fix: stop uploading empty placeholder cache tars to S3

The build workflow created empty tar files (via `tar --files-from /dev/null`)
as placeholders before remote-cli-post-build runs. When the container is
OOM-killed, only these ~10KB empty tars survive and get uploaded to S3.
On the next build, the pull-cache hook downloads them and extracts an empty
Library, providing zero caching benefit.

Changes:
- Remove empty placeholder tar creation in build-automation-workflow.ts
- Keep mkdir -p for cache directories (hooks need them)
- Add size check in aws-s3-upload-cache hook to delete tar files < 1KB
  before uploading, as a safety net against stale stubs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/orchestrator-integrity.yml

@@ -91,7 +91,7 @@ jobs:
             -e SERVICES=s3,cloudformation,ecs,kinesis,cloudwatch,logs,efs,ec2,iam,elasticfilesystem,secretsmanager,lambda,events,sts \
             -e DEBUG=0 \
             -e HOSTNAME_EXTERNAL=localstack-main \
-            localstack/localstack:latest || true
+            localstack/localstack:4.4.0 || true
           # Wait for LocalStack to be ready - check both health endpoint and S3 service
           echo "Waiting for LocalStack to be ready..."
           MAX_ATTEMPTS=60

dist/index.js

@@ -3398,7 +3398,7 @@ class AWSTaskRunner {
             return { name: x.name, value };
         });
     }
-    static async runTask(taskDef, environment, commands) {
+    static async runTask(taskDef, environment, secrets, commands) {
         const cluster = taskDef.baseResources?.find((x) => x.LogicalResourceId === 'ECSCluster')?.PhysicalResourceId || '';
         const taskDefinition = taskDef.taskDefResources?.find((x) => x.LogicalResourceId === 'TaskDefinition')?.PhysicalResourceId || '';
         const SubnetOne = taskDef.baseResources?.find((x) => x.LogicalResourceId === 'PublicSubnetOne')?.PhysicalResourceId || '';
@@ -3407,6 +3407,11 @@ class AWSTaskRunner {
         const streamName = taskDef.taskDefResources?.find((x) => x.LogicalResourceId === 'KinesisStream')?.PhysicalResourceId || '';
         // Transform localhost endpoints for container environment
         const transformedEnvironment = AWSTaskRunner.transformEndpointsForContainer(environment);
+        // Merge secrets into environment as plain env vars, matching docker and k8s provider behavior.
+        // This ensures UNITY_EMAIL, UNITY_PASSWORD, UNITY_SERIAL reach the container reliably
+        // without depending on CloudFormation Secrets Manager resolution.
+        const secretsAsEnvironment = secrets.map((s) => ({ name: s.EnvironmentVariable, value: s.ParameterValue }));
+        const mergedEnvironment = [...transformedEnvironment, ...secretsAsEnvironment];
         const runParameters = {
             cluster,
             taskDefinition,
@@ -3415,7 +3420,7 @@ class AWSTaskRunner {
                 containerOverrides: [
                     {
                         name: taskDef.taskDefStackName,
-                        environment: transformedEnvironment,
+                        environment: mergedEnvironment,
                         command: ['-c', command_hook_service_1.CommandHookService.ApplyHooksToCommands(commands, orchestrator_1.default.buildParameters)],
                     },
                 ],
@@ -4449,7 +4454,7 @@ class AWSBuildEnvironment {
         try {
             const postSetupStacksTimeMs = Date.now();
             orchestrator_logger_1.default.log(`Setup job time: ${Math.floor((postSetupStacksTimeMs - startTimeMs) / 1000)}s`);
-            const { output, shouldCleanup } = await aws_task_runner_1.default.runTask(taskDef, environment, commands);
+            const { output, shouldCleanup } = await aws_task_runner_1.default.runTask(taskDef, environment, secrets, commands);
             postRunTaskTimeMs = Date.now();
             orchestrator_logger_1.default.log(`Run job time: ${Math.floor((postRunTaskTimeMs - postSetupStacksTimeMs) / 1000)}s`);
             if (shouldCleanup) {
@@ -9414,6 +9419,10 @@ class ContainerHookService {
       fi
       ENDPOINT_ARGS=""
       if [ -n "$AWS_S3_ENDPOINT" ]; then ENDPOINT_ARGS="--endpoint-url $AWS_S3_ENDPOINT"; fi
+      # Skip uploading empty or near-empty tar files (< 1KB) — these are leftover
+      # stubs with no real cache data and would poison the cache for the next build.
+      find /data/cache/$CACHE_KEY/lfs -name "*.tar*" -size -1k -delete 2>/dev/null || true
+      find /data/cache/$CACHE_KEY/Library -name "*.tar*" -size -1k -delete 2>/dev/null || true
       aws $ENDPOINT_ARGS s3 cp --recursive /data/cache/$CACHE_KEY/lfs s3://${orchestrator_1.default.buildParameters.awsStackName}/orchestrator-cache/$CACHE_KEY/lfs || true
       rm -r /data/cache/$CACHE_KEY/lfs || true
       aws $ENDPOINT_ARGS s3 cp --recursive /data/cache/$CACHE_KEY/Library s3://${orchestrator_1.default.buildParameters.awsStackName}/orchestrator-cache/$CACHE_KEY/Library || true
@@ -9907,13 +9916,14 @@ echo "CACHE_KEY=$CACHE_KEY"`;
     if ! command -v yarn > /dev/null 2>&1; then printf '#!/bin/sh\nexit 0\n' > /usr/local/bin/yarn && chmod +x /usr/local/bin/yarn; fi
     # Pipe entrypoint.sh output through log stream to capture Unity build output (including "Build succeeded")
     { echo "game ci start"; echo "game ci start" >> /home/job-log.txt; echo "CACHE_KEY=$CACHE_KEY"; echo "$CACHE_KEY"; if [ -n "$LOCKED_WORKSPACE" ]; then echo "Retained Workspace: true"; fi; if [ -n "$LOCKED_WORKSPACE" ] && [ -d "$GITHUB_WORKSPACE/.git" ]; then echo "Retained Workspace Already Exists!"; fi; /entrypoint.sh; } | node ${builderPath} -m remote-cli-log-stream --logFile /home/job-log.txt
+    # Ensure cache directories exist for post-build and S3 upload hooks.
+    # Do NOT create empty placeholder tars — they waste S3 storage and on next
+    # build the pull-cache hook downloads them, giving Unity an empty Library
+    # (no caching benefit). The real tars are created by remote-cli-post-build
+    # via Caching.PushToCache(), and the S3 upload hooks use || true so missing
+    # files are handled gracefully.
     mkdir -p "/data/cache/$CACHE_KEY/Library"
-    if [ ! -f "/data/cache/$CACHE_KEY/Library/lib-$BUILD_GUID.tar" ] && [ ! -f "/data/cache/$CACHE_KEY/Library/lib-$BUILD_GUID.tar.lz4" ]; then
-      tar -cf "/data/cache/$CACHE_KEY/Library/lib-$BUILD_GUID.tar" --files-from /dev/null || touch "/data/cache/$CACHE_KEY/Library/lib-$BUILD_GUID.tar"
-    fi
-    if [ ! -f "/data/cache/$CACHE_KEY/build/build-$BUILD_GUID.tar" ] && [ ! -f "/data/cache/$CACHE_KEY/build/build-$BUILD_GUID.tar.lz4" ]; then
-      tar -cf "/data/cache/$CACHE_KEY/build/build-$BUILD_GUID.tar" --files-from /dev/null || touch "/data/cache/$CACHE_KEY/build/build-$BUILD_GUID.tar"
-    fi
+    mkdir -p "/data/cache/$CACHE_KEY/build"
     # Run post-build tasks and capture output
     # Note: Post-build may clean up the builder directory, so we write output directly to log file
     # Use set +e to allow the command to fail without exiting the script

