Random Thoughts

Pre-compiled libraries in nix-shell

2018-01-12T19:01:00.001-08:00

I've been using nix-shell as a way to have an easily reproducible environment. I was using Docker but it's overkill for what I was looking for and it gave me the opportunity to explore the Nix ecosystem a little further.

The project I'm currently working on used Elm for the front-end, Elixir for managing the API and connecting to SQL Server. Microsoft have open sourced the necessary libraries to use ODBC through Erlang so I was able to get it working on my development environment pretty quickly.

The MS libraries are here with complete installation instructions.

However, when I tried to incorporate into my actual project I ran into a few issues. I am using nix-shell to load up my environment so I know that its the same across machines and it's been working very well. After I had everything installed, I attempted to connect to the database only to be informed by the ODBC Driver Manager that /opt/microsoft/msodbcsql/lib64/libmsodbcsql-13.1.so.9.2 did not exist. I checked the filesystem and the file was there so I used the ldd utility to inspect the libraries and found that most of the required libraries could not be found:

$> ldd /opt/microsoft/msodbcsql/lib64/libmsodbcsql-13.1.so.9.2
linux-vdso.so.1 (0x00007fff71ba5000)
libdl.so.2 => /nix/store/.../lib/libdl.so.2 (0x00007f8c4ce9a000)
libodbcinst.so.2 => not found
libcrypto.so.1.0.0 => not found
libkrb5.so.3 => not found
libgssapi_krb5.so.2 => not found
libcurl.so.4 => not found
libssl.so.1.0.0 => not found
libuuid.so.1 => not found
libstdc++.so.6 => not found
libm.so.6 => /nix/store/.../lib/libm.so.6 (0x00007f8c4cb4e000)
libgcc_s.so.1 => /nix/store/.../lib/libgcc_s.so.1 (0x00007f8c4c938000)
libpthread.so.0 => /nix/store/.../lib/libpthread.so.0 (0x00007f8c4c71a000)
libc.so.6 => /nix/store/.../lib/libc.so.6 (0x00007f8c4c368000)
/nix/store/.../lib64/ld-linux-x86-64.so.2 (0x00007f8c4d49a000)

After doing some research I found a few links to help me better understand the problem. From this StackOverflow issue
"So, the path to the dynamic linker is hard-coded in the binary. And the dynamic linker being used is from the system (from the host glibc), not from nix. And because the dynamic linker doesn't match the glibc which we want and need to use, it doesn't work.

A simple and working solution is patchelf."

So I followed along and tried to get these tools to work with the MS libraries but no glory. I kept getting "cannot find section .interp" when attempting to set the interpreter using patchelf. I wasn't able to get past this issue as I had limited time and was already pretty deep down the rabbit hole. I was able to find the source for the MSODBC drivers version 11 but the compiled version was 13 and I was still unable to get the older code to compile. Again, limited time and pressure to move on.

So undoing the nix-shell environment did allow me to get everything working. I hope to have time to figure this out in the future but wanted to post my findings in the event anyone else is experiencing these issues with the MS drivers.

Getting started with erlcloud (Erlang AWS Client)

2013-11-11T19:07:00.000-08:00

I've been reading up on Erlang and wanted to find a project to read through and gain a better understanding the the language. I decided on erlcloud as I'm doing a lot of work with AWS. Here are a few things I learned the hard way in the hopes of saving someone else some time.

After cloning the package from Github, you should run "make" to get all the dependencies and compile the code. Rebar should work as well.

Make sure to check out the README file and setup your AWS credentials so they can be found.

To get everything started in the shell, you need to tell Erlang where to find the beam files:
MBP:/home/code/erlcloud$ erl -pa ./ebin -pa ./deps/jsx/ebin

Then once in the shell:
ssl:start().
erlcloud:start().
erlcloud_ec2:describe_images().

I'm guessing there is any easier to get all this started but I'm still learning.

Functionally Thinking ...

