Gradle properties plugin

General

Gradle plugin that imports properties from external file (other than ./gradle.properties) into the project. The plugin support mandatory and optional properties and both project extra properties and system properties.

Usage

Gradle support two major property sets:

• Project properties (defined either by command-line, system properties, environment or ./gradle.properties file).
• Extra properties set (custom properties that may be added by various plugins and tasks).

To import to either sets, simply include the plugin in your Gradle build script and configure it:

// Kotlin DSL
plugins {
    id("com.nocwriter.gradle.props")
}

propertySources {
    // Load into project extra properties.
    required("./default.properties")
    optional("./local.properties")
    optional("./prod.properties")

    // Load into system properties.
    requiredSystemProperties("/.default_system_props.properties")
    optionalSystemProperties("/.production_sys_props.properties")
}

You can than easily access properties in various ways:

// Kotlin DSL

// Fetch 'sampleProp' property from project's extra property set.
val sampleProp: String by project.extra

// Fetch 'sampleSysProp' property from system properties set.
val sampleSysProp: String = property("sampleSysProp")

Requires and optional statements

Property files marked as required will cause failure if file does not exist. Optional files will be skipped if file does not exist.

Either mandatory (required) or optional files that does exist but cannot be read or parsed for some reason, will cause failure (by design).

Properties file format

This plugin supports standard properties file conventions:

# Comment line
key1=value
key2=value

Special usage notes

Properties are applied only after the propertySources { ... } block is evaluated. Trying to address properties prior to the sources blocks will fail.

Take a look at the following example (assuming default.properties contains a key named sampleProp):

// Kotlin DSL
plugins {
    id("com.nocwriter.gradle.props")
}

// Should fail, because 'default.properties' has not been loaded yet.
val sampleProp: String by project.extra

propertySources {
    required("default.properties")
}

// That's fine, because 'default.properties' already loaded into project's extra properties set.
val sampleProp: String by project.extra

Compatability

Plugin tested with Gradle versions 6.9.2 and 7.4.2 under OpenJDK 11.