Tag: BitBucket

Downtime? Time to Build!

The COVID-19 pandemic has caused many of us to stay isolated and at home, but that’s OK! I genuinely enjoy developing software and wanted to take this opportunity to focus on learning. Having some downtime has afforded me to try putting together a system that I otherwise might not have explored building.

In this article, I’ll share different aspects about an application I’m building that purposefully put me outside of my comfort zone. In my opinion, having downtime is an opportunity to learn and grow! It’s time to take advantage of that.

When the app and system is ready to showcase I’ll share more insight into what’s actually being built!

The Client Framework

The application being built was intended to run on multiple mobile platforms, so Xamarin was my choice here. I have briefly used Xamarin several years ago, but my reasons for this time through were:

  • C#, .NET, and Visual Studio support. There were many things I wanted to learn about, but I wanted to limit myself to a familiar foundation so that I could still feel that I’m making progress.
  • Supports iOS and Android right from the start. I thought it would be an interesting software design challenge to be able to build base components in a shared library and then leverage dependency injection for platform-specific components.
  • Traction. Xamarin has been around for a number of years now, and it’s only continuing to gain support. I didn’t want to focus on a platform or SDK that wasn’t getting any love.

Xamarin was easy to get setup with because of the familiar pieces, but I was pushed out of my comfort zone to learn about how certain things are handled differently on iOS and Android

I was able to learn about:

  • Android/iOS permission requests
  • The new UI controls in Xamarin (vs WPF which I’m used to)
  • More practice with async/await and UI experience
  • Different mobile API frameworks (Crashlytics, Google Analytics, user control libraries)

The Server Framework

I’ve joked with my colleagues in the past that “web isn’t my thing”, but what I really mean is that “I don’t have experience making web pages”. I’ve build many client server systems in my professional experience and hobby programming, but serving nice-looking web pages hasn’t been my strength.

For the system that I’m designing in my downtime, I need an application server. I decided to go with ASP.NET Core because I haven’t set up many ASP.NET systems before, and I don’t have experience having them hosted in the cloud. However, I do have experience with C# and Visual Studio, so again, this seemed like a good balance of trying new things with some familiar concepts to ensure I could make progress.

In short order, I was able to get a handful of application server routes setup and communicating with the client application properly. The most difficult part was truly just making sure firewall and SSH settings were configured locally, and a handful of times of cursing at my phone for not having it on WiFi (and thus not seeing the development server on my local network)!

I was able to learn about:

  • Authentication attributes (and JWT token handling)
  • Routes with query parameters
  • Serving static content as well as application requests

The Authentication Framework

This one was fun. Having a professional career in software development, one thing that scares everyone away is designing authentication and user management. Nobody wants to because it’s complex, has plenty of edge cases, and… it’s probably critical to your system working 🙂

Thankfully, Firebase saved the day. I wrote about this already, but Firebase truly made authentication and user management way more straight forward than I’m used to. The hardest parts of working with Firebase had nothing to do with Firebase and everything to do with implementing OAuth for the providers of my choosing.

Because I could use OAuth to authenticate users and have identifiable information provided via a JWT, having a simple registration and login system that mapped OAuth’d users to some sort of internal-system user identifier was trivial. All of the routes for my web application could also authenticate and control access via this same JWT! One of the scariest components about building a system became a relatively light lift.

I was able to learn about:

  • OAuth for popular providers (Google, Facebook, etc…)
  • OAuth scopes
  • JWT tokens
  • Firebase SDK from a server and client side
  • Route authentication in ASP.NET using JWTs

The Database Framework

As part of the journey for exploring unfamiliar technology in my downtime, I decided I’d like to pursue a database that wasn’t SQL-based. I was already using Firebase for authentication and Google offers an intriguing document store in Firebase that provides real-time update triggers.

Being unused to document databases (I’m much more familiar with relational databases), I spent some time trying to design my schemas that I intended to use. One thing that caught me off guard pretty quickly was that in order to modify to a list of things, I’d need to have a local copy of the list, manipulate the collection, and then push the entire structure back to replace the existing structure. This seemed like overkill what I was trying to do, but the alternative was that I could modify objects in the data store to add/remove child items, but each child item would receive another identifier object as a linking object. So a list of X things actually meant 2X things (one for the identifier, one for the entry). Again, this was overkill.

I decided to go back to familiar technology but explore a not so familiar space! I have a good deal of experience working with SQLite and MySQL from my career. What I don’t have a lot of experience with is the management and provision of a MySQL instance with availability in the cloud! Enter Amazon RDS!