2013-09-09T15:02:00.002-07:00

I've been trying to better understand functional programming for a while and wanted to document the steps.

Think about expected results, not steps to get there.

1. Learn you a haskell
2. http://www.learnprolognow.org/
3. PrgProg's Elixir book.
4. O'Reilly's Elixir book.
5. Some Erlang research ...
6. PeepCode Elixir intro.
7. http://www.ibm.com/developerworks/library/j-ft1/

Good Talk by Neal Ford!

Tangible Function Functional Programming

I'll come back and update further as I better understand the concepts.

Willful Blindness

2013-08-13T13:19:00.000-07:00

Aug. 12, 2013

Margaret Heffernan: The dangers of "willful blindness"

Gayla Benefield was just doing her job -- until she uncovered an awful secret about her hometown that meant its mortality rate was 80 times higher than anywhere else in the U.S. But when she tried to tell people about it, she learned an even more shocking truth: People didn’t want to know. In a talk that’s part history lesson, part call-to-action, Margaret Heffernan demonstrates the danger of "willful blindness" and praises ordinary people like Benefield who are willing to speak up. (Filmed at TEDxDanubia.)

What is Leadership?

2013-06-22T08:24:00.000-07:00

via Caesura Letters

Leadership Doodle

By James Shelley

This is one of my favourite napkin doodles:

I draw a circle to represent “a goal”. Another circle to represent “the people”. An arrow pointing from the “people circle” to the “goal circle”.

The question: what is leadership?

What does it mean to move people — the rather finicky creatures that we are — to actually do something together?

Push. It seems that some leaders get behind the people circle and push it towards the goal. Well, they call it “encourage,” actually. Nelson Mandela said, “It is wise to persuade people to do things and make them think it was their own idea.” (Stengel, 2008) Classic push-leaders often find second careers as motivational speakers: “Yes, you can do it!” is their primary message.

Pull. Some leaders get in front of the people circle and pull everyone along, in a way that conjures up the stereotypical image of an alpha personality, akin to the image of a face-painted William Wallace persona leading the charge. In less euphoric times these are the leaders who, in the words of John Naisbitt, settle for “finding a parade and getting ahead of it.” (Naisbitt, 1982) When they are actually sitting still they are busy fine-tuning endless drafts of vision, purpose, objective, and mission statements.

Insiders. Some leaders like to dive into the people circle and lead from within. Disciples of Dale Carnegie and John Maxwell come quickly to mind. These are the people who are out to save corporate America one coffee appointment and “checking in on you” email at a time. Of course, we all love these kinds of leaders—and we know full well that these leaders love for us to love them too.

If I am the crunched up end of a coffee stir stick, bouncing around the metaphorical napkin of leadership, I find myself most in sync with my convictions when I just ignore the people circle altogether and move myself toward “the goal” circle. Trying to manipulate and alter people’s thinking (not to mention their habits) is hard work, in fact it is a never-ending pipe-dream into which one can easily flush many years.

Ironically, most of the leaders who we revere as our idols did not invest their lives into trying to subvert the conscious landscape of the people circle. No, the greatest leaders in history seem to have just gone after the goal because they believed in it. The following hypothesis lands outside of the realm of provability, but perhaps it carries anecdotal truth nonetheless: humans seem almost lustful to follow an individual with an audacious, personal commitment to practical action.

We instinctively want to trust leaders who are really going to “make it happen” — so it seems logical that there is no leader more enticing than the one who is already doing it. We know that the leader who cares the most is the leader who will die for the goal, even if no one else is following. Yet, these are the people who become the magnetic centres of movement, change, and accomplishment.

The adage is as old as the hills: if no one follows you, you are not really a leader. The problem is that most people who call themselves leaders do not really know if anyone is following them. They are too busy trying to create alignment — something about getting the right people on the right seats on the right bus. You can invest so much energy into managing, motivating, and manipulating the people circle in the name of “leadership” that the actual task itself is forgotten in the pile of self-help books.

