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Basic Website Development Tools Every Blockchain Developer Needs

Mon, 05/09/2022 - 21:02 — Alexis Wilke

Developers can choose from many advanced software applications in today’s environment of intensive research on potential uses for blockchain technology. Web development tools include Ethereum DApps Development where researchers and developers strive to build decentralized apps and smart contracts. Smart contracts have the built-in ability to adjust based on changes to key terms and to monitor compliance with the terms of the contract.

Blockchain development tools help to facilitate software development. If a developer is new to blockchain or lacks experience, he or she should become ...

Don't Repeat Yourself When Writing Software

Fri, 05/01/2020 - 10:39 — Alexis Wilke

Nature tends to repeat itself, or reproduce with similar structure, but code should not.

For a very long time now, we have been using languages that support having functions that one can call. That was not always the case, although even really old versions of BASIC had a GOSUB instruction, which it had no concept of local variables so it was rather difficult to use safely.

Functions allow you to avoid repetition. You write a small snippet of code (or maybe not that small) within a function and then you call that function to reuse that snippet over and over again. Good programmers tend to do that even with one liners. However, many others often think: well, it's just one line, why don't I return copy & paste that wherever I need it, it's going to be faster.

Docker, an advanced chroot utility

Fri, 11/29/2019 - 18:09 — Alexis Wilke

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.

Brief Overview of CRISC Certification Exam

Sat, 06/23/2018 - 13:08 — Alexis Wilke

The CRISC, also known as Certified in Risk and Information Systems Control, is a vendor-neutral certification that validates a professional’s knowledge and experience in the fields of information system control & risk management. The certificate is developed and administered by ISACA and designed for the individuals who work with organizations in mitigating business risks and implement information system controls.

Organizations in today’s world must consistently enhance their infrastructure so that they can survive and thrive in today’s competitive environment. It is a ...

No more excuses! Protect your passwords on your computer with strong encryption.

Wed, 02/14/2018 - 17:05 — Alexis Wilke

More and more, we hear talks about hackers entering personal accounts on systems such as Facebook, Twitter, Instagram and many others. There are many reasons why someone's account will be hacked. One of them is the lack of imagination for their password. Plus, some people use the same password for all of their accounts.

So, if you do it right, you will end up with many passwords. On my end, I have one password per account and that means about 400 passwords... That's totally unmanageable in a fairly standard human brain. For this reason, you end up writing down all your passwords on ...

Avoid automatic translation of Facebook posts

Sun, 12/31/2017 - 15:50 — Alexis Wilke

Once more today my French friend's post was translated.

French is my mother tongue so I sure don't need the automatic translation for French on my Facebook wall. I also like to read a couple other languages, even if I'm not at the best level I only need a little help with a few words here and there, so I like to have those in the original language to improve. The more you read a language the more you learn about it. Same if you live in a country and start talking with people there. You're going to learn a lot more that way than staying at home and not talking to anyone any ...

South Sudan top-level domain is .ss

Tue, 09/13/2011 - 10:20 — Alexis Wilke

Very recently, Sudan was split in the northern and southern part. The southern part has a new name: South Sudan. It is now official and the new ISO country code given to this new country is SS.

This means their country top-level domain name will be .ss.

Assuming they open their domain name to all world wide, this is going to be quite interesting! There are many words in the English language that end with .ss such as dre.ss, and stre.ss, and le.ss...

If you're in the domain name business, look out for those! If it works like other top-level domains, these will go really quick and make ...

Table of Contents Settings

Filter Configuration

At this point, most of the Table of Contents configuration is done in the Table of Contents filter.

This means multiple Input formats allow you to make use of several different configurations.

End

Read more

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