Continuous Delivery with TFS, VSTS, and Azure DevOps

by | Nov 25, 2019 | DevOps | 0 comments

tfs,vsts,azure devops

In this article we tackle all of the common challenges encountered when trying to do continuous integration with Azure DevOps aka VSTS aka TFS. Some critical topics that are tackled here are:

  • How to work with Azure DevOps environment variables
  • How to create a build pipeline

By the way, if you aren’t aware, TFS, VSTS and Azure DevOps are all technically the same solution. Over several years, Microsoft did a lot of rebranding that created the confusion between all of these products. Hence it went from TFS to VSTS to Azure DevOps relatively quickly. Causing lots of confusion. The latest version is called Azure DevOps. I hope that it stays with this name for the foreseeable future 🙏

Automation pipeline in Azure DevOps with .NET Framework

In this section, we will cover automated testing pipelines in Azure Pipelines.

Working Azure DevOps pipeline with automated tests in .yml

https://gist.github.com/nadvolod/742a5cfcaac71324beb8cc34101f3a9d
Example Azure DevOps pipeline using .NET Framework with automated UI tests

Staged test execution in Azure DevOps

What if you want to run different suites in your Azure pipeline so that you have a gated release. For example, you should be trying to run unit tests first, followed by integration tests, followed by acceptance tests. In that case, you need the ability to filter.

By default, Azure DevOps will attempt to run all of your tests in your solution. Regardless of whether you are using NUnit or MsTest or something weird like XUnit (although I never tried with this and wouldn’t)

When you add a VS Test task to your pipeline, this default configuration will run all your tests

YAML file to run tests

https://gist.github.com/nadvolod/742a5cfcaac71324beb8cc34101f3a9d

Important points about YAML file

I couldn’t get searchFolder to filter out directories

However, using testAssemblyVer2 worked really well

Filtering tests using Azure DevOps

In order to be able to have a staged test execution in our continuous integration pipeline, we need to be able to filter our tests. I have 100s of tests in this repo but I would only like to run the tests that have [Category(“BestPractices”)] from Nunit.

Furthermore, I would like to exclude all of the performance tests, even though they are also categorized as “BestPractices”. As a result, the configuration of our Azure DevOps task looks like this.

test filtering in azure devops

And here is what the same exact thing looks like in a .yml

steps:
- task: VSTest@2
  displayName: 'Run Best Practices Tests without performance'
  inputs:
    testFiltercriteria: 'TestCategory=BestPractices&TestCategory!=Performance'
    runInParallel: true
    testRunTitle: 'Best Practices Tests'

More on the filtering capabilities in Azure DevOps aka VSTS aka TFS

UI Automation in Sauce Labs

UI Automation CI pipeline using YAML with Sauce Labs

https://gist.github.com/nadvolod/742a5cfcaac71324beb8cc34101f3a9d
Working example of an Azure DevOps pipeline that runs automated UI tests in Sauce Labs.

How to set Sauce Labs environment variables in Azure DevOps with .NET Core?

These are instructions if you are working with .NET Core

1. Create environment variables in Azure DevOps and assign them secret values

Adding Variables to your pipeline

Here’s an example

My recommendation is that you name the variables to something similar that I have above. Do not name your ADO variables the same as your Environment variables as that will cause you issues when you are trying to read them. So don’t name your ADO variable SAUCE_USER_NAME for example

2. Pass values from environment variables to variables in the source code

For this to work, you need to be reading values into environment variables exactly like this:

// testFile.cs
var sauceUserName = Environment.GetEnvironmentVariable("SAUCE_USERNAME");
var sauceAccessKey = Environment.GetEnvironmentVariable("SAUCE_ACCESS_KEY");

Make sure that you do NOT set the EnvironmentVariableTarget.User as your 2nd parameter as Azure DevOps will not be able to read that variable.

