Streaming Pair Programming from AWS

 Posted on 2020 May 12  (Last modified on 2020 May 17)  |  Walter Schulze

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Why?

  • Why Streaming? One of the advantages of living in a big city, like London, is not just that you don’t have to own a car. It also makes it easier to find like minded people. People who are interested in learning the same thing you are and who are at a similar level in their learning experience on that topic, people you can form a study group with. I remember that working in, Stellenbosch, South Africa, I had to drive an hour and a half, one way, to Scarborough, Cape Town to find a group of about ten people interested in functional programming.

    Things have since changed with regards to functional programming at Stellenbosch University, where Haskell is now being taught in a popular choice module, but what if I wanted to study Coq programming next. What if there was a way to share some of the study group I found in London with others? Streaming on Twitch seems to be a way to accomplish this. What better place for streaming Coq, “the world’s geekiest computer game”.

  • Why Pair programming? Pair programming on a Coq project, where I am still learning the language, libraries and underlying theory, has been more educational to me than I could have ever imagined. If I was to share something, the pair programming had to be part of it.

  • Why AWS? tl;dr more CPU! A friend from the study group and I started pair programming some Saturdays in coffee shops. This evolved into a video call, where it was easy to include a whole study group. Video calling in general is not CPU friendly and Zoom is no exception. If you are also running OBS (the streaming software), you have two programs both competing for 250% of your 400% CPU. At some point typing into the editor, felt like I was typing into a remote terminal over a dial up modem. AWS allows us to rent a beast of a machine which could handle all of this including Teamviewer at 25% CPU.

Quick, everyone who knows what Twitch is Google what a dial up modem is and everyone who knows what a dial up modem is, you may now Google what Twitch is.

Setup

I thought streaming pair programming was going to be easy. I thought it would be as easy as Ted’s setup for remote pair programming on twitch with zoom, all running on my local machine.

My laptop couldn’t handle it and this required me needing to rent an AWS Server, which in turn led to a longer than expected setup process. I almost gave up when I was 90% done and needed some encouragement from a friend to push me over the finish line.

  1. Setup Twitch
  2. Find an appropriate AWS machine
  3. Ask amazon to lift CPU limit
  4. Update security group to enable remote desktop
  5. Launch and log into server using Remote Desktop
  6. Update internet explorer security
  7. Install and setup Teamviewer
  8. Install virtual sound card
  9. Install and setup Zoom
  10. Install and setup OBS
  11. Install and setup IDE
  12. Remap keys
  13. Choose a method of collaboration
  14. Stream

Setup Twitch

Technically you can stream to Twitch or Youtube. I chose Twitch, since this is apparently more popular with coders.

Go to twitch.tv and create an account.

Now we want to setup Twitch to preserve you videos for later viewing, so viewers don’t always have to watch at the exact time that the stream is occurring.

  • Click on Channel and Videos

  • Enable Store past broadcasts

Next you need an image to display on your channel when you are offline.

Scroll down to Video Player Banner and click Update.

Next click on the hamburger on the top left and then click on Stream Manager.

Under Quick Actions click Edit Stream Info

Finally set the Category as Science & Technology.

Unfortunately there is no coding category. Apparently there was one, but it has been shutdown and grouped into the Science & Technology category.

Find an appropriate AWS machine

We found the Microsoft Windows Server 2016 with NVIDIA GRID Driver machine. It is a g3.4xlarge, which has 16 cores. This setup with 16 cores ended up running at 25% CPU, so I wouldn’t recommend a 4 core machine. I chose windows over linux, because this is “the year of the linux desktop”. If you are new to AWS, you won’t be able to launch this yet and you will need to increase your CPU limit, see instructions in the next section.

This server looks expensive and it is not cheap, but given you are only paying for it when it is running, if you are disciplined in stopping the server, when you are not using it, it can be affordable, depending on how much you intend to use it. Now is a good time to make that calculation and decide whether you can live with the hourly rate, which is about $2 per hour, at the time of writing.

