NuGet : How can i apply transform to .csdef file of Cloud project
The nuget config transformations actually work on ANY XML file using the same *.transform convention (except for packages.config, for which there are other hacks/workarounds).
If you simply need to transform (read: add/merge changes into) the csdef file, this should work.
If not, you can attempt the PowerShell route and modify the target file using an XML template file embedded in your package. If you need inspiration on how to do so, you can find an example package which generates a certain XML file (actually a nuspec file) here:https://github.com/myget/NuGetPackages/blob/master/NuSpec/tools/init.ps1
Also, if the question still stands, could you please mention which version of nuget you are using?