3. Configure .yml to read values from Azure pipelines and set them into system environment variables

Your YAML needs this piece of code to be able to set environment variables of the Azure DevOps box 

#need to use the vso tasks so that the env variables persist trhough tasks in ADO
- powershell: |
   Write-Host "Our Sauce Username in ADO is=> $($env:SAUCE_USER)";
   Write-Host "Our Sauce Access Key in ADO is=> $($env:SAUCE_KEY)";
   Write-Host ("##vso[task.setvariable variable=SAUCE_USERNAME]$($env:SAUCE_USER)")
   Write-Host ("##vso[task.setvariable variable=SAUCE_ACCESS_KEY]$($env:SAUCE_KEY)")

Learn more about VSTS aka Azure DevOps logging commands. Check out this repo with a fully working example.

Extra resources

An excellent blog about environment variables in ADO

Set Sauce Labs environment variables in Azure DevOps with .NET Framework?

Using task.setvariable

One way to set environment variables in Azure DevOps is to ##vso[task.setvariable

In the .yml, specify code that looks like this

- powershell: |
   Write-Host "Our Sauce Username in ADO is=> $($env:SAUCE_USER)";
   Write-Host "Our Sauce Access Key in ADO is=> $($env:SAUCE_KEY)";
   Write-Host ("##vso[task.setvariable variable=SAUCE_USERNAME]$($env:SAUCE_USER)")
   Write-Host ("##vso[task.setvariable variable=SAUCE_ACCESS_KEY]$($env:SAUCE_KEY)")

The last 2 lines are the important ones. They state that we should set environment variable SAUCE_USERNAME with the value of $($env:SAUCE_USER). SAUCE_USER is a variable that was defined in Azure DevOps.

Using a Powershell script

This is a more complicated approach than above.

  1. First you need to create some environment variables in your Azure DevOps UI that you want to use for values. This is an example of a variable that I would like to set on the test agent for my automation scripts. For example sauce.userName. I will use the value of this variable(sauce.userName) and have a Powershell script set it in my System Environment Variables of the test agent when my automation is running. That way, the value of this variable isn’t exposed to the public.

2. Next, you will want to create a Powershell script that you attach to your solution. Here’s my solution layout.

.ps1 solution structure
Powershell script placed at the root of the solution

Don’t forget to make sure to copy your Powershell script to output directory on build in your .csproj

Here is what you want in your Powershell script. 

Param(
[string]$sauceUserName,
[string]$sauceAccessKey,
[string]$rdcVodQaNativeAppApiKey,
[string]$rdcSauceDemoIosRdcApiKey
)
Write-Output "sauce.userName value from ADO was passed as a Argument in the ADO Task called $env:SAUCE_USERNAME " +
"to sauceUserName variable in the Posh. This is the value found=>$sauceUserName"
Write-Output "sauce.accessKey that was passed in from Azure DevOps=>$sauceAccessKey"
Write-Output "sauce.rdc.VodQaNativeAppApiKey stored in Azure DevOps=>$rdcVodQaNativeAppApiKey"
Write-Output "sauce.rdc.SauceDemoIosRdcApiKey stored in Azure DevOps=>$rdcSauceDemoIosRdcApiKey"

[Environment]::SetEnvironmentVariable("SAUCE_USERNAME", "$sauceUserName", "User")
[Environment]::SetEnvironmentVariable("SAUCE_ACCESS_KEY", "$sauceAccessKey", "User")
[Environment]::SetEnvironmentVariable("VODQC_RDC_API_KEY", "$rdcVodQaNativeAppApiKey", "User")
[Environment]::SetEnvironmentVariable("SAUCE_DEMO_IOS_RDC_API_KEY", "$rdcSauceDemoIosRdcApiKey", "User")

3. Create a Powershell task in your Pipeline

The Powershell script will read the values that are passed in from the Azure DevOps and then run those values through SetEnvironmentVariable() in the .ps1

When this task runs, I’m having it output the values to the Azure DevOps logs so that I can make sure the right values are being read. Here’s an example

ADO variables being read in the Posh script

How to read environment variables in Azure DevOps?

