Episode V – The Last DevOps

This is the last part of a DevOps related topics series:

I’ll be talking about the previous blogposts, if you want to read them here they are:

• Episode I – What is DevOps?
• Episode II – DevOps Strikes Back (Linux and crons)
• Episode III – Return of DevOps (SHH and Git)
• Episode IV – JUnit Awakens (JUnit and node js)

Bring balance to DevOps culture, image from this medium post

So… DevOps?

Though the 3 previous parts, we practiced our Continuos Integration. We built and test (and did some kind of monitoring) to a central repository after “automated” builds tests are run.

“Continuous Integration doesn’t get rid of bugs, but it does make them dramatically easier to find and remove.”

Martin Fowler, another guru of software as Kent Beck

So I learned that DevOps is helpful for finding errors quicker than waiting until the end. Sometimes you don’t know the failures that might happen outside the local environment.

• 

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The Goats

Cheating a bit with Jenkins

Jenkins is a good option if you want to build at a bigger scale. This is an open source automatization server written in Java, advantages of using it:

• Continuous integration an delivery
• “Easy” installation and configuration
• Has hundreds of plugins
• Extensible and Distributed.

I know that a lot of companies use Jenkins because it makes the DevOps practices a lot easier, since it has a lot of flexibility.

But not everything is color pink. One of its advantages can be a double edge sword, the fact that is OpenSource. Therefore some issues might take longer to fix. Also the migration from an old instance to the newest is a big pain (real work-life situation).

Excise Task

By this day, I had this question twice in my Testing course exam, “What’s the deal with excise tasks?”

Excise is all the extra stuff we have to do, what it costs, or the time spent on the project. For example, buying licenses, researching, money used on testing. These tasks consume a lot of our time. I believe this is natural, that excise tasks take more time that actual revenue.

Off topic – Exam week

This post won’t have the minimum quality I would expect for my regular blogposts. But what would you expect from a post I’m writing a Friday Night/Saturday morning at 1:20am?

Taken from neatoday

I just finished all my hard exams and started to felt weird for doing nothing, so writing a post for this blog was a partial terrible? solution. I’m 100% sure this will change tomorrow morning after waking up for the first time in 6 days of sleeping ULTRA late. I didn’t left things until the end this time, but the fact that I’m a graduate candidate makes everything worse. It’s like being the guy who will kick the last penalty in a final of the FIFA world cup. A mistake can decide of whether I graduate or not.

Image taken from here

CENEVAL exam, student loans documentation, and exams week merge into a short period of time. But I have faced this kind of stress at least once every single semester during the 5 years of college and every time I have survive. I thank all my friends and family that have supported me to become the person I’m today. A person who can write a blogpost of DevOps and only speak about it for 1/3 part.

I learn basics of DevOps and realized that 90% of the time doing the code was trying to figure out why it didn’t work, therefore it was excise.

Don’t you know it’s gonna be alright?

The Beatles -Revolution

Episode IV – JUnit Awakens

Welcome back to a series of blogposts about how to set up a little server in a Linux Virtual Machine, in this post we will lean JUnit and status

if you are not familiar to the topic you can go to the first, second or third part of the series

JUnit via command line

Set up (again?)

First be sure you have Java in the machine (We did this in the last part)

Lovely Ubuntu LTS Interface

Be sure you can compile Java files

I created a class so we can see everything is working fine

Download Junit archive

Download latest version of JUnit jar file from http://www.junit.org, the easiest way in Ubuntu TLS is the wget command. (link in image description)

https://github.com/downloads/junit-team/junit/junit-4.10.jar

So type: wget https://github.com/downloads/junit-team/junit/junit-4.10.jar

Create actual tests

My Hello class was pretty much useless. So I take the example from the JUnit Team. And I created two files (these are literally copy-pasted from their repo: https://github.com/junit-team/junit4

You can find this code also at my repo https://github.com/kevintroko/JUnitTest/blob/master/Calculator.java

You can find this code also at my repo https://github.com/kevintroko/JUnitTest/blob/master/CalculatorTest.java

Compile!

We have to do the command javac -cp .:junit-4.XX.jar:hamcrest-core-1.3.jar Calc^CatorTest.java (remove the XX for your version)

In my case since I have the junit-4.10.jar, I put 10

Run the test

Enter the command:

java -cp .:junit-4.10.jar:hamcrest-core-1.3.jar org.junit.runner.JUnitCore CalculatorTest

Oh lala, JUnit is running at Ubuntu LTS!

Setup status page

It’s time to do some testing with our cron jobs. First I’ll power up my server.

