Nothing to do this weekend? Here’s ideas for a weekend project.

There’s nothing worse then being bored over a weekend. So in case you’re looking for something to do this weekend, give one of these a try if you have the time and parts sitting around.

Build a Raspberry Pi Buggy – One of the milestones of hobby robotics is a vehicle that is controlled with a Raspberry Pi.

Build an air quality monitor – Great way to get started with Sensors and detecting the world around you.

How to Set Up a Safe and Free VPN on Android – You know to use a VPN on your computer over public wifi, but we should all be doing the same with our phones as well.

So try your hand at building something or just try and make your phone a little bit safer on the open internet.

-DH

Updating all your Docker images in one swoop.


I’ve been playing around with Docker a lot recently, and one thing that seems to be lacking is a way to update all of your downloaded images in an “apt-get upgrade” fashion. I know this isn’t usually needed in most cases, but in a home use case for Docker most of the time, you can upgrade everything in one go and not worry about it. So I wrote some quick one-line scripts in Bash and PowerShell that can be used to update all your docker images. Continue reading Updating all your Docker images in one swoop.

Running a Home Virtual Server – Part 2: Contemplating Containers


Ok, so it’s been awhile since I put up the last part. So long that I actually ended up looking at some other hypervisor options, and still ended up going with Proxmox. I’ve also made it slightly more robust by running two host machines in a cluster configuration. I not running many virtual machines right now, but the ones that I do run are mostly OpenVZ containers from TurnkeyLinux.org, which Proxmox has a built-in integration to download templates straight from them. There are also other OpenVZ templates from Proxmox for a few standard linux server OSes, but the Turnkey Linux ones seem better at being kept up to date. Below the fold is a short list of what I’m currently running and a few that I plan on setting up at some point. Continue reading Running a Home Virtual Server – Part 2: Contemplating Containers

Bash scripts based on running processes


At work, our ERP system is built on Oracle running on a clustered Linux (Red Hat Enterprise) environment. Since this is a high availability/failover setup the processes running our development databases can be on either server for any number of reasons. I wanted to make installing code a bit easier on the server so I made some bash scripts to partially automate the install for me. Not wanting to get errors when it tries to install code on the wrong server, I found this little command to determine if the database is running on a server and thus let the script go on with the install.

ps -U oracle -u oracle u | grep -q pmon_dev2

Lets break this down into each part. The first part, ps -U oracle -u oracle u, gets the currently running processes running as “oracle” (first “-U” for real and second “-u” for effective ID) in a user-oriented format (last “u”). This is similar to an example in the MAN page for PS and I just replaced the usernames to fit my case. The pipe (“|”) takes the output from the left side, the PS command in this case, and uses it as input for the right side. The second part, grep -q pmon_dev2, searches for “pmon_dev2” in the output from PS, the “-q” option suppresses output and exits successfully if any match is found.

So I just put this at the beginning of my script:

if ! ps -U oracle -u oracle u |grep -q pmon_dev2
then
echo "DEV2 not running"
exit 1
fi

This exits the script right away if the database isn’t running on the server. If it is, then the script goes on to get the latest code from source control run the code install and exit. If you can do this with no user input, then you can setup a CRON job to run the script to automatically get any updates.

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We Interrupt Your Regular Broadcast to Bring You This Important Message.


After spending most of this week working with and debugging approximately 8,000 lines of PL/SQL contained in two packages, I want to mention “Refactoring” by Martin Fowler. It’s one of the few books I had to buy in college and have kept since then. If your code smells, clean it up… That is all.

Now back to your regularly scheduled programming.

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Bitcoin Payments with a Click


With recent Bitcoin coverage in the news and media, I’ve picked up playing around with it again. One thing that came to mind was something that would make it easier to make payments to addresses found on the web. My first thought was doing the same thing as a MailTo link on the web, click the link and the client opens up with the details in place. Granted copying and pasting the address isn’t that big of a deal, but this makes it easier to send or donate to a website.

Now I have to be honest I wasn’t sure what the correct name for the MailTo link was called. One quick Google search led me to the MailTo URI Scheme Wikipedia page. Another Google search for “Bitcoin URI Scheme” led me to this page with a technical write up of a URI Scheme for sending Bitcoin payments. Lo and behold, the samples on that page work just like I’d expect by opening the local client on my computer with the address filled in. The only problem I can see is that most sites aren’t using this already. I would imagine that this would be a no brainer, where anything that makes it easier to send you money is always a good idea. So here’s my plea to other sites to add the code needed for the bitcoin link.

Just in case anyone needs a refresher, it’s done with the <a> tag and in it’s simplest form would look like this.

<a href="bitcoin:PutPaymentAddressHere">Link text goes here</a>

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