将DLL移动到Azure Cloud Service部署包

Question

Is there solid, no-fuss way to copy a file to an Azure cloud service deployment package without including or referencing it in the web project?

We have a site that we will be hosting both as a web role in an Azure cloud service project and on-premises, each requiring different libraries for the data access layer. We could dump all the necessary files into the project and have them copied on build and then dynamically select which assemblies to load based on environmental variables, but that seems a little sloppy--and there may be legitimate reasons why we wouldn't want those libraries sitting on a server in a distant Azure region. These assemblies are not referenced directly by the project, but are loaded at runtime using MEF or some similar mechanism.

Here's a post-build script that we've tried:

if "$(TargetProfile)" == "" (
     echo "OnPrem"
     xcopy /Y "$(ProjectDir)\lib\OnPrem\TestLibrary.dll" "$(ProjectDir)\$(OutputPath)\$(Configuration)"

) else (
     echo "Cloud"
     copy /Y "$(ProjectDir)\lib\Cloud\TestLibrary.dll" "$(ProjectDir)\$(OutputPath)\$(Configuration)"
)

This works, in as much as the file is copied as expected upon building and during the portion of the msbuild /t:publish step that builds the website project. However, the TestLibrary.dll file is not included in the cloud service package, not deployed, and fails to load at runtime.

Has something like this been done before with Azure deployments? I will concede that it's possible we are approaching this the wrong way, but I haven't yet discovered an elegant approach the fits our needs.

Answer 1

After playing around with this for some time, I think I've found a strategy that achieves more or less what I want. You can add content files to the CloudService Role that are packaged and deployed along with the cloud service like so:

1. In Visual Studio, right click the WebRole inside the CloudService project and select "Add Existing Item"
2. Browse and select the .dll you wish to add.
3. You may even create folders and such to organize these files.

These files are added to the approot in the .cspkg, and similarly end up in the approot folder when deployed. To resolve this directory I did this:

string appRoot = Environment.GetEnvironmentVariable("RoleRoot");
appRoot = Path.Combine(appRoot + @"\", @"approot\");

You'll still need a way to copy the on-premises .dlls for on-premises deployments, but we already have a method of doing that in our existing deployment process. Using configuration setting in CloudConfigurationManager you can tell the app how to resolve the directory where these .dlls ought to reside, eg:

    var libDir = CloudConfigurationManager.GetSetting("Environment").Equals("Cloud") 
        ?
        Environment.GetEnvironmentVariable("RoleRoot")
            .Path.Combine(appRoot + @"\", @"approot\")
        :
        HostingEnvironment.MapPath("~\pathToOnPremDlls\")

It feels vaguely hack-ish, but it seems to work well enough.