Remember node command doesn’t exist in our environment, instead it’s nodejs.

So then I implemented a logger in my JUnit tes for the CalculatorTest.java, based on this post of stack overflow

Logger in my test

And I also created a file watcher in my serve so when it detects that my file with the error output it writes “Build” in my readme

npm install node-watch

So sadly it just change the file when it pass, but it doesn’t push it for some reason 😦

I had a very bad time with this easy example. So I don’t wanna know about the professional DevOps (DevOperators?)

Readme Test

How could you update the README page on your repository to reflect the build status using this setup?

PyCharm feat. WWW & SmallTalk

Happy Birthday Internet!

Last week was the 30th anniversary of the World Wide Web! 🎉 This is the same year that the Berlin wall came down and sadly the last time that Liverpool became premier league champions. (yes it’s a long time ago).

So thanks to Tim Berners-Lee, inventor of the WWW, now you can be reading this post from almost any part of the world (not the building 2 from Tecnológico de Monterrey, Campus GDL internet is really bad in there). Here is a quote of him that describe his vision of the internet

Suppose all the information stored on computers everywhere were linked. Suppose I could program my computer to create a space in which everything could be linked to everything.

Tim Berners-Lee

Internet has changed our life in sooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo many ways. And I’ll show some of them thanks to a very cool site that took ✌🏻screenshots✌🏻 of old web pages, this is WayBackMachine.

Its awesome to see how internet keeps changing. In 1994 (just 5 years after the WWW was created) Pizza hut was already doing online pizza delivery. The site (image below) looks like a site that didn’t found the css file. But still it’s awesome to see how we integrate the net into our daily life.

Image taken from WayBackMachine

Simple Smalltalk Testing

Changing the topic a little lot, I’ll speak about basic small talk. This is based on this article written by Ken Beck (a guru of testing).

I answer some of the questions because there were so many of them

If you want to see my thoughts about the article directly you can download the hypothesis chrome extension.

PyCharm and PyUnit

If you have Linkedin Learning (before Lynda) a good course you can follow is this. I couldn’t find any place to leave a comment but in a form of Course Evaluation, and I also gave a like to the course.

Py Test and PyCharm

For more learning you can go to https://docs.python.org/3/library/unittest.htmlYour evidence (again screenshots) of using PyCharm with pyunit.

Episode III – The Return of DevOps (SSH & Git)

Welcome back to a series of blogposts about how to set up a little server in a Linux Virtual Machine, in this post we will lean about Github and SSH

if you are not familiar to the topic you can go to the first or second part of the series

Ensure that you have your GitHub account.

Before you start you should have a Github account.

You can follow me @kevintroko (for some reason)

Ensure that you have a repository created for testing.

If you followed the last part we had a web server created in node, we will use this. This will be our root.

Setup your GitHub two-factor authentication.

This part is a step forward process and Github explain it 100 times better than me, but I’ll explain it anyways in case you don’t want to move to another site. It’s really nothing from the other world, is more just following a series of steps:

Go tho the git setting and click in the security tab

Click the enable two factor button

Follow the steps in the site

⚠️ ⚠️ DONT FORGET TO SAVE YOUR RECOVERY CODES ⚠️⚠️

They send you a mai anyways

You are ready

Github SSH keys Setup

This is a little bit harder than the last step, the Github team explain it as well (though some commands don’t work the same for ubuntu)

ssh-keygen -t rsa -b 4096 will create a SSH key with a 4096 encryption

ssh-keygen -t rsa -b 4096 -C “put your own email”

They will ask you for the passphrase

Enter your pass phrase from the last step

It will generate the next output

eval the ssh agent

The GitHub page recommend to get the RSA key like this, but ubuntu won’t recognize natively this command, you can just cat the file instead

Ensure that you can do a git clone (use ssh) to your server from your repository.

Clone the repo with ssh as ssh://git@github.com/<your username>/<repo name>.git

Node running

Be sure to create a token because then it will not allow you to push the new data

Chapter 6.1, 6.2

What two properties must be satisfied for an input domain to be properly partitioned? 

1. The partition must cover the entire domain (completeness)
2. The blocks must not overlap (disjoint)

What is an Input Domain Model (IDM)?

An input domain model (IDM) represents the input space of the system under test in an abstract way.

A test engineer describes the structure of the input domain in terms of input characteristics. The test engineer creates a partition for each characteristic. The partition is a set of blocks, each of which contains a set of values. From the perspective of that particular characteristic, all values in each block are considered equivalent.

What gives more tests, each choice coverage or pair-wise coverage?