If you are reading an environment variable in your code like this

var sauceAccessKey = Environment.GetEnvironmentVariable("SAUCE_ACCESS_KEY");

Make sure that you do NOT set the EnvironmentVariableTarget.User as your 2nd parameter as Azure DevOps will not be able to read that variable.

How to create environment variables to share across pipelines

If you would like to reuse environment variables across multiple pipelines, then you need to use variable groups. It’s important to know that if use “group”, then you now need to list your other variables in a key/value pairs.

variables:
- group: sauce-labs-variables
- name: solution
  value: '**/*.sln'
- name: buildPlatform
  value: 'Any CPU'
- name: buildConfiguration
  value: 'Release'

How to package Nuget using Azure DevOps?

Phenomenal resource that will walk you through the process.

This is a resource that helps you to understand how to work with Nuget in .NET Standard.

Set up a Service connection to Nuget in your project settings

You do need to have an MSDN account and then you can create a Nuget.org account.

How to publish the Nuget package

  1. Download Nuget.exe
  2. Add a nuget.config file
  3. Run command nuget restore
  4. Run command .\nuget.exe push -Source "Simple.Sauce" -ApiKey az "C:\Source\SauceLabs\simple_sauce\dotnet\Simple.Sauce\bin\Debug\Simple.Sauce.0.1.1-debug.nupkg"

Why DevOps?

value of dev ops

value of dev-ops

Adding continuous integration

  1. Select Builds > Edit > Triggers. Under Continuous integration, select on the name of your repository.
    1. Toggle on the checkbox labeled Enable continuous integration.
    2. You can select CI for both merges and Pull Requests – https://prnt.sc/kb0g6n

How to create scheduled builds

  1. Picking up from the section above, click the Add button under Scheduled section
  2. Update the time and the day of when you want to run your builds
  3. Save & queue

How to set up your test .dll paths

Docs from MS on file matching patterns

The hardest time I had was how to configure my paths for my automation .DLL files. It’s not intuitive to know what is the working directory of your code base.

Here are some examples of what’s worked for me:

Executable Paths

"C:\Source\Github\dot-net-sauce\SauceExamples\Web.Tests\bin\Debug\Web.Tests.dll"'**\$(BuildConfiguration)\**\Web.Tests.dll'
"C:\Source\Github\dot-net-sauce\SauceExamples\SeleniumNunit\bin\Debug\SeleniumNunit.dll"'**\$(BuildConfiguration)\**\SeleniumNunit.dll'
Column A shows the local path. Column B shows how the path looks in Azure DevOps.

How to pass parameters to test code from a build or release pipeline?

A: Use a runsettings file to pass values as parameters to your test code. For example, in a release that contains several stages, you can pass the appropriate app URL to each the test tasks in each one. The runsettings file and matching parameters must be specified in the Visual Studio Test task.

Source

How to add a status badge to your Github repo

The instructions on this are really good from Microsoft and you can follow them here in the Get the status badge section

Finally, you want to have a powershell step in your YAML that executes this Powershell script and passes in the values from the variables that you set in the Azure DevOps UI.

Below is what my YAML step looks like and I’m basically setting the SAUCE_USERNAME and SAUCE_ACCCESSKEY variables.

In order for the YAML to understand where these variables come from, you need to convert sauce.userName to SAUCE_USERNAME. That’s the Azure convention. Read more about working with variables.

Basically the value stored in sauce.userName is passed in as a variable called $env:SAUCE_USERNAME . It’s the same exact variable, but when you convert it from the ADO UI to YAML, that’s the convention, I know, it’s weird…

sauce.AccessKey = $env:SAUCE_ACCESSKEY

word.a.b.c = WORD_A_B_C

powershell to set env variables

 

powershell to set env variables

All about YAML

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