From f8caf6562fea44db752edaf91f00ce6fb6986928 Mon Sep 17 00:00:00 2001
From: u228298 <merlin.unterfinger@sbb.ch>
Date: Thu, 28 Aug 2025 11:04:51 +0200
Subject: [PATCH] feat(app): add support for S3-compatible services

- Extends the S3 client configuration to allow for endpoint overrides and path-style access, enabling the use of S3-compatible object storage solutions like MinIO.
- Enhances flexibility and allows the application to run in various environments outside of AWS. Configuration is managed via the standard `AWS_ENDPOINT_URL_S3` and `AWS_S3_FORCE_PATH_STYLE` environment variables.
- The deprecated `DefaultCredentialsProvider.create()` has been updated to its modern builder equivalent for safer credential management.
---
 .../app/infrastructure/GtfsScheduleS3.java    | 38 ++++++++++++++++++-
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/app/src/main/java/org/naviqore/app/infrastructure/GtfsScheduleS3.java b/app/src/main/java/org/naviqore/app/infrastructure/GtfsScheduleS3.java
index e26a3c01..5a7679e6 100644
--- a/app/src/main/java/org/naviqore/app/infrastructure/GtfsScheduleS3.java
+++ b/app/src/main/java/org/naviqore/app/infrastructure/GtfsScheduleS3.java
@@ -7,7 +7,9 @@
 import org.naviqore.service.repo.GtfsScheduleRepository;
 import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider;
 import software.amazon.awssdk.core.sync.ResponseTransformer;
+import software.amazon.awssdk.regions.Region;
 import software.amazon.awssdk.services.s3.S3Client;
+import software.amazon.awssdk.services.s3.S3ClientBuilder;
 import software.amazon.awssdk.services.s3.model.GetObjectRequest;
 
 import java.io.IOException;
@@ -19,12 +21,17 @@
  * Repository for loading a static GTFS feed from an S3 bucket.
  * <p>
  * Expected format for the S3 URI: {@code s3://bucket-name/path/to/gtfs.zip}. AWS credentials and region must be
- * provided via environment variables: {@code AWS_ACCESS_KEY_ID}, {@code AWS_SECRET_ACCESS_KEY}, {@code AWS_REGION}.
+ * provided via standard environment variables. Supports S3-compatible endpoints like MinIO via
+ * {@code AWS_ENDPOINT_URL_S3} and {@code AWS_S3_FORCE_PATH_STYLE}.
  */
 @Slf4j
 @RequiredArgsConstructor
 public class GtfsScheduleS3 implements GtfsScheduleRepository {
 
+    private static final String AWS_REGION = "AWS_REGION";
+    private static final String AWS_ENDPOINT_URL = "AWS_ENDPOINT_URL";
+    private static final String AWS_ENDPOINT_URL_S_3 = "AWS_ENDPOINT_URL_S3";
+    private static final String AWS_S_3_FORCE_PATH_STYLE = "AWS_S3_FORCE_PATH_STYLE";
     private static final String TMP_DIRECTORY_PREFIX = "tmp_gtfs_";
     private static final String FILE_NAME = "gtfs.zip";
 
@@ -39,13 +46,40 @@ public GtfsSchedule get() throws IOException, InterruptedException {
         Path tempDir = Files.createTempDirectory(TMP_DIRECTORY_PREFIX);
         Path filePath = tempDir.resolve(FILE_NAME);
 
-        try (S3Client s3 = S3Client.builder().credentialsProvider(DefaultCredentialsProvider.create()).build()) {
+        // setup default builder
+        S3ClientBuilder s3ClientBuilder = S3Client.builder()
+                .credentialsProvider(DefaultCredentialsProvider.builder().build());
 
+        // configure region from environment variable
+        String region = System.getenv(AWS_REGION);
+        if (region != null && !region.isBlank()) {
+            s3ClientBuilder.region(Region.of(region));
+        }
+
+        // configure endpoint override; use the S3-specific variable first, then fall back to the generic one
+        String endpointOverride = System.getenv(AWS_ENDPOINT_URL_S_3);
+        if (endpointOverride == null || endpointOverride.isBlank()) {
+            endpointOverride = System.getenv(AWS_ENDPOINT_URL);
+        }
+        if (endpointOverride != null && !endpointOverride.isBlank()) {
+            log.debug("S3 endpoint override is set to: {}", endpointOverride);
+            s3ClientBuilder.endpointOverride(URI.create(endpointOverride));
+        }
+
+        // force path-style access if requested
+        String forcePathStyle = System.getenv(AWS_S_3_FORCE_PATH_STYLE);
+        if ("true".equalsIgnoreCase(forcePathStyle)) {
+            log.info("S3 path-style access is enabled.");
+            s3ClientBuilder.forcePathStyle(true);
+        }
+
+        try (S3Client s3 = s3ClientBuilder.build()) {
             log.info("Downloading file: {}", s3Uri);
             s3.getObject(GetObjectRequest.builder().bucket(bucket).key(key).build(),
                     ResponseTransformer.toFile(filePath));
 
             return new GtfsScheduleReader().read(filePath.toString());
+
         } finally {
             Files.deleteIfExists(filePath);
             Files.deleteIfExists(tempDir);