Ask Amazon to lift CPU Limit

  • Create an AWS account or log into your existing one by going to your AWS Console
  • At the top, click Services and from the menu under Compute select EC2
  • On the side menu, click Limits
  • Search for CPU and select Running On-Demand All G instances, this is if you also chose a machine that starts with g, like the g3.4xlarge. If you are new to AWS, like me, you will need to increase your Current Limit from 0 to 16 to be able to launch the chosen machine. I selected 32, just in case. If your limit is already high enough you can skip this section.
  • Click Request limit increase in the top corner.
  • A form will open:
    • Make sure EC2 Instances is selected for Limit type
    • Select your Region, All G instances if you are requesting a machine that starts with g, like the g3.4xlarge. Choose a New limit value of 16 if that is appropriate for your selected machine, like the g3.4xlarge.
    • Finally describe your use case in the Use case description box.
  • And now you will have to wait for amazon’s human reviewers to look at the case and decide whether to increase the limits. I waited about 3 days.
  • Then you should be able to launch in the instance.

Update security group to enable remote desktop

AWS Windows servers don’t let you log into them using remote desktop by default. You have to create a new security group or update the default security group to allow for RDP traffic.

  • go to AWS Console
  • go to EC2
  • On the left, under Network & Security, click on Security Groups.
  • Now you need to Create security group or Edit Inbound Rules for an existing group. To edit an existing group, for example the default Security group, like I did: Select it, click on Actions and then Edit Inbound Rules.
  • Next, add two new rules, using the Add Rule button: Type: RDP, Source: 0.0.0.0/0 and Type: RDP, Source: ::/0
  • Finally click Save rules. Now you should be able to use remote desktop to log into your server.

Launch and log into server using Remote Desktop

If AWS has approved your CPU limit increase, you can move onto this step.

  • If you are on a mac, like me, you will need to install remote desktop.
  • Now is the time to launch your instance Microsoft Windows Server 2016 with NVIDIA GRID Driver
    • click on Continue to Subscribe. This doesn’t cost anything for this specific instance, since it is an instance marketed by AWS themselves, but other instances on AWS Marketplace, might cost a subscription fee.
    • click on Continue to Configuration
    • pick your specific region, we chose EU (Ireland).
    • check that the Software Pricing is $0/hr if you haven’t chosen a different machine. Infrastructure Pricing should have a real cost associated with it.
    • click on Continue to Launch
  • go to EC2
  • click on Instances on the left side menu.
  • Now the machine might already be started, or initializing, but if is not, then right click on the instance, select Instance State and then Start.

  • Wait for Status Checks to turn from Initializing to 2/2 checks passed.
  • Right click on your machine and click Connect

  • Click on Download Remote Desktop File

  • You will also need to click Get Password, but I will leave those details up to you.
  • Now open the downloaded remote desktop file, using remote desktop.
  • You will need to paste in the password you got from Get Password.
  • Well done! You can now remotely control the AWS windows server, from your home computer, using remote desktop.
  • Before you possibly stop your machine, remember to create an image in the AWS E2 Instances, otherwise you could lose your work?

Update Internet Explorer security

This first problem you will encounter on your windows server, is Internet Explorer has been severely limited, via a security setting. Basically, you won’t even be able to download another browser. Let’s fix that.

On your windows server, via Remote Desktop:

  • Open Server Manager

  • In the left panel, Select Local Server

  • In the top panel with heading Properties, in the right middle of that panel, you will see IE Enhanced Security Configuration. Mine already, says Off, but yours will say On.

  • Click on On and select Off for both users and Administrator.

  • Click Ok.
  • Close Server Manager
  • Open Internet Explorer, it should now show that Caution: Internet Explorer Enhanced Security Configuration is not enabled.

  • Download and install your browser of choice.

Install and setup Teamviewer

Why do we need Teamviewer, when Remote Desktop is working so well? It all comes down to sound. A server doesn’t have a sound card, but we want to stream the sound from our video call to Twitch. We will need to install a virtual sound card and this doesn’t play nicely with Remote Desktop.

VNC is another option, but we opted for Teamviewer, because we will need cloud connect for a user friendly experience and this is free for personal use on Teamviewer, where I found with VNC servers that it looked like I needed to pay. I could be wrong. In the end Teamviewer was more user friendly for me and solved the sound problem.

