From 17b8990cdb5e71752bed3570a20cbd4a68d6db89 Mon Sep 17 00:00:00 2001
From: Brice Dutheil <brice.dutheil@gmail.com>
Date: Wed, 16 Sep 2026 17:04:46 +0200
Subject: [PATCH] ci: use branch-isolated S3 Gradle cache

---
 .gitlab-ci.yml      | 16 ++--------------
 settings.gradle.kts | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 0e26911aa0b..a3066483bdc 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -55,8 +55,8 @@ variables:
   REGISTRY: 486234852809.dkr.ecr.us-east-1.amazonaws.com
   BUILD_JOB_NAME: "build"
   DEPENDENCY_CACHE_POLICY: pull
-  BUILD_CACHE_POLICY: pull
-  GRADLE_VERSION: "9.7.1" # must match gradle-wrapper.properties
+  S3_BUILD_CACHE_BUCKET: "dd-trace-java-gradle-build-cache"
+  S3_BUILD_CACHE_REGION: "us-east-1"
   MASS_READ_URL: "https://mass-read.us1.ddbuild.io"
   MAVEN_REPOSITORY_PROXY: "https://depot-read-api-java.us1.ddbuild.io/magicmirror/magicmirror/@current/"
   GRADLE_PLUGIN_PROXY: "https://depot-read-api-java.us1.ddbuild.io/magicmirror/magicmirror/@current/"
@@ -235,14 +235,6 @@ default:
       fallback_keys: # Use fallback keys because all cache types are not populated. See note under: populate_dep_cache
         - 'dependency-base'
         - 'dependency-lib'
-    - &build_cache
-      key: $CI_PIPELINE_ID-$CACHE_TYPE # Incremental build cache. Shared by all jobs in the pipeline of the same type
-      paths:
-        - .gradle/caches/$GRADLE_VERSION
-        - .gradle/$GRADLE_VERSION/executionHistory
-        - workspace
-      policy: $BUILD_CACHE_POLICY
-      unprotect: true
   before_script:
     - source .gitlab/gitlab-utils.sh
     - *container_info
@@ -349,7 +341,6 @@ build:
       optional: true
   extends: .gradle_build
   variables:
-    BUILD_CACHE_POLICY: push
     CACHE_TYPE: "lib"
     DEPENDENCY_CACHE_POLICY: pull
   script:
@@ -375,7 +366,6 @@ build_tests:
   extends: .gradle_build
   variables:
     <<: *tier_xl_variables
-    BUILD_CACHE_POLICY: push
     DEPENDENCY_CACHE_POLICY: pull
   parallel:
     matrix:
@@ -433,13 +423,11 @@ populate_dep_cache:
     - job: build_tests
       artifacts: false
   variables:
-    BUILD_CACHE_POLICY: pull
     DEPENDENCY_CACHE_POLICY: push
   cache:
     - <<: *plugin_cache
       policy: pull
     - *dependency_cache
-    - *build_cache
   rules:
     - if: '$POPULATE_CACHE'
       when: on_success
diff --git a/settings.gradle.kts b/settings.gradle.kts
index e557332879d..6a7bfc36616 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -32,11 +32,15 @@ pluginManagement {
 }
 
 plugins {
+  id("com.github.burrunan.s3-build-cache") version "1.9.9"
   id("com.gradle.develocity") version "4.5.0"
   id("org.gradle.toolchains.foojay-resolver-convention") version "1.0.0"
 }
 
 val isCI = providers.environmentVariable("CI")
+val isGitLabCI = providers.environmentVariable("GITLAB_CI")
+val isGitLabTag = providers.environmentVariable("CI_COMMIT_TAG")
+val gitLabRefSlug = providers.environmentVariable("CI_COMMIT_REF_SLUG")
 val skipBuildscan = providers.environmentVariable("SKIP_BUILDSCAN").map { it.toBoolean() }.orElse(false)
 
 develocity {
@@ -53,6 +57,17 @@ if (isCI.isPresent) {
     local {
       directory = File(rootDir, "workspace/build-cache")
     }
+    if (isGitLabCI.isPresent && !isGitLabTag.isPresent) {
+      remote<com.github.burrunan.s3cache.AwsS3BuildCache> {
+        region = providers.environmentVariable("S3_BUILD_CACHE_REGION").get()
+        bucket = providers.environmentVariable("S3_BUILD_CACHE_BUCKET").get()
+        prefix =
+          "trial/v1/${gitLabRefSlug.get()}/${System.getProperty("os.arch")}/"
+        isPush = true
+        lookupDefaultAwsCredentials = true
+        isReducedRedundancy = false
+      }
+    }
   }
 }