“Leadership” has become more of a psycho-persuasion exercise than doing an action that other people repeat, mimic and respond to in turn.

Doers. As an alternative to general push, pull, and insider models of leadership, I want to suggest a third idea: go and do it and see who follows you. To really test your leadership capacity, quit trying to lead people and actually try doing “the thing” you want others to do. If people come along then you have followers — then and only then are you truly a leader.

The first concern of the leader is the goal circle, not the people circle. Yes, you should care deeply and genuinely for your followers — caring for those around you is indispensable — but don’t confuse your “followers” with people who you are merely trying to coerce into doing something that they would never find you yourself doing.

Leadership, as a methodology, sells a lot of books.
Leadership, as a job title, is an institutional invention.
Leadership, as a discipline, is the pathway to dogmatism.
Leadership, as an ideal, is the instigator of disillusionment.
Leadership, as a status symbol, breeds resentment.
Leadership, in a reality, will simply change your neighbourhood.

Peering through the veil of "It's for your protection".

2013-06-07T06:22:00.000-07:00

Recently our government has been collecting data on ALL phone traffic from Verizon. Today it was revealed that they were actually collecting data from 9 different internet companies including Google, Facebook and Twitter. U.S. mining data from 9 leading Internet firms This program apparently costs 20 mill a year to run. When you think about it, it's pretty amazing ... all this coordination and only 20 mill a year and it's all for our protection. If this were true, then the people charged with protecting us should should be truly treated like heroes ... right?

Of course not, because this isn't about protecting americans. This is about power plain and simple. Think of how much power the IRS will wield the next time it wants to attack opposing political parties. Or how much power the DOJ will wield the next time it needs to track down the source of a leak.

We should be ashamed that we allow this to continue. While at the same time make the men and women out on the battlefield giving their lives for our so called freedom wait on average ONE YEAR to provide the benefits they so desperately need. Average Wait times for Veterans Administration Services!

Unprotect PDFwith password

2013-02-01T15:32:00.000-08:00

I continually receive PDF's from either my accountant or my bank that are password protected which means if I want to extract a page or two and then fax to a bank to verify funds for a purchase, the print to PDF option won't work. So I have done this a few times now and wanted to document for others and myself since I keep forgetting how to do it.


gs \
  -sPDFPassword=pass \
  -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite \
  -sOutputFile=unencrypted.pdf \
  -f password_protected.pdf

This will open the file using GhostScript and then create a new file and the new file will not be protected. The important part here is the first param giving the password to gs.

Brute force using VIM

2012-06-21T08:05:00.001-07:00

I was just presented with a situation where about 60 html files were generated and some of them contained duplicate entries that needed to be removed. We couldn't go back and re-generate because some of the verbiage on the pages had been tweaked already. I started looking into sed to see if it would help, but it apparently doesn't shine at finding duplicates and removing them. So it looked like the only way was to brute force edit each page ... blah!

But wait ... VIM can make even the most laborious task seem trivial if you know a few key concepts.

So I decided to buffer all the *.html files and tell vim to find a specific string in each of them. The string was the html class of the menu.

vim +/search\ string *.html

Now I have all the files open and I simply need to review each one for the dupes. So for each file, I simply pressed "n" to find the next occurrence. If the dupe was present, I executed

7j+shift+v6jd

move down 7 lines, start selection, move down 6 lines then delete the selection. Then I simply saved the file and deleted it from the buffer and on to next file.

I probably could have used a macro but that would have taken longer to learn than the 10 minutes it took to edit the files. So I'll put that at the top of my reading list.

Knowing your toolset can make the most laborious task seem trivial. Continuous learning, not just the language you use but the tools that support your efforts, is the key here.

Great UX design postings

2012-05-06T05:41:00.002-07:00

Things to keep in mind when designing UX.

http://bokardo.com/principles-of-user-interface-design/

and

http://uxdesign.smashingmagazine.com/2012/04/26/gamification-ux-users-win-lose/

Love some of the gamification concepts.

