Accidental Technologist

Musings about Entrepreneurship, Technology and Software Development

Overcoming the Mimemagic Fiasco

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I’m sure if you are a Ruby on Rails developer, you have heard about the fiasco that is Mimemagic.

It seems a component used in the Mimemagic gem was under a GPL license which was different than Mimemagic but because of how these licenses work, trickles down to users of Mimemagic. In this case the Ruby on Rails gem. If you’re interested in some of the background, the Ruby on Rails issue, Dependency on mimemagic 0.3.x no longer valid #41750, can fill you in.

The gem was yanked from Rubygems and because of this, the gem could no longer be installed so builds broke everywhere. Users received the message:

Your bundle is locked to mimemagic (0.3.5), but that version could not be found
in any of the sources listed in your Gemfile. If you haven’t changed sources,
that means the author of mimemagic (0.3.5) has removed it. You’ll need to update
your bundle to a version other than mimemagic (0.3.5) that hasn’t been removed
in order to install.

I have several clients needing a way to resolve this problem.

I came up with a couple different options.

Option 1 – Remove Dependency

After a bit of research I discovered that Mimemgic was used by the Marcel gem which is required by ActiveStorage. If the application did not use ActiveStorage then removing the dependency would solve the problem. If you use ActiveStorage, this is not an option.

Implementing this is pretty straightforward. Opening up your config/application.rb, you should see where Rails is required:

require "rails/all"

Instead of requiring all, just require what you need and remove the ActiveStorage dependency. This is what requiring rails/all includes:

active_record/railtie
active_storage/engine
action_controller/railtie
action_view/railtie
action_mailer/railtie
active_job/railtie
action_cable/engine
action_mailbox/engine
action_text/engine
rails/test_unit/railtie
sprockets/railtie

Just remove the second line and require each of these individually and you will be all set.

Option 2 – Change how the gem is included

Since the Mimemagic gem is open source and the code is in a git repo, we can identify the commit created when version 0.3.5 of the gem was released. Some commits that should solve the problem:

My projects have been using v0.3.5, I found the commit and added this to my Gemfile:

gem 'mimemagic', '0.3.5', git: 'https://github.com/mimemagicrb/mimemagic', ref: '01f92d8'

This is a short-term fix. I expect once the Rails team resolves the dependency, new versions of Rails will be released.

Redis::CommandError – MISCONF Redis is configured to save RDB snapshots

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I recently ran into a problem I hadn’t encountered before on my Mac. I was getting an error from Redis:

MISCONF Redis is configured to save RDB snapshots, but it is currently not able to persist on disk. Commands that may modify the data set are disabled, because this instance is configured to report errors during writes if RDB snapshotting fails (stop-writes-on-bgsave-error option). Please check the Redis logs for details about the RDB error.

The fix is simple. From a terminal window, enter the Redis CLI. From a terminal window type:

redis-cli

Use the command:

config set stop-writes-on-bgsave-error no

You should get an OK response, then type exit to get out of the reds-cli.

Try again where you received the error and everything should be working as expected.

frozen_string_literal: the not so magical comment

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I have been working on a project over the past year for a client with a large Ruby on Rails application. The project has allowed me to learn more about how large Rails applications are developed and managed in the real-world. I’ve picked up some real gems to help scale Rails applications which I’ve used in some of the smaller applications I maintain.

One of the gems I learned about was the use of this magic comment:

# frozen_string_literal: true

This comment was added to every Ruby file in this company’s application, which included several microservices along with a large main application. The files numbered over 1,000.

I read up on the use of this magic comment use in other projects and the results seen. One in particular was Sidekiq from Mike Perham. Mike documented his use of the magic comment and how it improved his use and helped cleanup his code.

Ruby 2.3 introduced a very nice option: each Ruby file can opt into Strings as immutable, meaning all Strings within that file will automatically freeze, with a simple magic comment at the top of the file.

Mike includes some benchmarks that show improved memory footprint for Sidekiq. This was enough for me.

