Azure Web App deploy: Web Deploy cannot modify the file on the destination because it is locked by an external process

Question

I am using the \"Azure Web App Deployment\" build step in VSTS to publish an ASP.NET Core API to an Azure Web App:

Occasionally, this step breaks with the f

Answer 1

I was getting the same error while I was trying to publish my Azure Function App. I followed this Microsoft document and did the following steps.

1. Right click on your Project and select Edit ....csproj

2. Add <EnableMSDeployAppOffline>true</EnableMSDeployAppOffline> in PropertyGroup tag

   <PropertyGroup>
     <TargetFramework>netcoreapp2.1</TargetFramework>
     <AzureFunctionsVersion>v2</AzureFunctionsVersion>
     <EnableMSDeployAppOffline>true</EnableMSDeployAppOffline>
   </PropertyGroup>
   

3. Save and Rebuild your solution

4. Now publish again

If that didn't work for you, you can always add MSDEPLOY_RENAME_LOCKED_FILES=1 as Mr. Ben mentioned in his answer, to your Application settings. You can do that from Visual Studio itself.

Hope it helps

Answer 2

Taking website offline while release should do the trick.

Answer 3

I was struggling with the same locking issue.
There are now a new Tasks (in Preview) that you can add for starting and stopping the App Service:

Add a stop task before deployment and a start task after the deployment.

This did the trick for me.

Answer 4

There are some dedicated tasks for asp.net core projects because the deployment process is a little bit different.
You can get those from the marketplace for free, check out DNX Tasks vsts marketplace
Hope that helps!!

Answer 5

Juste add

<EnableMSDeployAppOffline>true</EnableMSDeployAppOffline>

to your publish profile(.pubxml).

Answer 6

As per a separate thread in the Microsoft Github repo here, there's a hacky workaround where if you add the following key to the Azure Appsettings, it can help resolve the locked file deployment error:

MSDEPLOY_RENAME_LOCKED_FILES = 1

I'm not sure how long this appsetting hack will be supported, but it did help solve the issue for me personally.