How can I reference FakeLib.dll in a Fake.Deploy deployment script? - f#

Question

I'm trying to reference FakeLib.dll from my local Fake.Deploy installation in my deployment script but can't seem to find the correct path to use. I found that Environment.CurrentDirectory points to my Fake.Deploy installation, but just using
#r #"FakeLib.dll"
doesn't work:
Deploy messages
{
2015-05-12 09::22:50.413
2015-05-12 09::22:50.417
2015-05-12 09::22:50.417 Install.fsx(2,1): error FS0082: Could not resolve this reference. Could not locate the assembly "FakeLib.dll". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors. (Code=MSB3245)
2015-05-12 09::22:50.432
2015-05-12 09::22:50.432
2015-05-12 09::22:50.433 Install.fsx(2,1): error FS0084: Assembly reference 'FakeLib.dll' was not found or is invalid
}
Examples I found on the web suggest to deploy FAKE along with my application in the NuGet package and reference it like this:
#r #"tools\FAKE\tools\FakeLib.dll"
but this seems like overkill and an unnecessary reference.
Does anyone know what path to use to reference the local Fake.Deploy installation?

Answer 1

Just found the answer myself: the base directory used for references in the post-deployment fsx script is __SOURCE_DIRECTORY__, the directory of the deployment itself.
So assuming your Fake.Deploy is installed in
.\Fake.Deploy\
then Environment.CurrentDirectory will point to this directory, whereas __SOURCE_DIRECTORY__ will point to
.\Fake.Deploy\deployments\\{your_app}\active
So you can reference FakeLib.dll from your post-deployment fsx script as follows:
#r #"..\..\..\FakeLib.dll"
I will try to get this added to the documentation page.
That being said, there are in fact points to be made for deploying FAKE together with your application:
It makes sure the correct version is used to run your deployment script
The Fake.Deploy installation might not be be under your control, so you could be prevented permission-wise from accessing its binaries
The configuration of Fake.Deploy allows to specify a different deplyoment location (via "WorkDirectory"), so this hardcoded path will break when using a non-default location

Answer 2

Note that when your NuGet package is sent over via Fake.Deploy, the agent runs the script in the root of the package from the same folder as the fake executable. So, when your fake.exe is in C:\Fake\tools\fake.exe, your files are in C:\Fake\tools\deployments\YourApplication\active. If you need to read a properties file or something from that directory, your script won't see it. So, you'll need to do the following in your script:
open System
open System.IO
let arguments = System.Environment.GetCommandLineArgs()
let script = arguments.[1]
let scriptDirectory = script.Replace(#"\NameOfMyDeployScript.fsx", #"")
System.IO.Directory.SetCurrentDirectory(scriptDirectory)
I wanted to put that out there so no one loses their mind over trying to access some file. You'll see an error like this if you don't change directories:
System.IO.FileNotFoundException: Could not find file 'C:\Fake\tools\myfile.properties'