Category: Computers

All things computing.

[SOLVED] Unable to Sign-In to Gmail with Thunderbird with OAuth2, Keeps Asking for Email or Phone Over and Over

Posted on by rchapin

If you are setting up Thunderbird to use your Gmail account you may find that when Thunderbird opens a new window to a Google web portal into which you are to provide your email address and password that it will keep asking you over and over again for your email and never enable to you to enter the password.

This occurs when Thunderbird’s privacy settings do not allow it to store cookies.

First, ensure that your gmail account has Allow → Continue reading “[SOLVED] Unable to Sign-In to Gmail with Thunderbird with OAuth2, Keeps Asking for Email or Phone Over and Over”

Edit a Range of Lines Using sed

Posted on by rchapin

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”

Mocking an HTTPS RESTful endpoint with Netcat

Posted on by rchapin

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

Posted on by rchapin

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

Posted on by rchapin

Following are 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.

Most of this article deals with the concept of setting an expiration date on a set of keys to a reasonable time and how you can update that key as time goes by.  You should set a reminder in whatever calendar system you are using to remind you to → Continue reading “Creating, Updating Expiration of and Posting PGP Keys”

How To Compile and Install New SELinux Plicy Modules

Posted on by rchapin

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

Posted on by rchapin

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”

[SOLVED] Unable to Customize Keyboard Shortcuts for Switching Between More Than 4 Workspaces in GNOME on CentOS 7 or RHEL 7

Posted on by rchapin

I am working on a VM that is running GNOME under RHEL 7 and I typically run with 12 workspaces.  The default GNOME install only has the keyboard shortcut configurations up to “Switch to workspace 4”.

It turns out that the solutions is to use the gsettings cli tool to add additional shorcuts.

$ gsettings set org.gnome.desktop.wm.keybindings switch-to-workspace-5 "[\"<ControlF5\"]"
$ gsettings set org.gnome.desktop.wm.keybindings move-to-workspace-5 "[\"<Alt5\"]"
→ Continue reading “[SOLVED] Unable to Customize Keyboard Shortcuts for Switching Between More Than 4 Workspaces in GNOME on CentOS 7 or RHEL 7”

How to See SELinux Denials That Do Not Show In the audit.log

Posted on by rchapin

Or, otherwise know as: SELinux and Silent Denials.

Sometimes when troubleshooting SELinux issues, you will have added new policies for each of the denial causes written to the audit.log, but SELinux will still be denying access . . . and not giving you any further information about it in the audit.log.

Various processes often execute additional system calls that are above an beyond what they need to do for normal operation.  Many of them are blocked, and in order to → Continue reading “How to See SELinux Denials That Do Not Show In the audit.log”

© 2005 Ryan Chapin