Gradle global build directory

Question

I want to know is it possible to configure Gradle to use one global build directory for all projects? I need this because I store all my projects in Google Drive folder (for backup and fast access from other devices) and when I build project Google Drive is loading CPU while syncing project build directory. So I want to move build directories outside of Google Drive.

Also this option will be useful for those who want to build projects using RAM disk as storage for build directory.

Answer 1

Thanks to Peter Niederwieser. I decided to post my own answer because of additional details.

To setup global build directory you need to add these lines to ~/.gradle/init.gradle:

gradle.projectsLoaded {
    rootProject.allprojects {
        buildDir = "/path/to/build/${rootProject.name}/${project.name}"
    }
}

Nice option to have global build directory on the RAM disk.

If you are macOS (OS X) user you can do this with:

diskutil erasevolume HFS+ 'RAMDiskName' `hdiutil attach -nomount ram://XXXXXX`

where XXXXXX is a count of 512-byte blocks (for example, it's 262114 for 128MB RAM disk)

And buildDir line will be:

buildDir = "/Volumes/RAMDiskName/${rootProject.name}/${project.name}"

Also you can extend configuration to:

1. get global build path from environment variable or fallback to build directory inside project directory;
2. include project group in path, this makes path more unique especially if you have several projects with the same name.

~/.gradle/init.gradle:

def configProject(p, buildDir) {
    p.buildDir = "${buildDir}/${p.name}"  
    p.subprojects { s ->
        configProject(s, "${p.buildDir}")
    }
}

def buildDir = System.env.GRADLE_GLOBAL_BUILD_PATH
if (!buildDir?.trim()) {
    buildDir = "build"
}

gradle.projectsLoaded {
    if (ext.has("group")) {
        buildDir += "/${ext.group}"
    }
    configProject(rootProject, buildDir)
}

And in project settings.gradle:

gradle.ext.group = 'com.example.yourproject'

Also you can use this setting in project build.gradle to set project group but this is optional:

allprojects {
    ...
    group gradle.ext.group
}

Answer 2

build.gradle:

def baseDir = "/global/build/dir/$project.name"
buildDir = baseDir + "/root"
subprojects {
    buildDir = baseDir + project.path.replaceFirst(":", "/").replace(":", ".")
}

Answer 3

You could also go the opposite way. Replace the build folder with a global folder.

1. Remove project's build folder
2. mklink /d ...disk\path\to\project\build ...RAM\path\to\project (or ln in Unix)
3. Build fast

You can automate this in the clean task, so a gradlew clean cleans the folder contents and recreates the link.

With some quick testing it seems that Google Drive doesn't recognize directory in junction links on Windows. It'll sync the folders, but not the contents. Weirdly if I upload files to Drive into those folders, they're synced into the local copy. But, if I delete the synced file from the disk, the deletion is not synced back. It seems links cause Drive to be one way.