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How small are computers getting?

Mini-computer versus Mouse

Click on picture to see on Amazon.com (which I'm an affiliate of).

Computer Stick

Looking at Mini Computers, I found this Fanless Mini PC based on the Intel Atom Z8350 processor by SmallRT. The picture includes a mouse to give you an idea of the size of that thing. It's tiny! Maybe not what you want, but you can already do a lot with that little one.

The connector on the left side is an HDMI plug which spits out 4K of video graphics. It's just totally amazing to me. Of course, we had the Pi3 and now we have the Pi4... but those are computers for hackers. Here we're ...

Docker, an advanced chroot utility


Chasm—just like a Docker creates a chasm between two sets of software

SECURITY WARNING

Before installing Docker and containers with services on your Linux system, make sure to read and understand the risks as mentioned on this Docker and iptables page. Especially, Docker will make all your containers visible to the entire world through your Internet connection. This is great if you want to indeed share that service with the rest of the world, it's very dangerous if you are working on that container service since it could have security issues that need patching and such. Docker documents a way to prevent that behavior by adding the following rule to your firewall:

iptables -I DOCKER-USER -i eth0 ! -s 192.168.1.0/24 -j DROP

This means that unless the IP address matches 192.168.1.0/24, the access is refused. The `eth0` interface name should be replaced with the interface name you use as the external ethernet connection. During development, you should always have such a rule.

That has not worked at all for me because my local network includes many other computers on my LAN and this rule blocks them all. So really not a useful idea.

Instead, I created my own entries based on some other characteristics. That includes the following lines in my firewall file:

*filter
:DOCKER-USER - [0:0]

-A DOCKER-USER -j early_forward
-A DOCKER-USER -i eno1 -p tcp -m conntrack --ctorigdstport 80 --ctdir ORIGINAL -j DROP
-A DOCKER-USER -i eno1 -p tcp -m conntrack --ctorigdstport 8080 --ctdir ORIGINAL -j DROP
-A DOCKER-USER -i eno1 -p tcp -m conntrack --ctorigdstport 8081 --ctdir ORIGINAL -j DROP

My early_forward allows my LAN to continue to work. These are my firewall rules that allow my LAN computers to have their traffic forwarded as expected.

Then I have three rules that block port 80, 8080, and 8081 from Docker.

Docker will add new rules that will appear after (albeit not within the DOCKER-USER list) and will open ports for whatever necessary service you install in your Dockers.

Note that the only ports you have to block are ports that Docker will share and that you have otherwise open on your main server. If Docker opens port 5000 and your firewall does not allow connections to port 5000 from the outside, then you're already safe. On my end I have Apache running so as a result I block quite usual HTTP ports from Docker.

Docker

As we are helping various customers, we encounter new technologies.

In the old days, we used chroot to create a separate environment where you could have your own installation and prevent the software from within that environment access to everything on your computer. This is particularly useful for publicly facing services liek Apache, Bind, etc.

Icecream Locks?!

I like technology, but I think that at times, it just goes too far.

Today I found out that a company is actually selling an Ice Cream Lock. Yes! A lock so people can't easily open your ice cream, at least not without either picking the lock or breaking the ice cream box.

It's a simple lock with a combination and if you don't know that combination, you just won't be able to open the ice cream box. Here are some pictures:

Locked Ice Cream

Click the image to see more on Amazon.com
(Note that I'm an affiliate)

Now, I really think technology is going too far! indecision

Enjoy!
Alexis

Best C++ Books

Once in a while someone will ask me which book is best to start learning programming. The fact is that I do not know because I'm already an advanced programmer and it's rather difficult for me to get back to the basics (it feels like a waste of my time, sorry...)

That being said, at Made to Order Software, we've mainly been a C++ shop. We also do a lot of C, PHP, JavaScript and touch many other languages as required by the tasks we perform (bash, cmake, perl, C#, Java, etc.)

That being said, I wanted to underline some of the best C++ books available today. Especially, in the last ...

Terms & Conditions

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Amazon Checkout and Simple Pay

This week, Amazon published a brand new set of tools for merchants. We already had PayPal and Google Checkout, now we have the same with Amazon.