I had one relatively small application that had an API component I was optimizing (Rails 5.2.x and Ruby 2.6.6). I thought about the use of the magic comment and decided to give it a try. I added it to every Ruby file in the project and was included as part of the weekly deploy.

The deploy was done after hours one evening and I was ready to witness the magic.

Unfortunately, this magic did not happen. I noticed right away the response times of API calls were slower, not faster. Maybe I was seeing the effects of cold cache calls and things would improve overnight.

The next morning in fired up Skylight to check the response times from the API. To my surprise, the response times did not improve. Since the only change in this deploy was the use of magic comments, I decided to rollback the changes. This application runs on Heroku, rolling back with really easy and does not require reverting the code back and redeploying.

The result was noticed instantly:

IMG 1186

Response times drastically improved as you can see from the above graph.

At this point, I don’t have any reason to believe it’s not the magic comment that caused these longer response times.

During my brief research about the comment’s use, thinking there was more to using it than simply using it everywhere, I ran across a thread from the Ruby lang issue list. The threads title, Reconsider impact of frozen_string_literal on dynamic strings, I found interesting. Maybe this is a clue and dynamic strings being frozen in my application is part of the problem.

It sounds like there is a benefit to use this feature but not everywhere, the exact result I saw in performance graphs.

I am still exploring when to use the magic comment and when it shouldn’t be used. If you are using this throughout your applications it might be worth measuring with and without their use. Any others have more information to share, please reach out.

Status Bar in iTerm2

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I’m a big fan of iTerm2. I’ve used it since it’s inception and haven’t looked back. Even after all of this time I still discover features I didn’t know existed, mainly because I wasn’t looking for them.

I recently discovered you can have a status bar at the top of the terminal window with various stats and data points. My status bar is simple at the moment; containing system CPU usage, memory usage and disk throughput.

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How did you do that?

Adding the status bar is pretty simple. Go to iTerm2 -> Profiles -> Session:

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Check the box for Status bar enabled and then configure the status bar by clicking the Configure Status Bar button.

There are a bunch of options here so I think it’s worth playing around with how the terminal looks. There is even an option to run a script, which opens up many possibilities. Simply drag-and-drop the component you want to have in your status bar. Select a component you made active and you can customize it by the Configure Component button.

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If anyone sets this up and adds calls to scripts, I’d love to hear how you use this feature or how you get creative with other features.

Supporting Multiple SSH Keys on macOS

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If you’re a developer, on devops or a system admin you probably use an SSH key to log into remote servers.

I am typically on multiple projects at one time and some organizations require I generate a unique SSH key in order to work with them. I’ve been fortunate until recently that my personal SSH key was acceptable.

So, how can you have two or more SSH keys available on your system at any one time? I am running a Mac but I assume this would work on Linux as well.

It’s not hard and when setup, it works really well.

Getting Started

The first part is generate a new SSH key. Understand that the email you’re using here may be an email provided by you client or company. It may not be the email you normally use.

ssh-keygen -t rsa -b 4096 -C "[email protected]"

There are a few different types of keys you can generate. If you’re interested, GitHub has some good help with SSH keys.

Generating public/private rsa key pair.
Enter file in which to save the key (/Users/rbazinet/.ssh/id_rsa): example_com_id_rsa

I use something specific to the company for who I’m adding the key. You can see here the new SSH key is example_com_id_rsa. Please be careful here, if you leave the default you may overwrite your existing key. You probably don’t want to do that.

The Key is the Config

Head on over to where your SSH keys are stored, probably in ~/.ssh directory. Edit the config file, simple called config. It probably looks like mine:

Host *
AddKeysToAgent yes
UseKeychain yes
IdentityFile ~/.ssh/id_rsa

Add your additional host. I added mine above the original.

Host git.example.com
Preferredauthentications publickey
IdentityFile ~/.ssh/example_com_id_rsa
Host *
AddKeysToAgent yes
UseKeychain yes
IdentityFile ~/.ssh/id_rsa

The host is the system you need access to. It could be a git server or some other resource. Wildcards work here so if you need to access all resources on s particular domain, you would handle that here. There are a lot of things you can do in the config file and way you do them varies in complexity. If you want a more detailed explanation, Digital Ocean has a good resource.

