Gradle: document supported project properties.

Author: greenrobot-team

.gitlab-ci.yml

@@ -5,8 +5,7 @@ image: objectboxio/buildenv:21.11.11-centos7
 # - SONATYPE_USER
 # - SONATYPE_PWD
 # - GOOGLE_CHAT_WEBHOOK_JAVA_CI
-# Additionally, Gradle scripts assume these Gradle project properties are set:
-# https://docs.gradle.org/current/userguide/build_environment.html#sec:project_properties
+# Additionally, these environment variables used by the objectbox-publish Gradle script:
 # - ORG_GRADLE_PROJECT_signingKeyFile
 # - ORG_GRADLE_PROJECT_signingKeyId
 # - ORG_GRADLE_PROJECT_signingPassword

build.gradle.kts

@@ -1,3 +1,10 @@
+// This script supports some Gradle project properties:
+// https://docs.gradle.org/current/userguide/build_environment.html#sec:project_properties
+// - versionPostFix: appended to snapshot version number, e.g. "1.2.3-<versionPostFix>-SNAPSHOT".
+//   Use to create different versions based on branch/tag.
+// - sonatypeUsername: Maven Central credential used by Nexus publishing.
+// - sonatypePassword: Maven Central credential used by Nexus publishing.
+
 buildscript {
     // Typically, only edit those two:
     val objectboxVersionNumber = "3.4.1" // without "-SNAPSHOT", e.g. "2.5.0" or "2.4.0-RC"

buildSrc/src/main/kotlin/objectbox-publish.gradle.kts

@@ -1,3 +1,17 @@
+// This script requires some Gradle project properties to be set
+// (to set as environment variable prefix with ORG_GRADLE_PROJECT_):
+// https://docs.gradle.org/current/userguide/build_environment.html#sec:project_properties
+//
+// To publish artifacts to the internal GitLab repo set:
+// - gitlabUrl
+// - gitlabPrivateToken
+// - gitlabTokenName: optional, if set used instead of "Private-Token". Use for CI to specify e.g. "Job-Token".
+//
+// To sign artifacts using an ASCII encoded PGP key given via a file set:
+// - signingKeyFile
+// - signingKeyId
+// - signingPassword
+
 plugins {
     id("maven-publish")
     id("signing")
@@ -73,6 +87,8 @@ publishing {
 
 signing {
     if (hasSigningProperties()) {
+        // Sign using an ASCII-armored key read from a file
+        // https://docs.gradle.org/current/userguide/signing_plugin.html#using_in_memory_ascii_armored_openpgp_subkeys
         val signingKey = File(project.property("signingKeyFile").toString()).readText()
         useInMemoryPgpKeys(
             project.property("signingKeyId").toString(),