  • Install Teamviewer on your mac and windows server.
  • Once installed, on the windows server, Sign in or create a Teamviewer account and sign in.
  • On the windows server, Tick Start Teamviewer with Windows and Easy access for ... is granted.

  • On your mac, sign into your Teamviewer account.
  • You should now see the machine under Computer & Contacts.
  • Double Click on the machine to connect.
  • You should get a notification about multiple monitors. This server has two virtual monitors, which is going to be very useful for streaming. Click Ok

  • You should now see a locked screen, that requires Ctrl+Alt+Delete to unlock. Click on Actions in the top menu bar and then select Ctrl+Alt+Delete.
  • You should now be able to log into your Administrator account. You might have a problem here, which is copy and paste is not working, at least it didn’t work for me.

  • Click on Actions again in the top menu bar and then select Send key combinations. Try again. You might still have a problem, just like me. You are not alone, but it did eventually start working. Unfortunately, I never got to understand why.

  • Now is as good a time as any to create a user account. If you are unable to log into Teamviewer, yet. Go to remote desktop and create a user account, with a password that you can remember and type without copying and pasting. You can keep your Administrator account secure and only ever need to use it with Remote Desktop. Only your user account will need to work with Teamviewer and might need a password that you can actually remember and type out.

  • Now you can use Teamviewer to log into your user account.

  • One more thing I would encourage you to Configure is to Optimize for speed over quality of image. If you are planning to code, then typing is a big part of that and typing feedback can be very important. Go to Teamviewer’s Preferences. Click on Remote Control and from the Quality dropdown, select Optimize speed.

Install virtual sound card

On the windows server:

  • Download VB-Audio Software’s VB-Cable. We don’t need the VB-Cable A+B, etc. We only need the VBCABLE_Driver_Pack43.zip.
  • Unzip and run VBCABLE_Setup_x64.
  • In Teamviewer, go to your sound card settings, by right clicking in the bottom right corner on the little speaker and selecting Playback devices.

  • Under Playback you should see Cable Input by VB-Audio Virtual Cable. Please ignore the other playback devices, I tried several routes before realizing remote desktop was incompatible with virtual sound cards and I haven’t taken the time to clean up the other virtual sound cards I ended up not using or even evaluating.

  • The virtual sound card is now installed, we are going to use it to thread the zoom output sound into OBS input sound and stream this to Twitch.

Install and setup Zoom

I chose Zoom, because:

  • Zoom allows screen sharing and doesn’t turn off your webcam to do so.
  • Zoom’s window in which participants are viewed is the prettiest to put in a corner of your screen and has always on top enabled automatically.

I might reconsider this choice in future, since Zoom calls over 40 minutes are not free and removing this from the setup would moderately reduce the overall cost of this setup.

Whichever Video Call program you choose, it is important to setup the sound output. Here is how I did it for Zoom, but you should easily be able to reproduce this with any Video Calling program.

  • Install Zoom on your windows server and create a new account. You are going to need two accounts for Zoom. One for the windows server and one for your home computer. Only the account that will be hosting the meetings will need to be a paid account, if you are planning on pair programming longer than 40 minutes at a time, like me.
  • Go to Zoom settings and then Audio. Set the Speaker to CABLE Input (VB-Audio Virtual Cable), the Microphone doesn’t matter as we won’t be using the server’s microphone.

Now Zoom will send its output, which should include everyone on the call’s audio to CABLE Input.., which we are going to capture using OBS.

Install and setup OBS

OBS Studio is used to Stream to Twitch, Youtube, etc. Now is probably a good time to skim through a better blog to learn a bit more about OBS and how to use it. There are also many videos that explains how to setup OBS. We will not be going into that. We will only be touching on the specific OBS configuration for this setup, namely how to route the audio and how to share our screen using the multiple monitors of this AWS Server.

  • Log into your windows server as Administrator. Installing OBS requires being logged in as Administrator, so I installed it using Remote Desktop.
  • Download and install OBS Studio and setup connection to Twitch. There should be step by step instructions for doing so.
  • After installation, we can log back into our user, using Teamviewer.
  • Go to View in the top menu bar, under Active monitor, click Show all monitors.

  • Open OBS Studio and drag it to the smaller second monitor. Your OBS will be less interesting than mine, since mine is already setup. OBS will be running on the small monitor 2 and we will be using monitor 1 for everything we want to stream to Twitch.

