web:WebApp kind drift not detected by refresh/preview

[andrej98]

What happened?

In pulumi UP, I tried to replace a windows code azureNative.web.WebApp with linux container azureNative.web.WebApp.
~ kind : "functionapp" => "functionapp,linux,container"
It went through and was replaced successfully.

The webApp has also a webAppSlot associated with it, and the replace on this slot failed with error:

error: Status=400 Message="{"Code":"BadRequest","Message":"The slot 'kind' property 'functionapp,linux,container' must match the Production site 'kind' property 'functionapp,linux'.","Target":null,"Details":[{"Message":"The slot 'kind' property 'functionapp,linux,container' must match the Production site 'kind' property 'functionapp,linux'."},{"Code":"BadRequest"},{"ErrorEntity":{"ExtendedCode":"54026","MessageTemplate":"The slot 'kind' property '{0}' must match the Production site 'kind' property '{1}'.","Parameters":["functionapp,linux,container","functionapp,linux"],"Code":"BadRequest","Message":"The slot 'kind' property 'functionapp,linux,container' must match the Production site 'kind' property 'functionapp,linux'."}}],"Innererror":null}"

After investigation I found out that the webApp had property kind: 'functionapp,linux' instead of 'functionapp,linux,container'. That might be either pulumi or Azure bug.

Another problem was that even though in Azure the kind was 'functionapp,linux', the refresh and subsequent preview showed no changes, even though the code had 'functionapp,linux,container'. I checked pulumi state and there was 'functionapp,linux,container', and the refresh was not updating it to correspond with the web app in Azure.

Version: pulumi-azure-native v3.19.0

Example

Replace windows code azureNative.web.WebApp with linux container azureNative.web.WebApp and observe the kind property.

Output of pulumi about

CLI
2026-06-26T11:06:12.1878317Z Version 3.248.0
2026-06-26T11:06:12.1878509Z Go Version go1.26.4
2026-06-26T11:06:12.1878684Z Go Compiler gc
2026-06-26T11:06:12.1878759Z
2026-06-26T11:06:12.1882287Z Host
2026-06-26T11:06:12.1882651Z OS ubuntu
2026-06-26T11:06:12.1882877Z Version 24.04
2026-06-26T11:06:12.1883044Z Arch x86_64
2026-06-26T11:06:12.1883119Z
2026-06-26T11:06:12.1891446Z Environment Variables:
2026-06-26T11:06:12.1893626Z Name Value
2026-06-26T11:06:12.1893991Z PULUMI_EXPERIMENTAL true
2026-06-26T11:06:12.1894352Z PULUMI_HOME "/mnt/vss/_work/_temp/1782471962013"
2026-06-26T11:06:12.1894725Z PULUMI_SKIP_CHECKPOINTS true

Additional context

No response

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