Accessing command line from within VIM

2012-05-03T11:38:00.000-07:00

This has proven pretty handy and wanted to document so I wouldn't forget.

To suspend VIM and reveal the current command line:

"Ctrl+Z" then run your commands as normal and then "fg" to return to VIM.

This will also execute the command and wait for you to hit enter before proceeding:

":!"

Faster Terminal Logins

2012-04-26T12:39:00.001-07:00

That slowness when you start Terminal? It's parsing through all your system logs to figure out when the last log-in occured. Speed up your terminal with

touch ~/.hushlogin

From: http://pivotallabs.com/users/onsi/blog/articles/2088--sf-standup-4-26-2012-hush-terminal-hush

Using tmux

2012-02-26T06:29:00.002-08:00

Just started using GNU Screen recently and it's definitely a productivity booster. Saw a post comparing screen and tmux today and now I think tmux might be the way to go. Screen doesn't appear to be under active development and tmux has a few features screen lacks (vertical split) ... anyway here are a couple of articles I found helpful during the switch.

http://www.dayid.org/os/notes/tm.html

http://www.linuxized.com/2010/05/switching-from-gnu-screen-to-tmux/

Real leaders follow through on their promises ...

2012-01-24T06:13:00.000-08:00

Very few times in history have leaders actually followed through on what they promised. Government Transparency was one of those promises and this simple serves to hide what our elected officials are actually doing. This generally leads to disenfranchised voters that simply ignore the process in future elections. I will vote in the next election and I will vote for Ron Paul ... even if I have to write his name on the ballot myself.

Read the following article from Salon ...

Rules of American justice: a tale of three cases

As EFF’s Trevor Timm put it yesterday: this is the “6th time under Obama someone is charged with Espionage for leaking to a journalist. Before Obama: only 3 cases in history.” This is all accomplished by characterizing disclosures in American newspapers about America’s wrongdoing as “aiding the enemy” (the alleged enemy being informed is Al Qaeda, but the actual concern is that the American people learn what their government is doing). As The New York Times‘ Charlie Savage wrote this morning, Obama has brought “more such cases than all previous presidents combined,” and by doing so, has won the admiration of the CIA and other intelligence agencies which, above all else, loathe transparency (which happens to be the value that Obama vowed to provide more of than any President in history).

Rails 3 with SQLServer 2000

2011-02-01T15:12:00.000-08:00

I've been working on a new front-end to our legacy system and was disappointed to find that ActiveRecord 3 would not support SQLServer 2000 due to some limitations with the Arel gem. So after trying without much success to find a patch that would make this work, I wrote my own.

One big change is that the table reference for :set_table_name is now case sensitive. I don't believe it was in the past. So either make sure those names match or you will see cryptic messages like:

NoMethodError: undefined method 'eq' for nil:NilClass (yeah that was fun to track down)

There are a couple of other basic changes that need to happen so make it work at all. You need to change the SUPPORTED_VERSIONS constant and also change the TOP definition in the Arel SQLServer Visitor ...


module ActiveRecord
  module ConnectionAdapters
    class SQLServerAdapter
      SUPPORTED_VERSIONS          = [2000,2005,2008].freeze
    end
  end
end

module Arel
  module Nodes 
    module Visitors
      class SQLServer
        def visit_Arel_Nodes_Limit(o) 
          "TOP #{visit o.expr}"
        end
      end
    end
  end
end

This will get the basics to work. You still won't be able to use some of the advanced features like offsets without further modification but this did the job for us. Well almost, there were a few other changes that needed to be made in our case since our column names are mixed-case. If you would like more info on these, let me know in the comments.

All the code here is found within the activerecord-sqlserver-adapter gem. I created overrides for all the methods and placed them inside the Rails app so that gem updates wouldn't cause any issues.

Of Labels and Limits

2009-05-27T12:59:00.001-07:00

Saw this come across my feedreader today and it resonated on so many levels.