I hope this helps.

Using the Microsoft Ergonomic Keyboard on macOS

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IMG 6167

I’ve been through a fair number of keyboards over the years, some expensive and some not. One of my favorites is still the CODE Keyboard, which I wrote about before. I still love this keyboard but I was starting to have pain in my forearms after a long day of typing. I keep coming back to the Microsoft Ergonomic Keyboard to on macOS. Why? Because it’s a tradeoff between being ergonomic and being inexpensive. I’ve seen some other customizable keyboards in the range of $350 but I haven’t found the large price tag necessary.

One annoyance when using many keyboards is the fact that they are setup for Windows operation system and not macOS. This means the Command key is not to the left of the space bar as Mac people expect. The Microsoft Ergonomic keyboard has the Alt key in that location. It’s a simple fix.

Go to System Preferences -> Keyboard -> Modifier Keys…

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Notice the Option Key and Command Key defaults. The Mac is recognizing the Alt key as the Option key. We need to make a change.

MicrosoftKeyboard Before

The easy fix is to swap the two keys in the modifier. Option becomes Command and Command switches to Option. Click OK and everything should work as expected.

MicrosoftKeyboard After

This saved the day with properly mapping the command key. If you need other keys mapped differently on this keyboard, there is another option. Karabiner is a powerful utility for the Mac that allows a wide variety of keyboard mapping. It was more than I needed.

I hope this helps.

10 Steps to Survive Working from Home

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10 Steps to Survive Working from Home

I’ve been working from home for the past 16 years and love it. I wouldn’t have it any other way. Surviving working from home when you’ve never done it, can be challenging.

Working from home isn’t for everyone and takes discipline.

I thought with all the people recently forced to work from home due to COVID-19, I’d share some tips that have helped me over the years.

  1. Find a dedicated space. Even if it’s temporary, have a place you go to in your home. If all you have is a bedroom then try to create the environment there, a small table near a window would work well. If you have a dining room or kitchen to use, then set up on a table in there. You may need to move at the end of the day for dinner if you don’t live alone. Sitting on the couch in the living room with the TV on probably isn’t going to work.
  2. If you have a family with young children home, try to set boundaries. Let others know you are home to work, and there will be time after your day is done for time to be part of the family. If it’s hard to have quiet time, get a pair of noise-canceling headphones. I use Bose QC-35’s and love them. Unfortunately, they are not cheap.
  3. Get up and do the same routine you’d do if going into the office. If you get up at 6:00 am, shower and get dressed. If you have an hour commute, then use that time to listen to a podcast, audiobook, or catch-up on the news. Start work at the same time.
  4. If you’re used to a busy office, have the radio on or TV in another room to provide some background noise. Silence can be hard to deal with, and adding some level of noise can help. I like quiet when I’m deep in work but like background sound otherwise.
  5. Stay in touch with coworkers via Slack, Zoom, or other means. Brief video calls with Zoom during the day can help you feel connected. This one is probably one of the most important. It can be lonely working from home, and you have to figure out how to fill the void.
  6. Leave your desk for lunch, even to the living room or deck. It would help if you got away from your computer.
  7. Take plenty of breaks. It’s essential to get away from the computer, so get up and get some water (yes, drink plenty) or set outside.
  8. Eat as you do at work, don’t indulge because the food is close. Too much food can make you feel lethargic and lead to unnecessary weight gain.
  9. End your day by making some notes about what you plan to work on the next workday. This way, you get to your computer and have a plan to get your day started. I’ve gotten into this habit; it reminds me of what I was working on and where I need to start for the day.
  10. Stop working the same time you usually do, don’t feel like you should be working more because you’re home.

I hope this helps.

Remember, it’s only temporary. Maybe this new lifestyle will suit you, and you will want to work from home more.

Photo by Thought Catalog on Unsplash

“Are you building a business or learning a stack?”