Switching to Amazon RDS meant a bit of a learning curve for making sure I could host and configure an instance of MySQL in the cloud. I was able to learn about various Amazon AWS services and roles and how they play together. But once the instance was up and running, I was able to get up and running effectively.

The Tooling

I had help with this one, fortunately, from a friend and old colleague of mine Graeme Harvey. If you’ve worked with me professionally or on a hobby project, one of the things I admit pretty quickly is that I really dislike tinkering to get a configuration right. Generally this is because there’s a lot of tweaking to get something set up right, documentation to understand, and frustrating trial and error.

Source control was going to be git. I didn’t even want to consider anything else. Git is so widely used now that I didn’t see a real benefit to trying to learn a new source control system. Repository management though? BitBucket. I’m a huge fan of the Atlassian suite of products having used them professionally for many many years.

And with that said Jira for issue management. Again, I’ve used Jira professionally for many years. What I’ve never done is had my own Jira instance though! This was made very simple by Atlassian, and not being a company that’s generating big bucks I was able to get the free tier that handles all of my needs. Jira is straight up awesome for issue management and visibility into your ongoing work.

Another no-brainer for me was getting Slack setup. Slack is something I’ve used a lot professionally but like Jira, I’ve never had my own Slack instance. Simple to setup and works just like I’m used to in my career. This wasn’t really a huge requirement but working with another person provided a nice workspace for chatting about stuff we were working on.

And finally… builds. I wrote about using Circle CI to get our server builds up and running already, and to re-iterate it was extremely simple. I even have them wired up to report back to Slack when we push code up to BitBucket! Where we’re still having some fun is figuring out how to deploy our application server builds to an EC2 instance automatically. This would allow us to “release” to a branch and have production hosting of our application server get updated in the cloud!

But we’re building a mobile application in Xamarin, so we have three outputs:

  • The application server in ASP.NET
  • The Android client
  • The iOS client

Mobile app development gets interesting because what you’re actually building is intended to run on a device and not a desktop/server… And why that matters is that generally your desktop or server application will be output as a binary, but your mobile application will be some sort of package you’ll need to sign and distribute on an app store.

After some back and forth, we decided to explore App Center. If I’m being honest, this was equally as easy to setup for our iOS and Android apps using Xamarin as our server was to setup using Circle CI for builds. App Center provided a simple wizard for triggering off of our BitBucket repositories getting new commits to a branch, and the rest was done for us.

What I learned:

  • Git+BitBucket = Free git repository hosting (private if you want) and plenty of integrations
  • Jira = Free issue management and kanban board with plenty of integrations
  • Slack = Free chat workspace with plenty of integrations
  • CircleCI = Free continuous builds with integrations into ALL the other things I just mentioned 🙂
  • App Center = Free continuous builds for iOS and Android Xamarin apps with plenty of integrations!

In Summary

It’s been a couple of weeks of getting to try building out this project and setting up these different systems to go to work for me. I’ve been able to learn a lot about new or previously unexplored SDKs/technology and even learn some different facets of things I already have professional experience with.

I’m not one to sit idle… So using my downtime to learn cool things and build something has been an awesome time! I’d highly recommend that if you’re in quarantine, lockdown, or otherwise unable to really get out and do too much that you try your hand at something new! Get creative. Get learning.

Be safe and stay healthy!


CircleCI + BitBucket => Free Continuous Integration!

CircleCI is a service that I heard about from a friend that allows you to get continuous integration pipelines built up for your repositories… And it does it quick and easy. Also, free if you’re someone like me and you don’t have a large demand for getting builds done! I wanted to write about my experience with getting CircleCI wired up with BitBucket, which I like to use for my project hosting, and hopefully it’ll help you get started.

First thing, signing up is super easy if you have BitBucket because you can oauth right away with it. CircleCI will show you your projects & repositories that you have in BitBucket and you can decide which one you’d like to get started with. You can navigate to the projects in their new UI from the “Add Projects” menu.

CircleCI Left Navigation

When you click “Add Projects” you’ll be met with a list that looks like this but… With your own projects and not mine 🙂

Circle CI + BitBucket Project Listing

On this screen, you’ll want to select “Set Up Project” for the project of your choice. For me, I was dealing with a .NET project (which I’ve already setup) so I selected it and was presented with the following screen. It also allows you to pick a template out to get started:

CircleCI Template Dropdown

However, I needed to change the default template to get things to work properly when I had nuget packages! We’re missing a restore step. With some help from my friend Graeme, we were able to transform the sample from this:

 version: 2.1

 orbs:
  win: circleci/windows@2.2.0

 jobs:
   build:
     executor: win/default     
    
     steps:
       - checkout
       - run: dotnet build

To now include the nuget restore step prior to building!

 version: 2.1

 orbs:
  win: circleci/windows@2.2.0

 jobs:
   build:
     executor: win/default     
    
     steps:
       - checkout
       - run:
          name: Restore
          command: dotnet restore
       - run:
          name: Build
          command: dotnet build -c Release

Once you save this, CircleCi will make a branch called “circleci-project-setup” on your remote. It then goes ahead and runs your build for you! When the build for this new remote branch succeeded, I pushed this configuration to my “master” branch so that all builds on master going forward would get continuous integration builds.