================================================
Original Blog Post::: Of Labels and Limits
================================================
In an attempt to satisfy our need for identity and belonging, we desperately try to wear as many labels as possible, and to a certain extent labels are a necessity. When people ask you what you do for a living, it’s far easier to reply “I’m a computer programmer” than to try and explain the plurality and complexity of the exact criteria of your job.

The problem with labels is that they can place you in a box, at times greatly limiting who and what you are. So while it’s okay to use labels to efficiently communicate with other people, it’s important not to fall into the trap of taking them too seriously, thus letting them become who you are - or are not.

It’s not the label per se, but rather our perception of what our identification with a given role implies. If I identify myself too strongly as a “rubyist” I may not be inclined to recognize the good that is found elsewhere in other programming languages, or worse still, reject such good in an attempt to defend the choice I opted to identify myself with. This inclination is the basis of many of the “religious wars” you see online.

I sometimes find myself in the odd predicament of limiting myself because of some label or assumption of what “a person like me” can and cannot do. In such instances though I’m reminded of a few stories about courageous individuals who went beyond labels, above the layer of conventionality, breaking what common sense would have considered a “difficult to challenge” limit. I’m reminded of blind people who took on photography and managed to be successful at it, or of a black kid of Kenyan origins who managed to become the President of the United States of America. But there is one story in particular that always gets me, it’s the story of Django Reinhardt, after whom the the popular Python framework was named.

Django was a Gypsy jazz guitarist who was severely injured in a fire when he was eighteen. As a result of this accident his right leg was paralyzed and the third and fourth fingers on his left hand were severely burned. Doctors recommended amputating his leg and were pretty darn sure that he would never play guitar again due to the extensive damage to his hand. Django refused the amputation though and left the hospital as soon as he could. Within a year he was able to walk again, albeit with the aid of a cane. Even more surprisingly, despite being “disabled” in his left hand, he persisted through the pain to practice his beloved instrument. He went on to reinvent the conventional approach to guitar playing by performing solos with the use of only two fingers, using his half-paralyzed fingers for chord work. Today Django is considered one of the most influential guitarists of the 20th century.

I’ve learned to consciously fight the urge to limit myself. Whatever labels you feel may be cutting your potential short or holding you back, I encourage you to break free and rise above them. Does doing so mean you’ll reinvent the way a musical instrument is played, reshape the course of history or become a hero in your field? Perhaps, but even if it doesn’t, your own life stands to become richer and freer because you decided not to live within the confines of a label.
=================================================

Powering Nanorobots

2009-05-19T09:26:00.001-07:00

Imagine that we could make cars, aircraft and submarines as small as bacteria or molecules. Microscopic robotic surgeons, injected in the body, could locate and neutralize the causes of disease—for example, the plaque inside arteries or the protein deposits that may cause Alzheimer’s disease. And nanomachines—robots having features and components at the nanometer scale—could penetrate the steel beams of bridges or the wings of airplanes, fixing invisible cracks before they propagate and cause catastrophic failures.

This is a fascinating read.

How to Build Nanotech Motors

Nanotech has implications in everything we do from healthcare to sports. It is the next great frontier. I believe healthcare will see the most dramatic improvements. One of the problems we face today with the treatment of cancer is that the tools we have are too large to attack on only the cancerous cells and therefore we lose a lot of healthy cells in the process. Nanotech will be able to remove only the infected cells and work at much faster speeds.

Behavior

2009-05-06T16:16:00.001-07:00

Social Architecture ... very interesting article especially the thought that behavior is a function of a person and his environment: B=f(P,E)

Rise of the Phoenix

2009-04-04T06:01:00.001-07:00

Originally purchased in 2005, this 1968 Convertible Camaro has been a side project and been a little neglected of late. I finally pulled her out of the garage on Thursday April 2 2009 and sent her of the plastic surgeon. I already completed some of the restoration by removing and restoring the drivers side floor and rocker panels but quite a bit more needs to be done and I would rather drive the car this year than wait to find the time it needs to complete.

