, shape or form to be taken as an expert opinion.  Follow what you read here at your own risk.  This is mostly notes to myself as I work through learning how to build things out of concrete.

Big Lessons Learned

Helpers

Doing this by yourself is painful.  For anything more than a small job you absolutely need → Continue reading “Notes on Forming, Mixing, Pouring and Curing Concrete”

Mocking an HTTPS RESTful endpoint with Netcat

Netcat is generally known as a TCP/IP Swiss Army Knife and is incredibly helpful for both debugging and mocking up network services

Following is an example on how to setup a mock RESTful service that communicates over HTTPS.

On the “server” side, run the following command.  The -l command instructs Netcat to listen.

while true; do { echo -e “HTTP/1.1 200 OK\r\n$(date)\r\n\r\n<h1>hello world from $(hostname) on $(date)</h1>” |  nc -vl –ssl 8080; } done

On the “client” side, run the → Continue reading “Mocking an HTTPS RESTful endpoint with Netcat”

Test Network Speed of Ethernet Ports

If you have just bought a new (to you) nic card or other networking device and want to test that all of the ports can pass traffic at the expected rate, as long as you have nc and the firewall ports open on a “server” with a known good nic and have nc installed on your “client” device that you want to test it is very easy to test.

Of course, if you are testing a switch itself, then it → Continue reading “Test Network Speed of Ethernet Ports”

Creating, Updating Expiration of and Posting PGP Keys

Following are some of my notes and how-tos on creating, and managing PGP keys.

Here is a link to a website with some very good information and best practices for managing keys:
https://help.riseup.net/en/security/message-security/openpgp/best-practices

Most of this article deals with the concept of setting a expiration date on a set of keys to a reasonable time and how you can update that key as time goes by.  Separate to the creation and publishing of your public key, you should set a → Continue reading “Creating, Updating Expiration of and Posting PGP Keys”

How To Compile and Install New SELinux Plicy Modules

Following is a quick how-to on compiling and adding addition SELinux modules.

When configuring and deploying new and/or custom services on systems that are enforcing SELinux you will likely have to compile addition SELinux modules.

This how-to includes how to go through each step of compiling a new module one-by-one; similar to the model of breaking down the compilation of C and C++ into it’s composite steps.

Step 1:  Gather the audit.log entries

You will need to determine which → Continue reading “How To Compile and Install New SELinux Plicy Modules”

Adding a New Disk to a Linux Server and Creating an LVM Partition

There are a number of tutorials online for adding a new disk to a machine and then extending an existing LVM partition to use the new device.

This particular tutorial covers the use case of adding a new disk to a Linux server and then creating a NEW LVM partition on it without modifying the existing devices and LVM partitions.

The first thing you will need to do is add the physical device to the server (or VM).

Then, you → Continue reading “Adding a New Disk to a Linux Server and Creating an LVM Partition”