Checking the CircleCI dashboard now looks like the following:

CircleCI Successful Pipelines

You can see pipeline #1 is on the branch where the test circleci configuration was made (and passed). Pipeline #2 is once I added this commit onto my master branch and pushed up! Now I have continuous integration for pushing to my lib-nexus-collections-generic BitBucket project. When I check out my commit page, I can see the new commits after the configuration landed get a nice green check when the builds pass on CircleCI:

BitBucket Commit Listing With Builds

So with a few easy steps, you can not only have free source hosting in BitBucket but free continuous integration from CircleCI. Every time you push code to a remote branch, you kick off a build! This is only the starting point as you can configure CircleCI to do much more than just restore nuget packages and build .NET solutions 🙂


IronPython: A Quick WinForms Introduction

IronPython: A Quick WinForms Introduction

Background

A few months ago I wrote up an article on using PyTools, Visual Studio, and Python all together. I received some much appreciated positive feedback for it, but really for me it was about exploring. I had dabbled with Python a few years back and hadn’t really touched it much since. I spend the bulk of my programming time in Visual Studio, so it was a great opportunity to try and bridge that gap.

I had an individual contact me via the Dev Leader Facebook group that had come across my original article. However, he wanted a little bit more out of it. Since I had my initial exploring out of the way, I figured it was probably worth trying to come up with a semi-useful example. I could get two birds with one stone here–Help out at least one person, and get another blog post written up!

The request was really around taking the output from a Python script and being able to display it in a WinForm application. I took it one step further and created an application that either lets you choose a Python script from your file system or let you type in a basic script directly on the form. There isn’t any fancy editor tools on the form, but someone could easily take this application and extend it into a little Python editor if they wanted to.

Leveraging IronPython

In my original PyTools article, I mention how to get IronPython installed into your Visual Studio project. In Visual Studio 2012 (and likely a very similar approach for other versions of Visual Studio), the following steps should get you setup with IronPython in your project:

  • Open an existing project or start a new one.
  • Make sure your project is set to be at least .NET 4.0
    • Right click on the project within your solution explorer and select “Properties”
    • Switch to the “Application” tab.
    • Under “Target framework”, select  “.NET Framework 4.0”.
  • Right click on the project within your solution explorer and select “Manage NuGet Packages…”.
  • In the “Search Online” text field on the top right, search for “IronPython”.
  • Select “IronPython” from within the search results and press the “Install” button.
  • Follow the instructions, and you should be good to go!

Now that we have IronPython in a project, we’ll need to actually look at some code that gets us up and running with executing Python code from within C#. If you followed my original post, you’ll know that it’s pretty simple:


var py = Python.CreateEngine();
py.Execute("your python code here");

And there you have it. If it seems easy, that’s because it is. But what about the part about getting the output from Python? What if I wanted to print something to the console in Python and see what it spits out? After all, that’s the goal I was setting out to accomplish with this article. If you try the following code, you’ll notice you see a whole lot of nothing:


var py = Python.CreateEngine();
py.Execute("print('I wish I could see this in the console...')");

What gives? How are we supposed to see the output from IronPython? Well, it all has to do with setting the output Stream of the IronPython engine. It has a nice little method for letting you specify what stream to output to:


var py = Python.CreateEngine();
py.Runtime.IO.SetOutput(yourStreamInstanceHere);

In this example, I wanted to output the stream directly into my own TextBox. To accomplish this, I wrote up my own little stream wrapper that takes in a TextBox and appends the stream contents directly to the Text property of the TextBox. Here’s what my stream implementation looks like:


private class ScriptOutputStream : Stream
{
  #region Fields
  private readonly TextBox _control;
  #endregion

  #region Constructors
  public ScriptOutputStream(TextBox control)
  {
    _control = control;
  }
  #endregion