src/model/orchestrator/providers/aws/aws-task-runner.ts

@@ -1,6 +1,7 @@
 import { DescribeTasksCommand, RunTaskCommand, waitUntilTasksRunning } from '@aws-sdk/client-ecs';
 import { DescribeStreamCommand, GetRecordsCommand, GetShardIteratorCommand } from '@aws-sdk/client-kinesis';
 import OrchestratorEnvironmentVariable from '../../options/orchestrator-environment-variable';
+import OrchestratorSecret from '../../options/orchestrator-secret';
 import * as core from '@actions/core';
 import OrchestratorAWSTaskDef from './orchestrator-aws-task-def';
 import * as zlib from 'node:zlib';
@@ -56,6 +57,7 @@ class AWSTaskRunner {
   static async runTask(
     taskDef: OrchestratorAWSTaskDef,
     environment: OrchestratorEnvironmentVariable[],
+    secrets: OrchestratorSecret[],
     commands: string,
   ): Promise<{ output: string; shouldCleanup: boolean }> {
     const cluster = taskDef.baseResources?.find((x) => x.LogicalResourceId === 'ECSCluster')?.PhysicalResourceId || '';
@@ -73,6 +75,12 @@ class AWSTaskRunner {
     // Transform localhost endpoints for container environment
     const transformedEnvironment = AWSTaskRunner.transformEndpointsForContainer(environment);
 