  • We can capture the sound from zoom that we have routed to CABLE Input (VB-Audio Virtual Cable) in OBS, by first creating a Scene. Click the + button in the Scene panel.

  • Select our new scene and click the + button under Sources and select Audio Output Capture.

  • Select Create New, type a name and click OK.
  • Select the Device from the dropdown: CABLE Input (VB-Audio Virtual Cable) and click OK.

  • You should now be able to test the sound, by creating a Zoom call between your home computer and the windows server and see the green bar in the Audio Mixer move, when you talk.

  • We can capture monitor 1, by adding another Source. Click the + under Sources and select Display Capture.

  • Select Create New, type a name and click OK.
  • Select the Device from the drop down Display 1... and click OK.

  • You can now test the sound and display by clicking the Start Recording button in OBS, creating a zoom call and watching and listening to yourself speak, by playing the recorded file.

Install and setup IDE

This setup is specific to VSCode and Coq, but you can install any IDE for any programming language you want.

  • Install VSCode
  • Install your programming language, in our case Coq
  • Install your VSCode plugin, in our case VSCoq and make sure it points to your Coq installation.
  • Turn off some suggestions. Suggestions are great for auto complete, but if they happen when you simply type space they can be disruptive and possibly over work the language server. I found turning this one setting off Editor > Suggest: Show Properties in vscode, results in hints from VSCoq to only happen after I have typed some letters.

Remap keys

Controlling a windows machine from a mac, means that several of your usual shortcuts no longer work. Mac uses the Cmd key, where windows uses Ctrl key a lot. This is a simple fix on your mac. Go into your keyboard settings, select Modifier Keys and remap Cmd to Ctrl.

For the rest, I use Autohotkey to remap my most popular mac shortcuts to windows shortcuts.

  • Log in as Administrator.
  • Install AutoHotkey on your windows server.

Create a script file: mac.ahk

;Autohotkey script

;Ctrl+Shift+Left => Shift+Home
^+Left::Send +{Home}
;Ctrl+ShiftRight => Shift+End
^+Right::Send +{End}

^w::Send ^{F4}
^q::Send !{F4}

This script has to run as Administrator. Right click on the file and choose Run as Administrator, when you log in as your normal user. I needed to have Teamviewer’s Send key combinations enabled, others have reported the opposite so play around with this.

Choose a method of collaboration

If you want to do collaborative editing, instead of just having your pair programmers, be backseat coders. There are several options:

  • Teamviewer allows for multiple logins and that works great, since now your collaborators have full control. You need to coordinate who is using the keyboard. Also less obviously you are also sharing a copy and paste buffer. So if one of you is doing something on their own computer and copies something, the other person can paste this into teamviewer onto your public stream, so be careful about copying passwords, etc.
  • Alternatively you can install Live Share, but we couldn’t get this working with Coq’s Proof View. I hope we are wrong, because this would solve a lot of problems.
  • Screen share via Zoom allows multiple collaborators to switch between who is driving. Yes technically the server doesn’t have to be the one that is sharing its screen with your collaborators. Your collaborators can actually share their local screen and this shared screen can then be captured with OBS on the AWS server and streamed to Twitch. In this case collaborators with limited CPU, might want to limit the amount of frames they are sharing.
  1. Go to Zoom Settings
  2. Click Share Screen
  3. Click the Advanced button in the lower right hand corner.
  4. Check the Limit your screen share box
  5. Select 4 frames-per-second.

Stream

Finally you are ready to stream.

You will probably want to create pictures that you can use to display when you are:

  • Offline
  • Starting Soon
  • Taking a Break and possibly
  • Entering a password

Come check out the resulting stream: https://www.twitch.tv/awalterschulze

Thank you

  • Ayman Osman for the idea of using AWS, tutoring me in how to use AWS and also encouraging me when I was about to give up.
  • Max Heiber for the initial idea to stream Coq programming.
  • Paul Cadman for testing and searching and finding a way to limit the number of frames in Zoom, when my CPU was still struggling.
  • Niels uit de Bos for testing the stream.
twitch  aws  teamviewer  pair programming  zoom  coq  vscode