Wednesday, 4 May 2016

Deploying Azure websites and webjobs using your CI system with msbuild and azure powershell cmdlets

There are lots of tutorials detailing how to send web apps and web jobs up to azure as part of your CI pipeline but I've found them all lacking, mainly in that they require you to upload to Azure in the same command as performing your build.
Often this command looks like the following:
msbuild.exe foobar.csproj /p:DeployOnBuild=true /p:PublishProfile="azurePubProfile" /p:Configuration=Release
This simultaneously builds, configures and publishes the project to azure.
This is unacceptable to me as I want to promote the same built artifact through many environments ci-test-preprod-prod where the only thing to change is the config getting deployed to each. I don't want to keep building the code over and over when I deploy which has many issues ranging from changes in the code between deployments to changes in the environment of the build machine. I want to know that what is getting deployed to prod is exactly the same binaries as was deployed and tested in all previous environments. To achieve this we need to separate the building of the artifact from the deployment.

What follows is the method we are now using to build and deploy our services to Azure. It breaks down into 4 simple steps
  1. Build your solution, firstly restoring any nuget packages if needed
  2. Configure your service for the target environment and zip up the artifact
  3. Configure the powershell session for azure
  4. Publish the zipped artifact to azure

App service (websites)


Firstly build your solution, if using any nuget packages restore these first
nuget restore
Perform the build on the solution
msbuild foobar.sln /t:build /p:configuration=release /p:OutDir=BUILD_OUTPUT_PATH
Grab the published website from ./foobar/BUILD_OUTPUT_PATH/_PublishedWebsites/foobar and safe it to your artifact store of choice.


Firstly apply the correct config for your target environment for this deployment to the artifact saved from the build. there are many ways to do this so i wont go in to it here.

Next zip up the deployable artifact
Add-Type -Assembly System.IO.Compression.FileSystem
$compressionLevel = [System.IO.Compression.CompressionLevel]::Optimal
[System.IO.Compression.ZipFile]::CreateFromDirectory($sourcedir, $zipfilename, $compressionLevel, $false)

Prepare the powershell session for the upload to azure
Load in your azure cert
Import-AzurePublishSettingsFile azure-credentials.publishsettings
Select the desired subscription
Select-AzureSubscription 00000000-0000-0000-0000-000000000001
Publish the website using the azure cmdlet
Publish-AzureWebsiteProject -Package -Name foobar -Slot 'staging'


As above except the location of the built artifact foobarjob/BUILD_OUTPUT_PATH
And the cmdlet for creating the webjob
New-AzureWebsiteJob -Name foobar -JobName foobarjob -JobType Continuous -JobFile .\


It turns out its actually really easy to achieve the result we desired, mainly the repeatable deployment of a known, tested build artifact to any environment we like.

We use GoCd from thoughtworks to orchestrate the above process through the pipelines feature. When all this is combined with staging slots, blue green deployments and the like you get a really robust process, excellent auditability, a solid rollback strategy and not to mention peace of mind when pushing to prod.

Id love to hear how you achieve the same results, whether its through version control strategies, azure deployment slot strategies or something else.
Let me know.

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