Category Archives: Linux

Let’s Encrypt! Checking your HTTPS certificate expiration date

Let’s Encrypt offers free HTTPS certificate for your website.  The catch is that they are valid for only 90 days so the certificate has to be renewed four times a year. The instructions here have made it painless to automatically renew the certificates via … Continue reading

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Windows – Registering Putty for SSHS:// custom URI Scheme

One of things that I do to simplify my job is to maintain a local webpage listing servers that I can SSH into.  With Windows, I can register the sshs:// URI scheme to putty.exe Windows executable.  Any links starting with sshs:// will be … Continue reading

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Ultimate NGINX reverse proxy to WordPress / PHP / Python / Django / Golang / Flask

For years, I’ve relied on Apache web server on my personal machine to continually hone my web programming chops and it doesn’t hurt to readily have a working server configuration for quick reference. While Apache has performed brilliantly, it was time to switch and … Continue reading

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Mobaxterm – setting up Git with CA certificate bundle

On my Windows machine, I use Mobaxterm, which is a great environment based on Cygwin and gives me an UNIX-like alternative to Windows command window. Git can be set up but needs some configuration first before it’ll work flawlessly. … Continue reading

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Watching in real-time IPv4 network interface changes

Note: I ignore local loopback and virtual networks.  Your setup may be different. watch -n 1 ‘ip addr | grep inet | grep -v inet6 | grep -v “” | grep -v  192\.168\.76 | grep -v 172\.16\.  | awk ‘\”{print … Continue reading

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Useful: how to move a running process into a screen terminal

One of the useful things about using screen (a terminal multiplexer) console is that you are able to detach from the screen terminal while keeping your running session alive.  At a later time (such as when you arrive home from … Continue reading

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Ubuntu: How to select and install (or pin) a package from a repository

This is a follow-up to “Redis and php-resque on Ubuntu 12.04.” Why pinning a package may be desirable In my previous post, after adding the repository to an Ubuntu system, then performing an system-wide upgrade,  mysql-server and php (if … Continue reading

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Redis and php-resque on Ubuntu 12.04

During my free time, I help to administer a machine hosting several websites which generate copious amount of traffic and at times, there can be a significant load on the server. These websites require many tasks running on the back … Continue reading

Posted in Databases, Linux, Programming, Web/Tech | 2 Comments

How to access the text console of a virtual KVM guest from within virsh

(done on clean installation of Ubuntu 11.10/KVM) After getting a KVM host up and running on Ubuntu, often the graphical VM management application, virt-manager, is installed.  This useful utility makes it a snap to create new virtual machines and gives … Continue reading

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Inception problem: keymap for ‘a’ key broken inside twice-virtualized Ubuntu KVM guest

Running an Ubuntu virtualized virtual guest inside a virtual KVM host inside VMware Fusion 4 for OSX? You may have noticed that when ssh -X to the virtual KVM host machine then attaching to virtual guest graphic console (VNC) via … Continue reading

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Adding custom launchers to Ubuntu Unity launcher bar

For Ubuntu (11.04) desktop, I like to have a custom launcher to start ‘gksudo /usr/bin/wireshark’ At this time, it’s aggravating to use the Unity launcher bar (until they get their act together). There’s no support to add custom launchers to … Continue reading

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Fixing Windows clock time issue when booting.

I’ve been putting up with a slight annoyance when I dual-boot back into Windows from Ubuntu: The clock in Windows is always offset by a few hours. The fix: Set a registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\RealTimeIsUniversal to 1 This tells the Windows … Continue reading

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Fedora 15 (64-bit) desktop with Chrome, Flash, Adobe Air, VLC media player

I have hunted down bits of information from the far-flung corners of the Internet and consolidated them into a single post: Improving upon the default Fedora 15 desktop and run popular user applications, such as Google Chrome with Flash plugin, VLC … Continue reading

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Ubuntu: Installing RRDtool 1.4.5 and php->RRDtool bindings

Installing RRDtool 1.4.5: Ubuntu 11.04 repo only offers older RRDtool 1.4.3, so if need to have a more recent RRDtool on your system: Run the following commands as superuser: sudo su apt-get install libpango1.0-dev libxml2-dev wget tar -zxvf rrdtool-1.4.5.tar.gz … Continue reading

Posted in Linux, Networking | 2 Comments

How to call video relay service (VRS) with Linux / Ubuntu

How to call VRS from inside Linux-based OS such as Ubuntu Background information for people not familiar with VRS: Video Relay Service is one of the most useful service provided to deaf Americans. This service enables deaf people to initiate … Continue reading

Posted in Linux, Video, Web/Tech | 7 Comments