An each case coverage requires one value from each block for each characteristic. A pair-wise coverage a value from each block for each characteristic to be combined with a value from each block for each other characteristic.

Hence, a pair-wise coverage gives more tests.

Episode II – DevOps Strikes Back

Welcome to a series of blogposts about how to set up a little server in a Linux Virtual Machine, if you are not familiar to the topic you can a little more about in here (which is the first part of the series)

Install a Linux distribution

For this task, I chose the Ubuntu 18.04.1 LTS which runs in Virtual Box. This is the same I use for other courses (maybe this is not a good idea). If you would like to download the same Linux distribution, you can install this “old” mini iso from ubuntu.

Lovely ubuntu running in my VM

Other Linux distributions (thanks to @ken_bauer for the links) :

• Ubuntu Desktop (Links to an external site.)Links to an external site. recommended 18.04 (Bionic Beaver) (Links to an external site.)Links to an external site. 
• Interim release 18.10 (Cosmic Cuttlefish) (Links to an external site.)Links to an external site.
• See more info about Ubuntu release cycles (Links to an external site.)Links to an external site..

Install support for your development environment.

The next step you can choose the language you like the most, but for this project I will use Java. Here is a very well explained tutorial in case you want to install Java in your Linux system

Java download process example

Java in action

Next step will be to set up the Github for pushing into a git repository

git in action, this is very important for the future steps

Setup web deployment.

I decided to use Node.js as my option for the web development. Be careful because for the Linux 18.04.1 LTS the typical node command has to be instead nodejs as seen in the next example

Node js server running on local host port 8080

Setup your 

This is the trickiest part, I’d recommend to first read the first test use of Cron in case you have never used it before, in other case, then just set it up for your desired functionalities

The background may seem different because I used the ITerm with ssh access to my VM

What is DevOps?

DevOps is a hot trend lately, but it’s not a new thing. This term is becoming real popular in recent years, (just like other terms as machine learning and agile methodologies),

The graph shows in blue the search numbers for the term Devops in Google. Graph taken from Google Trends

This chart is tricky since there weren’t that many Google internet users at 2004 to 2009 but still you can see the big raise of search numbers in recent years

This one is from 2014 until 2019. (It’s funny how every 3rd week of December the search goes down 🎅🏼🎄) .

So… what is DevOps exactly? According to the Agile Admin. This term is all about agile operations and the value of collaboration between development and the operations staff throughout all stages of the development lifecycle when creating and operating a service.

Developers + Operations = ??? = profit

credits to memegenerator.com (website filled with ads)

In other words, DevOps is the cooperation between the development and operations team and the people involved in the project to have a satisfactory delivery. It encapsulates the continuous delivery, automate deployment, designing the operability and monitoring.

The DevOps and the Agile methodologies are very tied together, nevertheless, DevOps and Agile are not the same thing.

In my experience, the DevOps team is the team everyone blames when a push is made into the development or any other phase and it doesn’t work properly. They are the sysadmins or masters of /Jenkins/Travis/etc… but this is not exactly the truth. DevOps is the answer to the fast pace of the modern world technology.

Continuous integration in testing

Thanks to the continuous integration which is a part of DevOps which is based on Agile, a developer can download a source code, test, build the system and verify the test! So mistakes made by developers are caught fast. So both DevOps and System tests in agile methods share the idea of “automate builds” including the verification tests. Sadly this process takes time, so the test have to be fast!

Like all the popular stuff, some people won’t like it (either having a reason or not). DevOps is popular so… some people say it’s the same thing sysadmins been doing forever just with more ceremonies and the agile principles. But I guess DevOps is a perfect solution for software development because more than just a term is a combination of tools, values, principles and practices that allow the delivery of projects at a higher velocity.

Discussion: TDD and Criteria-Based Test Design

Feature image by Roysneak (Rugby Scrum)

The book for reference in all the post is Introduction to Software Testing, 2nd Edition. 

• What is “correctness” in agile processes?

All agile methods have an underlying assumption that instead of defining all behaviours with requirements or specifications, we demonstrate some behaviours with specific tests. The software is considered correct if it passes all particular set of tests. But to be honest, no one is sure of what the term correctness mean when applied to a computer program.

• Do TDD tests do a good job testing the software?

Test Driven development is an agile approach (agile is a mindset not a methodology). So it’s a good tool to be responsive to change, because its focus is create a system that does something as early as possible. TDD allow us to obtain critical feedback quickly as possible. For example today at work something in the backend crashed, but it’s better that if it’s going to fail, that fail as quickly as possible. In conclusion, yes, it’s good depending your focus.