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Stefan cosma 0gO3 b 5m80 unsplash

I always love when someone posts something online saying they have an idea for an application and ask, “What stack should I use?”

It’s a fair question, but the answers usually start with “it depends”.

What is a “stack”?

The “stack”, for those unfamiliar with the term, refers to what programming language, frameworks, and database a project uses to get its work done.

Examples could be Ruby, Ruby on Rails and PostgreSQL, or JavaScript, NodeJS and MongoDB or maybe C#, ASP.NET Core, and SQL Server. All acceptable choices to build a web application.

Indie Hackers

There is a post on Indie Hackers, titled Tech Stack Suggestions. The original poster wants to build an MVP for his business idea and is soliciting opinions as to what stack to use.

He’s wondering about using a frontend framework like React and replies to someone suggesting he keep it simple:

Shouldn’t I be using a frontend framework in order to develop this? Backend Django + SQL has its advantages, in fact, the current project I’m working on in my organization is partially based on that. But, I’d like to implement things like GraphQL, NoSQL primarily to get a more hands-on on how they’d work in a real project. Would really appreciate your input.

Volkan Kaya replies with brilliant and practical advice:

Are you building a business or learning a stack?
If you want to learn a stack do it while being paid, not while starting a business.

Nick Haskins pragmatically suggests:

It’s really unfortunate that our industry has convinced you that you need to utilize tooling built for larger applications. On behalf of the industry, I apologize for that.
You do not need a front-end framework to develop a web app.
I’ve built multiple very large apps with Rails + Bootstrap. No ReactJS. No VueJS. No JS libs, just a sprinkle of jQuery.

These are examples of excellent and practical advice. The responses to the post include a lot of misguided answers as well.

Shiny Things

The thread from Indie Hackers sums up what it’s like to be a technologist who wants to build their software. You should give the thread a read.

It’s easy to want to build something and want to use the latest frameworks. It’s a great chance to learn something new. I’m all for learning; you should never stop. But, if your goal is to build a business and challenge yourself with new technology while doing it is not the best decision.

I’ve been guilty of trying to convince myself there’s some technology I need to use because applications that are created with it are faster or scale better. It’s not essential before you have that problem. People will try to justify using it anyway.

Don’t follow like sheep do…right off a cliff.

Love the One You’re With

It’s best to take a step back and breathe. Take stock in yourself and where your strengths lie. Ask yourself which programming language and framework you use most today? Which one do you make a living using today?

What is wrong with this combination that you wouldn’t want to use it to create your application? You want to make the right choice and not regret it later.

In its most basic form, people want to make an application and try to think too far ahead. Thoughts of scaling, finding developers, performance, and such things that don’t matter until later.

As a software entrepreneur, more appropriate questions you should be asking yourself are:

  • Am I solving a real problem?
  • Do I know people who will pay me money for my solution?

These are the questions to ask yourself now. Notice these have nothing to do with the stack you choose.

The simple answer to the stack question as a developer is to use the stack, you know, leading from idea to product in the shortest amount of time.

Why strap yourself with two hard problems? Toss the stack problem right out the window.

The best advice is to use the framework you are most comfortable with and will be the most efficient—the one you can get done what you want in the shortest amount of time. You’ll be happier and have something to show for it.

Don’t let people try to convince you their stack choice is better. They will have convincing arguments. None should sway you.

Exceptions

The above is my rule, but there can be exceptions.

As a Ruby on Rails developer, if I want to build a native Mac application, then I probably need to use Swift or Objective-C. Yes, I could use something like React Native; that’s not the point, so please don’t send me an email to the effect. If I don’t know the language, then I have given myself multiple challenges.

I’m sure there are other instances where I would need to learn something new, but the cases will be unusual when you’re deciding the application to build.

Conclusion

If you’re planning on starting a software business and you’re going to be the primary developer, then use the tools you know best. You are in a great position to get something out for your customers to see. Remember, they don’t care what your application is written in, only that it solves their problems.

Switching to Fathom Analytics

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Fathom analytics

I’ve used Google Analytics for many years, and continuing because it’s free. As time has gone on, I’ve decided to use Google products less and less.