  #region Properties
  public override bool CanRead
  {
    get { return false; }
  }

  public override bool CanSeek
  {
    get { return false; }
  }

  public override bool CanWrite
  {
    get { return true; }
  }

  public override long Length
  {
    get { throw new NotImplementedException(); }
  }

  public override long Position
  {
    get { throw new NotImplementedException(); }
    set { throw new NotImplementedException(); }
  }
  #endregion

  #region Exposed Members
  public override void Flush()
  {
  }

  public override int Read(byte[] buffer, int offset, int count)
  {
    throw new NotImplementedException();
  }

  public override long Seek(long offset, SeekOrigin origin)
  {
    throw new NotImplementedException();
  }

  public override void SetLength(long value)
  {
    throw new NotImplementedException();
  }

  public override void Write(byte[] buffer, int offset, int count)
  {
    _control.Text += Encoding.GetEncoding(1252).GetString(buffer, offset, count);
  }
  #endregion
}

Now while this isn’t pretty, it serves one purpose: Use the stream API to allow binary data to be appended to a TextBox. The magic is happening inside of the Write() method where I take the binary data that IronPython will be providing to us, convert it to a string via code page 1252 encoding, and then append that directly to the control’s Text property. In order to use this, we just need to set it up on our IronPython engine:


var py = Python.CreateEngine();
py.Runtime.IO.SetOutput(new ScriptOutputStream(txtYourTextBoxInstance), Encoding.GetEncoding(1252));

Now, any time you output to the console in IronPython you’ll get your console output directly in your TextBox! The ScriptOutputStream implementation and calling SetOutput() are really the key points in getting output from IronPython.

The Application at a Glance

I wanted to take this example a little bit further than the initial request. I didn’t just want to show that I could take the IronPython output and put it in a form control, I wanted to demonstrate being able to pick the Python code to run too!

Firstly, you’re able to browse for Python scripts using the default radio button. Just type in the path to your script or use the browse button:

IronPython - Run script from file

Enter a path or browse for your script. Press “Run Script” to see the output of your script in the bottom TextBox.

Next, press “Run Script”, and you’re off! This simply uses a StreamReader to get the contents of the file and then once in the contents are stored in a string, they are passed into the IronPython engine’s Execute() method. As you might have guessed, my “helloworld.py” script just contains a single line that prints out “Hello, World!”. Nothing too fancy in there!

Let’s try running a script that we type into the input TextBox instead. There’s some basic error handling so if your script doesn’t execute, I’ll print out the exception and the stack trace to go along with it. In this case, I tried executing a Python script that was just “asd”. Clearly, this is invalid and shouldn’t run:

python_error_asd

Python interpreted the input we provided but, as expected, could not find a definition for “asd”.

That should be along the lines of what we expected–The script isn’t valid, and IronPython tells us why. What other errors can we see? Well, the IronPython engine will also let you know if you have bad syntax:

python_error_bad_syntax

Python interpreted the script, but found a syntax error in our silly input.

Finally, if we want to see some working Python we can do some console printing. Let’s try a little HelloWorld-esque script:

python_pass_hello_world

Python interpreted our simple Hello World script.

Summary

This sample was pretty short but that just demonstrates how easy it is! Passing in a script from C# into the IronPython is straight forward, but getting the output from IronPython is a bit trickier. If you’re not familiar with the different parts of the IronPython engine, it can be difficult to find the things you need to get this working. With a simple custom stream implementation we’re able to get the output from IronPython easily. All we had to do was create our own stream implementation and pass it into the SetOutput() method that’s available via the IronPython engine class. Now we can easily hook the output of our Python scripts!

As always, all of the source for you to try this out is available online:

Some next steps might include:

  • Creating your own Python IDE. Figure out some nice text-editing features and you can run Python scripts right from your application.
  • Creating a test script dashboard. Do you write test scripts for other applications in Python? Why not have a dashboard that can report on the results of these scripts?
  • Add in some game scripting! Sure, you could have done this with IronPython alone, but maybe now you can skip the WinForms part of this and just make your own stream wrapper for getting script output. Cook up some simple scripts in a scripting engine and voila! You can easily pass information into Python and get the results back out.

Let me know in the comments if you come up with some other cool ideas for how you can leverage this!


  • Subscribe to Blog via Email

    Enter your email address to subscribe to this blog and receive notifications of new posts by email.

  • Nick Cosentino

    Nick Cosentino

    I have nearly a decade of professional hands on software engineering experience in parallel to leading multiple engineering teams to great results. I'm into bodybuilding, modified cards, and blogging about leadership/development topics over at http://www.devleader.ca.

    Verified Services

    View Full Profile →

  • Copyright © 1996-2010 Dev Leader. All rights reserved.
    Jarrah theme by Templates Next | Powered by WordPress