• Can we automate our tests without TDD?

Yes we can, automation is not unique to TDD

• Can we use TDD without automating our tests?

Yes we can, but this mean it will be manual, so it will have to spend more time and it will return the human factor. So in other words, it’s a no in disguise.

• What four structures do we use for test criteria?

1. Test requirement
2. Coverage criterion
3. Minimal test set
4. Minimum test set

• What usually prevents our tests from achieving 100% coverage?

As discussed later, there are infinite number of inputs and can’t be explicit enumerated. But we can divide up the input space to maximize the number of faults found per case. To be honest a 100% coverage is not even a realistic or possible goal. Secondly, some requirements can’t be satisfied and are very hard to find (as a purple M&M’s according to the book). Sometimes this is because the existence of dead code that can’t be reached.

Another reason, what does 100% even mean? Where is the criteria for saying how much worst is 99% from 100%.

• Some organizations in industry who adopt TDD report that it succeeds very well, and others report that it fails. Based on your knowledge of TDD and any experience you have, why do you think it succeeds sometimes but not all?

Even the book knows that the main cost of Agile methods for testing (in this particular case TDD) is that a lot of things are different. So it’s not easy for established teams and companies to change their mindset just like that. Therefore, sometimes TDD fits the project, sometimes it doesn’t. It’s not the methodology but how it’s implemented.

Image credits to New Line Cinema

• A few software organizations use test criteria and report great success. However, most organizations do not currently use test criteria. Based on your knowledge and experience, why do you think test criteria are not used more?

Based on my experience, test criteria is still used, but not as it used to be. It’s more about following what the user story specifies. The term complete testing or full coverage are poor designed because the potential inputs for most programs are unlimited.

In traditional software development, system requirement are often questionable in terms of how complete and current they are. In agile methods, they are undocumented! So what do system testers do?

Amman, P. and Offutt, J. (2016)

As the book say, there are no definite answer for test criteria.

References

Amman, P., Offutt, J. (2016) Introduction to Software Testing, 2nd Edition, Cambridge Press Chapter 4 and 5. https://cs.gmu.edu/~offutt/softwaretest/

Cover art by Peter Hoey http://www.peterhoey.com

The social side of a bug’s life

Logo of a Bugs life credited to Pixar

For this blog post I’ll use the word bug referring to either a fault/error/failure.

Jorge Aranda and Gina Venolia wrote a paper called The Secret life of Bugs.   (click here if you want to read it)In general it talks about how even simple bugs are very complicated to track with just automation, mostly because the human factor.

It’s very funny painful how sometimes when I work on a project, 40% of the time is dedicated to develop a functionality and the rest fixing the secondary effects. If this effect is a bug then I write an issue either on the repository or anything related to the project management. But here is the trick, as humans we believe we can keep track of everything in our minds, but in my experience I have seen a typical scenario:

(I | He | She | They | We ) will write about the bug later or in the next sprint

Something that will be fixed very late or never.

The authors Jorge and Gina have proof of why we can’t fully rely on electronic repositories a 100%. Which is mainly related to coordination problems.

Do we always record the necessary information to understand the whole story of the bug?

credits to computerservice.com

According to their studies the researched bugs databases had the next problems:

• Some bugs in the records are not bugs in strict sense.
• Some bugs have duplicate records
• Some bugs exhibit symptoms that are initially seen as different bugs and recorded separately
• Some bugs do not always die when they are marked as closed
• Some bugs basic field in the records are incorrect
• Some bugs have wrong status.
• Some life of bugs will never be understood without a face to face or personal investigation.

So in the end it is really interesting to see how when they tried to see the track of the life of the bug they reached dead ends. Or found that histories omitted important details of the bug. I believe our social human factor is the key to why we can’t trust 100% information extracted from electronic repositories.

Test a Calc Class

At first, this is our Calc class:

public class Calc {    
    static public int add (int a, int b) {
       return a + b;
    }
 } 

It only has the add method. Hence, we made failing tests for two methods to be implemented: mult and div, for multiplication and division. 

And a failing test for the add method as well.

The input values for the addition are incorrect. Also, the mult and div message are not recognized by the class.

As we can observe, all tests failed…

testAdd failed

testDiv failed

testMult failed

Then, we changed the testAdd input values, so the test won’t fail.

Now the addition will be correct.

Next, we implemented the methods for multiplication and division in the Calc class:

Calc now has three methods

Finally, we ran the tests again and had a successfull execution.

The class recognizes all Calc methods.