Gradle - GCSBuildCache

This Gradle plugin provides a build cache implementation that uses Google Cloud Storage to store build artifacts.

Options

The build cache takes the following options:

Option	Description
credentials	JSON key file of the service account to use, otherwise GCP Application Default Credentials are used. (optional)
bucket	Name of the Google Cloud Storage bucket (required)
refreshAfterSeconds	Amount of time to wait before the timestamp of a cached artifact that is still in use will be renewed (optional)
writeThreshold	Number of bytes at which the plugin starts using a file as a buffer for writing cache entries - default 8 MiB (optional)

Usage

There are multiple ways to use the Google Cloud Storage based build cache inside your projects.

As plugin in settings.gradle

settings.gradle

buildscript {
    repositories {
        maven {
            url 'https://plugins.gradle.org/m2/'
        }
    }

    dependencies {
        classpath 'net.idlestate:gradle-gcs-build-cache:1.2.2'
    }
}

apply plugin: 'net.idlestate.gradle-gcs-build-cache'

buildCache {
    local {
        enabled = false
    }

    remote( GCSBuildCache.class ) {
        credentials = 'my-key.json' // (optional)
        bucket = 'my-bucket'
        refreshAfterSeconds = 86400 // 24h (optional)
        writeThreshold = 8 * 1024 * 1024 // 8 MiB
        enabled = true
        push = true
    }
}

Manual registration in settings.gradle

settings.gradle

buildscript {
    repositories {
        maven {
            url 'https://plugins.gradle.org/m2/'
        }
    }

    dependencies {
        classpath 'net.idlestate:gradle-gcs-build-cache:1.2.2'
    }
}

import net.idlestate.gradle.caching.GCSBuildCache
import net.idlestate.gradle.caching.GCSBuildCacheServiceFactory

buildCache {
    local {
        enabled = false
    }

    registerBuildCacheService( GCSBuildCache.class, GCSBuildCacheServiceFactory.class )

    remote( GCSBuildCache.class ) {
        credentials = 'my-key.json' // (optional)
        bucket = 'my-bucket'
        refreshAfterSeconds = 86400 // 24h (optional)
        writeThreshold = 8 * 1024 * 1024 // 8 MiB
        enabled = true
        push = true
    }
}

Using an init script

init-build-cache.gradle

initscript {
    repositories {
        maven {
            url 'https://plugins.gradle.org/m2/'
        }
    }

    dependencies {
        classpath 'net.idlestate:gradle-gcs-build-cache:1.2.2'
    }
}

import net.idlestate.gradle.caching.GCSBuildCache
import net.idlestate.gradle.caching.GCSBuildCacheServiceFactory

gradle.settingsEvaluated { settings ->
    settings.buildCache {
        local {
            enabled = false
        }

        registerBuildCacheService( GCSBuildCache.class, GCSBuildCacheServiceFactory.class )

        remote( GCSBuildCache.class ) {
            credentials = 'my-key.json' // (optional)
            bucket = 'my-bucket'
            refreshAfterSeconds = 86400 // 24h (optional)
            writeThreshold = 8 * 1024 * 1024 // 8 MiB
            enabled = true
            push = true
        }
    }
}

% ./gradlew --build-cache --init-script init-build-cache.gradle <task>

Preparation in Google Cloud Storage

The following steps will create a Google Cloud Storage bucket named $BUCKET as part of the GCP project $PROJECT in your $REGION with private access. gsutil is available as part of the Google Cloud SDK.

% gsutil mb -p $PROJECT -c regional -l $REGION gs://$BUCKET
[...]
% gsutil acl set private gs://$BUCKET
[...]

To create a service account $ACCOUNT with access to the bucket the following commands have to be executed.

% gcloud iam service-accounts create $ACCOUNT --display-name "Service account to access the Gradle build cache in Google Cloud Storage"
[...]
% gsutil acl ch -u $ACCOUNT@$PROJECT.iam.gserviceaccount.com:WRITE gs://$BUCKET
[...]

A JSON key file $KEY_FILE that could be used by the Gradle plugin to access the bucket is created with the following statement.

% gcloud iam service-accounts keys create $KEY_FILE --iam-account $ACCOUNT@$PROJECT.iam.gserviceaccount.com
[...]

If cached artifacts should be deleted after two weeks lifecycle rules like the following should be applied to the bucket.

rules.json

{
  "rule":
  [
{
  "action": {"type": "Delete"},
  "condition": {"age": 14}
}
  ]
}

% gsutil lifecycle set rules.json gs://$BUCKET
[...]

License

LICENSE