Category Archives: RedHat and Friends

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Don’t forget! Linux Learning Resources

This is kept under the Linux Learning Project and Learning Resources section of the site, and is updated occasionally with new links.  Feel free to suggest one by contacting me directly.


LEARNING RESOURCES

Help/Chat:

Resources:

Need DevOps Help?

  • Had issues with your DevOps pipeline?
  • Need help streamlining automation or configuration management?
  • Need to green field or “lift and shift” applications into the cloud?

If you are trying to do any of these, and running into issues please contact me.  I am now open to consulting directly.  Fixing even a few small inefficiencies can have a huge impact on the bottom line.  Not only that, if the DevOps philosophies are really taken up, its likely that the employee base will also be happier, and proud of their accomplishments as a team.

As far as technologies I support, please take a look at my Technologies page.  (Updated often)  I am also happy to take on new ones for a project if needed.

Creating an efficient pipeline is what I do; and a fully functional system that is working well can be an amazing thing.

 

Matthew Curry
MattCurry.Com

 

The Eagle Has landed….

All,

I have made it…. the move is complete!   I just wanted to say thank you for everyone that has been waiting on me.  I know I have taken a while on a few things, and I am finally in a position to run with everything again.  I finally have a decent internet connection [330mbps/330mbps]; so I will also be able to host things at high speed for us now as well.

As far as the installer goes, I hope to be done very soon with it ;  I am putting my final touches on it for the Pixel desktop.  If I get time I might be able to get Bluetooth working!  However, I have to get caught up first.

For those waiting on hardware, most has been shipped with a few exceptions.  I have notified those people.  I have a true ‘shop’ area again, and this will allow me to be much more efficient.  Meaning shorter wait times/etc…

 

Sincerely,

-M

A few BASH tips from an old Linux admin.

Everyone has seen these “Top 50 commands” blah blah blah….. #clickbait….

I am writing this just to make BASH a much more pleasant experience for people new and old to Linux.  It is also for any sysadmin that has simply not been introduced to some of them.

I could list tons of them, but that’s going to get a simple TL;DR for most people.  Then they will move on.  So I will list a few and lets let those digest.  Keep in mind all commands are in Linux, and may vary by distribution.

First BASH tips (Simple, but time savers):

  1.  Type ‘cd’ and you will go to your home directory for the user you are logged into.
    1. Similar to “cd” ~, however ~ can sometimes rely on the environment.
  2. To return to the previous directory you can type ” cd -“.
    1. This will return you to your previous location, not home.
  3. Type “tailf”, instead of “tail f” for the same results.
    1. Also, “tail -200” can be used instead of “tail -n 200”
  4. Use a custom “PS1” for root, and regular users.
    1. A “PS1” is the text in the login prompt. See Example to the right:
      1. Notice it is yellow
      2. Do the same but in red for root.
    2. Examples:
      1. Debian PS1 for a normal user (as seen to the right)
      2. Debian PS1 for a ROOT user.
        1. These will need to be added to the bottom of “.bashrc” in your home directory
        2. Keep in mind files starting with a . are hidden in Linux, but there.
          1. I also have MAC PS1’s public in my gists.

 

I think that is enough for today, I hope this helps make BASH your friend.

 

-M

12 Years without Microsoft and loving it!

As of April, 2004 I stopped using all Microsoft products.

For many reasons. I know people like to debate about microsoft products. However, for me its not a debate.

Examples [Just a tiny bit]:

  • If I was a contractor and came into your company and said, “I am going to record all your keystrokes, and put them on my server every 30min”, you would laugh me out the door. Especially in software, where the source can be recreated from the key logs.  Well, Microsoft does it.
  • If I was a contractor and came in to your company and found a security bug, and then sold it on the black market making you vulnerable before there is a patch to hackers.  You would probably sue me; and maybe even press charges of some kind, as it can put you out of business.  Well, Microsoft does it.
  • If I was a contractor and came in during the night and upgraded all your desktops to an OS you haven’t tested… well I think you get the point by now…
  • UEFI – Just look into it…
  • Severe security issues; and poor coding.
    • Keep in mind even if they don’t use the keylog maliciously, with the poor security wrapped around it, it is within reason to think it would be compromised.

Please keep in mind I am just looking at the black and white of things. This has nothing to do with how I ‘feel’ about them.  From a business standpoint, I can not simply fathom the use of any Microsoft product in any serious company; especially a software development one.

Now, I am experienced in IT/Software Development/DevOps; and anyone will tell you security is a trade off with convenience.  That is true.  However, between the cost (which is high); and the constant worry about security and stability with each patch.  Its something people really need to ask themselves, ” Is this really convenient/cost effective”; and 15 years ago it might have been yes. Now, there is no excuse.

 

Be Careful with LetsEncrypt!

 

I must say, like a lot of people I love the idea of a free SSL Certificate.  So I thought this would be great for my site.  So I downloaded the LetsEncrypt package on to an Ubuntu 15.10 box.  The server was running Apache2, and was pretty much stock.  When I applied the cert to the site, it was super easy.  I was very impressed with the ‘–apache’ option.  I then updated my URLs in WordPress to HTTPS.  That’s it I was up and running in a few min.  I was pretty happy at this point.

Then, I realized it broke all of the other services I had on the machine that were public facing.  I had several.  Even ones with their own certs were breaking.  So I decided to remove it…. After removing it from Apache completely I noticed an issue.  All of my users that had been to the site; were getting redirected still.  Somehow it is keeping the redirct with the cert/data that is installed when the cert is installed from visiting the site.

