fix(validator): accept newer AWS regions like eu-central-2

rusoto_core 0.48.0 (abandoned) hardcoded the set of known AWS regions
and rejected anything launched after its last release, surfacing as
"Not a valid AWS region: eu-central-2" when parsing the validator's
checkpointSyncer config or the relayer's S3 storage location URL.

aws_types::Region is an intentional pass-through newtype — the SDK
does not validate region strings because new regions launch regularly
and private partitions have non-public ones. A bogus region fails at
the first API call with a clear endpoint error, so no client-side
validation is needed. Drop the rusoto-based check and pass the string
straight through.

Author: paulbalaji

rust/main/agents/validator/src/settings.rs

@@ -293,12 +293,12 @@ fn parse_checkpoint_syncer(syncer: ValueParser) -> ConfigResult<CheckpointSyncer
                 .parse_string()
                 .end()
                 .map(str::to_owned);
-            // Using rusoto_core::Region just to get some input validation
-            let region: Option<rusoto_core::Region> = syncer
+            let region: Option<String> = syncer
                 .chain(&mut err)
                 .get_key("region")
-                .parse_from_str("Expected aws region")
-                .end();
+                .parse_string()
+                .end()
+                .map(str::to_owned);
             let folder = syncer
                 .chain(&mut err)
                 .get_opt_key("folder")
@@ -309,7 +309,7 @@ fn parse_checkpoint_syncer(syncer: ValueParser) -> ConfigResult<CheckpointSyncer
             cfg_unwrap_all!(&syncer.cwp, err: [bucket, region]);
             err.into_result(CheckpointSyncerConf::S3 {
                 bucket,
-                region: Region::new(region.name().to_owned()),
+                region: Region::new(region),
                 folder,
             })
         }

rust/main/hyperlane-base/src/settings/checkpoint_syncer.rs

@@ -2,7 +2,7 @@ use std::{env, path::PathBuf};
 
 use aws_config::Region;
 use core::str::FromStr;
-use eyre::{eyre, Context, Report, Result};
+use eyre::{eyre, Report, Result};
 use prometheus::IntGauge;
 use tracing::error;
 use ya_gcp::{AuthFlow, ServiceAccountAuth};
@@ -79,15 +79,7 @@ impl FromStr for CheckpointSyncerConf {
                 Ok(CheckpointSyncerConf::S3 {
                     bucket: bucket.into(),
                     folder,
-                    // Wildly, aws_config doesn't provide any client-side way to validate a region string, so while
-                    // we still have Rusoto around we just use that to validate the region string :)
-                    region: aws_config::Region::new(
-                        region
-                            .parse::<rusoto_core::Region>()
-                            .context("Invalid region when parsing storage location")?
-                            .name()
-                            .to_owned(),
-                    ),
+                    region: aws_config::Region::new(region.to_owned()),
                 })
             }
             "file" => Ok(CheckpointSyncerConf::LocalStorage {
@@ -290,4 +282,22 @@ mod test {
             _ => panic!("Expected a reorg event error"),
         }
     }
+
+    #[test]
+    fn test_parse_s3_storage_location_with_new_region() {
+        use super::*;
+        let conf = CheckpointSyncerConf::from_str("s3://my-bucket/eu-central-2/folder").unwrap();
+        match conf {
+            CheckpointSyncerConf::S3 {
+                bucket,
+                folder,
+                region,
+            } => {
+                assert_eq!(bucket, "my-bucket");
+                assert_eq!(folder.as_deref(), Some("folder"));
+                assert_eq!(region.as_ref(), "eu-central-2");
+            }
+            _ => panic!("Expected S3 checkpoint syncer"),
+        }
+    }
 }