Google Analytics always seemed to be complicated or maybe overly complex for the pieces of data for which I care. It gives many details I have never used.

Enter Fathom

I started looking for an alternative analytics tool. I discovered Fathom. Fathom offers excellent features and the ones I care about most. I like to be able to see:

  • What are people reading?
  • Where are they coming from?
  • What is the visitor’s geographic origination?
  • What browser are visitors using?

I did a quick informal survey of analytics tools on Twitter that resulted in a favorable response for Fathom. They offer a 7-day trial.

  • Fathom allows unlimited sites
  • Privacy – they don’t collect personal data
  • Great support, yes, I know first hand. Quick, helpful replies.
  • Pricing is by total page views over all your sites.

Installation

Installation is simple, add a JavaScript snippet to each page or template to start tracking. If you use WordPress, there is a handy plugin that adds the Fathom Dashboard to WordPress. One issue I had was getting the analytics dashboard to show up in WordPress and making sure sharing is enabled. You need to tell Fathom to share data with WordPress because it’s an external site.

Notice the setting, the default being Viewable by You. Change the setting to Viewable to anyone with the share password.

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If you ignore this setting, you won’t see analytics in the WordPress Dashboard, only a 404 error.

Support

I contacted Fathom support a couple of times, and they were quick to reply from both Twitter and email. A couple features were missing, and support informed me of their full pipeline where features are always being added.

After using Fathom for the past few of weeks, it’s a great solution, and happy I made the change. I purchased an annual plan. Glad to support an indie developer.

If you’d like to check out Fathom and help me out, use my referral link. 🙂

How to Assign Static IP Address on Raspberry Pi

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I have been setting up a Raspberry Pi 3 Model B to use as a Pi-hole server to help block the constant wave of ads my family and I keep seeing on the Internet.

One requirement for Pi-hole is the host Raspberry Pi needs to be configured to use a static IP address.

The Problem

I’ve been configuring and administering Linux servers from the command line for years, but the task of setting up a Raspberry Pi to use a static IP address was a lot more complicated than it should have been.

I started with the Raspbian GUI, expecting a Network Settings dialog where I could make the necessary changes. No such luck.

On to the obligatory Google search to find some instructions on the process. Many people are asking the same question.

Surprisingly, there are very few answers, and even less that worked. A total of 0 worked for me on my Raspberry Pi 3 Model B.

The Solution

After much trial and error, I discovered a combination that works. I wanted to write this up for a couple of reasons; first, to help others that have better things to do with their time and second, a reference I can go back to when I forget how I solved this problem.

It comes down to modifying a couple of files and adding a small bit of configuration.

The first file to update is /etc/dhcpcd.conf:

sudo nano /etc/dhcpcd.conf

Most of what needs to be added already exists in the file commented out. I left the file as-is and added the changes to the bottom of the file.

The first line indicates which interface (network card) I’m configuring, the wired port, if you’re on WiFi use wlan0 instead of eth0 for the interface.

Lines 2-4 should be pretty clear, set the IP addresses specific to your network. Line 4 indicates I am using Cloudflare DNS servers.

Line 5 sets up the static IP address even with no network cable attached. Probably not necessary but I wanted it in there.

interface eth0
static ip_address=192.168.1.200/24
static routers=192.168.1.1
static domain_name_servers=1.1.1.1 1.0.0.1
nolink

Don’t forget to save your changes, Ctrl-x, then select Y and then press Enter to keep the file name.

The second file to update is /etc/network/interfaces:

sudo nano /etc/network/interfaces

I added this to the bottom of the file.

interface eth0 manual

This line means the interface is configured manually and does not use DHCP.

Again, don’t forget to save your changes, Ctrl-x, then select Y and then press Enter to keep the file name.

Restart the DHCP daemon or reboot.

sudo service dhcpcd restart
sudo reboot

Finally

After much trial and error and the static IP address set, configuring the Pi-hole is easy and works great.

I’m currently blocking ads at a feverish pace.