So, I'll post pictures of the progress and keep a running dialogue here.

Thanks for following along:

Direct link to Flickr photoset

Cleaning the Air

2009-04-03T14:34:00.001-07:00

Am planning on trying this in my bedroom. Reduces respiratory problems by 34% so it couldn't be all bad ...

Main Stream Media

2009-03-25T05:15:00.000-07:00

It occurred to me recently that the main stream media tends to focus on issues they think the public will understand or comprehend. I guess the whole AIG uproar got my mental juices flowing. I totally disagree with the bonuses that were paid, but do they warrant the outrage that ensued? I don't think so.

So why does the media focus so intently on this issue? Do they not think they have enough time to educate or inform us just a little more so we can make informed decisions. Do they think we don't care? Do they think -- possibly -- that we're not sharp enough to follow? Probably a little of each.

The amount of money injected into the financial system in recent history is staggering. I have seen numbers ranging from 3 to 7 trillion dollars. I'm not even sure how many zero's I need to make the numbers work. AIG alone received 170 billion. Mind boggling numbers. So the bonuses paid represent about one tenth of one percent of the total. So why all the outrage?

There are far more egregious uses of the money than these bonuses (see USNEWS - Why Did AIG's Counterparties Get 100% Repayment?). I'm thinking the reason this has not received any airtime -- at least that I've seen -- is that I can barely understand what it means so the media would have to educate or inform me a little more. But there isn't time for that when we need to hear about the Presidents dog choice or Condoleeza Rice's favorite band or the whole Rihanna/Chris Brown train wreck.

So back to the issue. Both the media and Congress jump on the populist bandwagon and ride it until the wheels come off. The effect of this is that the populist outrage gets louder and the cycle continues until no one knows how it all got started or what it was all about. This results in additional advertising revenue or getting re-elected to congress but it really doesn't help solve the problems we are facing today.

So stop paying attention to the talking heads and find a good blog or magazine -- the Economist tends to inform on global issues without injecting any political rhetoric into the mix -- and maybe we can stop focusing on things that simply do not matter when dealing with problems of this scale and put an end to this disaster.

Another Good One ...

2009-03-04T20:06:00.001-08:00

I posted this to a previous blog and wanted to make sure I had it around for future reference.

Ray Kurzweil

Accelerating Change 2005

2009-03-04T19:55:00.001-08:00

I listened to this session on the way to work this morning. The speaker talks about exponential change and what could happen in the future if Moores Law continues to hold. He discounts the fact that most people find the ability to re-create human intelligence interesting. We can do this today ... and it only takes 9 months. What he does find interesting is the point after we re-create intelligence in the form of a computer. So the computer in one generation would have intelligence equal to human then the next transition would be super-human and so on ...

Here's the link to the podcast.

Vernor Vinge - Accelerating Change 2005

Asimov

2009-03-04T19:45:00.001-08:00

awesome mix ...

2009-03-04T13:19:00.001-08:00

Courtesy of Ze Frank

Thru-You

Pretty cool mixup of various videos from youtube.

Interact first, sell second!

2009-02-27T15:39:00.001-08:00

The panhandler's secret

from Seth's Blog by Seth Godin

When there were old-school parking meters in New York, quarters were precious.

One day, I'm walking down the street and a guy comes up to me and says, "Do you have a dollar for four quarters?" He held out his hand with four quarters in it.

Curious, I engaged with him. I took out a dollar bill and took the four quarters.

Then he turned to me and said, "can you spare a quarter?"

What a fascinating interaction.

First, he engaged me. A fair trade, one that perhaps even benefited me, not him.

Now, we have a relationship. Now, he knows I have a quarter (in my hand, even). So his next request is much more difficult to turn down. If he had just walked up to me and said, "can you spare a quarter," he would have been invisible.

Too often, we close the sale before we even open it.

Interact first, sell second.