Long story short, I had many people that thought my site was down.  I even moved servers; and it still happened. I tried clearing browser cache, DNS Cache on my MAC, from another IP. Finally after a reinstall (probably not needed, but quicker); I was able to actually load my site without the redirect.  I am sure there is something here I am not seeing; but to be honest I didn’t feel like spending all my time dealing with browser settings.

If anyone would like to let me know how they get around this I would like to know.

I hope this helps those who are thinking of trying out LetsEncrypt.  I am not saying its a bad product; or idea.  I love the install and the idea of it.  However, the practical implementation is not there yet.  For those reading this keep in mind that it is still in Beta as of this article.  So this might eventually go away.

P.S. – To those on the LetsEncrypt project, I appreciate all the work; and I hope you take this criticism positively. A good uninstall path is needed before I think this will go mainstream on monolithic boxes.  Maybe its ok with a 12 factor applications.

Sincerely,

Matthew Curry

Top 10 Most Powerful Computers in the World!

As some people may know; I like to use the example of  “Out of the top 500, how many supercomputers in the world do you think  use [your OS here]?”.  I use this example for a reason.  Unlike conjecture, theories, and even “gut feelings”; it shows that the OS was chosen, and serious money and time were poured into it.  This shows that is it at least a player in the field, and can handle the serious levels of computing needed.  It also shows things like, tune-ability, flexibility with change, and a few other things that only the people working with their own projects will be able to tell.  We are not concerned with that, just that they are on the list; and why if it sticks out as odd to see why.

I am using the TOP500 Project for this information, and it does get re-evaluated often.  However, I will say this; just like in nature there will always be a pretty clear delineation when it comes down to who is the “Winner” in this space.  Or the most efficient/successful like in nature.

The reason I write this article is to show a certain group of people an example of the difference in reality versus what advertisements, rumors, and self-perception have molded in their minds.  I think it is a good exercise to show the affects of the budgets used to change our perceptions. A good example is the budget used by companies like Microsoft (over $2,000,000,000); and Apple (over $1,000,000 in 2013/2014).  This is just money, and perception however.  This will never affect real life numbers on performance, math doesn’t lie. Results and time are my favorite sources of information.  Its a simple concept, there are 1000s of ways to move items.  However, in our lives in this age of technology the wheel is still very much in use.   Its the best solution at the time…. (a small but powerful statement).

So in lieu of keeping you away from the data pron you came to look at:

 

Top 10 Super Super Computers - Nov 2015

Top 10 Super Super Computers – Nov 2015

 


 

Here is the actual breakdown by OS (as of Nov 2015), as I know that is what most people are interested in:

List_Statistics___TOP500_Supercomputer_Sites

 

I know some people are wondering where is Windows, or IOS.  If you will notice; even in the breakdowns by OS they are pretty much all Linux/BSD [Windows isn’t even a filter option on their site as of right now].  This list is more a list of flavors of Linux with a few BSD machines in the list.  You will notice, like in most of the lists done in the past; there is not a single Microsoft product on the list.  This is a very simple, and very important fact that way too many people make.  This includes everyone from the guy that fixes your desktop all the way up to the VP of Infrastructure.  They are all swayed by what they own, and the amount of advertising spewed forth at them non-stop. Keep in mind these people are generally more connected than the rest of the populous.  Thus, affected even more so by the ads.  Combine that with sales people/calls/pressures on support/etc, and you get smart companies ( I didn’t say large), that make really bad technology decisions.  I exclude myself from that ad loop; and look purely at statistical performance.   This is great for business; since you can eliminate a TON of costs; and licensing fees/etc that you would have if you went with something not on this list.

 

List_Statistics___TOP500_Supercomputer_Sites 2


 

Want to see the full list of over 500 super computers for 2015?

Search entire server for Q4 2015 obfuscated PHP malware of unknown origin.

This is just a snippet I have used before to identify some malicious code on web servers.  This will not work on everything; but it will give you a way to find suspect files.  It is easy to cron in a script with others to make a nice daily report if you have those concerns.

#!/bin/bash
# Malware Search Script
# 11/1/15 – Matthew D. Curry
# Matt@MattCurry.com

echo “Search entire server for Q4 2015 obfuscated PHP malware of unknown origin.”

find / -name *.php -exec grep -Hn .1.=…….0.=…….3.=…….2.=…….5.= {} ;

 

Hope this helps, enjoy.

Want to use DNF? What to expect…

DNF actually DOES stand for something… Not sure where that started.

DNF stands for Dandified yum

DNF started showing up in Fedora 18, and Fedora 20 was the first Linux distro that welcomed users to utilize  DNF in place of YUM.

The technical challenges of DNF are that there is little or no support for features:

  • Debug
  • Verbose output
  • Enable Repository
  • Exclude packages during install
  • No effect of –skip-broken switch
  • The command resolvedep unavailable
  • The option skip_if_unavailable is ON by default
  • Dependency resolving process is not visible in Command Line
  • Parallel downloads in future release
  • Undo History
  • Delta RPM
  • Bash completion
  • Auto-remove
  • many others…

 

In short, if you drink the cool-aid then you should run this in a lab only.  I know people that try to run this stuff in production.  You are just asking for a serious problem. Other than that, I hope it gets there, DNF is just too new.