+    // Merge secrets into environment as plain env vars, matching docker and k8s provider behavior.
+    // This ensures UNITY_EMAIL, UNITY_PASSWORD, UNITY_SERIAL reach the container reliably
+    // without depending on CloudFormation Secrets Manager resolution.
+    const secretsAsEnvironment = secrets.map((s) => ({ name: s.EnvironmentVariable, value: s.ParameterValue }));
+    const mergedEnvironment = [...transformedEnvironment, ...secretsAsEnvironment];
+
     const runParameters = {
       cluster,
       taskDefinition,
@@ -81,7 +89,7 @@ class AWSTaskRunner {
         containerOverrides: [
           {
             name: taskDef.taskDefStackName,
-            environment: transformedEnvironment,
+            environment: mergedEnvironment,
             command: ['-c', CommandHookService.ApplyHooksToCommands(commands, Orchestrator.buildParameters)],
           },
         ],

src/model/orchestrator/providers/aws/index.ts

@@ -125,7 +125,7 @@ class AWSBuildEnvironment implements ProviderInterface {
     try {
       const postSetupStacksTimeMs = Date.now();
       OrchestratorLogger.log(`Setup job time: ${Math.floor((postSetupStacksTimeMs - startTimeMs) / 1000)}s`);
-      const { output, shouldCleanup } = await AwsTaskRunner.runTask(taskDef, environment, commands);
+      const { output, shouldCleanup } = await AwsTaskRunner.runTask(taskDef, environment, secrets, commands);
       postRunTaskTimeMs = Date.now();
       OrchestratorLogger.log(`Run job time: ${Math.floor((postRunTaskTimeMs - postSetupStacksTimeMs) / 1000)}s`);
       if (shouldCleanup) {

src/model/orchestrator/services/hooks/container-hook-service.ts

@@ -155,6 +155,10 @@ export class ContainerHookService {
       fi
       ENDPOINT_ARGS=""
       if [ -n "$AWS_S3_ENDPOINT" ]; then ENDPOINT_ARGS="--endpoint-url $AWS_S3_ENDPOINT"; fi
+      # Skip uploading empty or near-empty tar files (< 1KB) — these are leftover
+      # stubs with no real cache data and would poison the cache for the next build.
+      find /data/cache/$CACHE_KEY/lfs -name "*.tar*" -size -1k -delete 2>/dev/null || true
+      find /data/cache/$CACHE_KEY/Library -name "*.tar*" -size -1k -delete 2>/dev/null || true
       aws $ENDPOINT_ARGS s3 cp --recursive /data/cache/$CACHE_KEY/lfs s3://${
         Orchestrator.buildParameters.awsStackName
       }/orchestrator-cache/$CACHE_KEY/lfs || true

src/model/orchestrator/workflows/build-automation-workflow.ts

@@ -170,13 +170,14 @@ echo "CACHE_KEY=$CACHE_KEY"`;
     if ! command -v yarn > /dev/null 2>&1; then printf '#!/bin/sh\nexit 0\n' > /usr/local/bin/yarn && chmod +x /usr/local/bin/yarn; fi
     # Pipe entrypoint.sh output through log stream to capture Unity build output (including "Build succeeded")
     { echo "game ci start"; echo "game ci start" >> /home/job-log.txt; echo "CACHE_KEY=$CACHE_KEY"; echo "$CACHE_KEY"; if [ -n "$LOCKED_WORKSPACE" ]; then echo "Retained Workspace: true"; fi; if [ -n "$LOCKED_WORKSPACE" ] && [ -d "$GITHUB_WORKSPACE/.git" ]; then echo "Retained Workspace Already Exists!"; fi; /entrypoint.sh; } | node ${builderPath} -m remote-cli-log-stream --logFile /home/job-log.txt
+    # Ensure cache directories exist for post-build and S3 upload hooks.
+    # Do NOT create empty placeholder tars — they waste S3 storage and on next
+    # build the pull-cache hook downloads them, giving Unity an empty Library
+    # (no caching benefit). The real tars are created by remote-cli-post-build
+    # via Caching.PushToCache(), and the S3 upload hooks use || true so missing
+    # files are handled gracefully.
     mkdir -p "/data/cache/$CACHE_KEY/Library"
-    if [ ! -f "/data/cache/$CACHE_KEY/Library/lib-$BUILD_GUID.tar" ] && [ ! -f "/data/cache/$CACHE_KEY/Library/lib-$BUILD_GUID.tar.lz4" ]; then
-      tar -cf "/data/cache/$CACHE_KEY/Library/lib-$BUILD_GUID.tar" --files-from /dev/null || touch "/data/cache/$CACHE_KEY/Library/lib-$BUILD_GUID.tar"
-    fi
-    if [ ! -f "/data/cache/$CACHE_KEY/build/build-$BUILD_GUID.tar" ] && [ ! -f "/data/cache/$CACHE_KEY/build/build-$BUILD_GUID.tar.lz4" ]; then
-      tar -cf "/data/cache/$CACHE_KEY/build/build-$BUILD_GUID.tar" --files-from /dev/null || touch "/data/cache/$CACHE_KEY/build/build-$BUILD_GUID.tar"
-    fi
+    mkdir -p "/data/cache/$CACHE_KEY/build"
     # Run post-build tasks and capture output
     # Note: Post-build may clean up the builder directory, so we write output directly to log file
     # Use set +e to allow the command to fail without exiting the script