Add configuration file for Cake.

[patriksvensson]

Sometimes we want to be able to configure internals of Cake so I propose that we add support for this. My proposal is that we add ICakeConfiguration that will fetch values in the following order:

1. Environment
2. Configuration file
3. Arguments

public interface ICakeConfiguration
{
  string GetValue(string key);
}

• Configuration keys are case insensitive.

Environment variables:

Environment variables are named like the following convention:

CAKE_[KEY]

The CAKE_ part will be completely removed from the key name.

Example

PS> $env:CAKE_RUNTESTS=true
PS> $env:CAKE_TOOLS_PATH=D:/tools

Configuration file:

; Cake configuration file

; Global settings
RunTests=true

[Tools]
Path=D:/tools

Arguments:

Arguments are passed in the following format:

--[key]=[value]

Example:

Cake.exe --tools_path=D:/tools --runtests=true

Using the configuration

public void DoMagic(ICakeConfiguration config)
{
  var runTests = config.Get("RunTests");
  var toolPath2 = config.Get("Tools_Path");
}

[RLittlesII]

@patriksvensson would there be a way for me to explicitly choose one of the configuration mechanisms? I can see myself attempting to send in configuration from a file unaware that someone has setup environment variables. Maybe on the -Verbosity diagnostic it can tell me which configuration is being respected.

[patriksvensson]

@RLittlesII Different ways of getting configuration values will have different precedence.

1. Arguments
2. Configuration file
3. Environment

So an environment variable can be overridden by a configuration file which in turn can be overridden by an argument.

[gitfool]

Nice. FWIW, sounds a lot like aspnet/Configuration.

[gep13]

@gitfool said...
Nice. FWIW, sounds a lot like aspnet/Configuration.

Thanks, we are aware of the potential cross over. However, since that package is still pre-release, and also due to the fact that we don't want to pull in another dependency for Cake at this time, we decided to roll our own for now.

[bspinner]

Shouldn't the config-file also be respected by the build.ps1 and build.sh scripts?

[patriksvensson]

No, the bootstrapper script are optional and more of a convenience thing. Each person will need to update their bootstrappers to fit their need.

[Meir017]

any plans on migrating to Microsoft.Extensions.Configuration? we could use their Ini provider

[devlead]

@Meir017 no, but you could probably reference it as an addin if you want to utilize it in your build scripts.

[gep13]

@Meir017 just to add a little more to this...

no, but you could probably reference it as an addin if you want to utilize it in your build scripts.

Cake has deliberately not taken dependencies on 3rd Party Libraries. This has aided us to continue to work seamlessly across all the target operating system and environments. Granted, libraries such as the one you mention are starting to work everywhere, but in all likelihood Cake will continue with the same premise, i.e. only take a dependency when there is literally no other way to achieve the desired outcome.

[khiemnd777]

How do i use the CakeConfigration in build.cake file?

[pitermarx]

I actually did exactly this manually. I have a JSON file with the defaults, then arguments override that and env vars override that. Would be nice to have it OOB

[pitermarx]

Is this already built-in?
https://cakebuild.net/docs/running-builds/configuration/set-configuration-values