fix(admin): use madmin key names in list-remote-targets response

The admin list-remote-targets response serialized five fields under the
persisted snake_case keys (bandwidth_limit, storage_class, reset_id,
deployment_id, credentials.session_token), which madmin/mc decode to zero
values, blanking the bandwidth and reset-id columns of mc replicate ls.
Rename them to the madmin JSON tags (bandwidth, storageclass, resetID,
deploymentID, sessionToken) in remote_target_admin_json only, following
the existing Go-duration overwrite precedent there.

Symmetrically, BucketTarget deserialization only aliased bandwidth, so a
MinIO-written bucket-targets.json silently dropped the other four fields
to defaults on migration; add serde aliases for them. Aliases and the
response-layer rename leave the persisted bucket-targets.json and the
msgpack struct-map wire format untouched, pinned by new tests.

Refs rustfs/backlog#1951, spec rustfs/backlog#1946.

crates/ecstore/src/bucket/target/bucket_target.rs

@@ -32,6 +32,10 @@ pub struct Credentials {
     pub access_key: String,
     #[serde(rename = "secretKey")]
     pub secret_key: String,
+    // The aliases accept madmin's JSON tags (MinIO-written bucket-targets
+    // metadata and mc request bodies) without changing the snake_case
+    // persisted/peer wire format this struct serializes to.
+    #[serde(alias = "sessionToken")]
     pub session_token: Option<String>,
     pub expiration: Option<Timestamp>,
 }
@@ -207,7 +211,7 @@ pub struct BucketTarget {
 
     #[serde(rename = "replicationSync", default)]
     pub replication_sync: bool,
-    #[serde(default)]
+    #[serde(alias = "storageclass", default)]
     pub storage_class: String,
     #[serde(rename = "skipTlsVerify", default)]
     pub skip_tls_verify: bool,
@@ -220,7 +224,7 @@ pub struct BucketTarget {
 
     #[serde(rename = "resetBeforeDate", with = "time::serde::rfc3339::option", default)]
     pub reset_before_date: Option<OffsetDateTime>,
-    #[serde(default)]
+    #[serde(alias = "resetID", default)]
     pub reset_id: String,
     #[serde(rename = "totalDowntime", with = "duration_seconds", default)]
     pub total_downtime: Duration,
@@ -233,7 +237,7 @@ pub struct BucketTarget {
     #[serde(default)]
     pub latency: LatencyStat,
 
-    #[serde(default)]
+    #[serde(alias = "deploymentID", default)]
     pub deployment_id: String,
 
     #[serde(default)]
@@ -531,6 +535,84 @@ mod tests {
         assert_eq!(value["totalDowntime"], 90);
     }
 
+    #[test]
+    fn bucket_target_persisted_wire_keys_stay_snake_case() {
+        // bucket-targets.json (persisted via `serde_json::to_vec(&BucketTargets)`
+        // in the admin set/remove handlers) and the msgpack struct-map form
+        // (`BucketTargets::marshal_msg`) both come straight from this struct's
+        // serde field names. madmin naming is applied only in the admin
+        // response layer (`remote_target_admin_json`); renaming here would
+        // silently break every existing deployment's persisted metadata.
+        let targets = BucketTargets {
+            targets: vec![BucketTarget {
+                credentials: Some(Credentials {
+                    access_key: "ak".to_string(),
+                    secret_key: "sk".to_string(),
+                    session_token: Some("token".to_string()),
+                    expiration: None,
+                }),
+                bandwidth_limit: 5,
+                storage_class: "STANDARD".to_string(),
+                reset_id: "reset-1".to_string(),
+                deployment_id: "deploy-1".to_string(),
+                ..Default::default()
+            }],
+        };
+
+        let json = serde_json::to_value(&targets).expect("targets should serialize to JSON");
+        let msgpack: serde_json::Value =
+            rmp_serde::from_slice(&targets.marshal_msg().expect("targets should marshal to msgpack"))
+                .expect("msgpack struct map should decode into a JSON value");
+
+        for (wire, entry) in [("JSON", &json["targets"][0]), ("msgpack", &msgpack["targets"][0])] {
+            assert_eq!(entry["bandwidth_limit"], 5, "{wire} key `bandwidth_limit` must stay");
+            assert_eq!(entry["storage_class"], "STANDARD", "{wire} key `storage_class` must stay");
+            assert_eq!(entry["reset_id"], "reset-1", "{wire} key `reset_id` must stay");
+            assert_eq!(entry["deployment_id"], "deploy-1", "{wire} key `deployment_id` must stay");
+            assert_eq!(entry["credentials"]["session_token"], "token", "{wire} key `session_token` must stay");
+        }
+    }
+
+    #[test]
+    fn minio_written_bucket_targets_json_populates_madmin_named_fields() {
+        // A MinIO-written bucket-targets.json carries madmin's JSON tags
+        // (`bandwidth`, `storageclass`, `resetID`, `deploymentID`,
+        // `credentials.sessionToken`). On migration these must land in the
+        // matching fields instead of silently defaulting (backlog#1946).
+        let targets: BucketTargets = serde_json::from_value(serde_json::json!({
+            "targets": [{
+                "sourcebucket": "src",
+                "endpoint": "minio.example:9000",
+                "credentials": {
+                    "accessKey": "ak",
+                    "secretKey": "sk",
+                    "sessionToken": "minio-session-token"
+                },
+                "targetbucket": "dst",
+                "type": "replication",
+                "replicationSync": true,
+                "bandwidth": 107374182400i64,
+                "storageclass": "STANDARD",
+                "resetID": "reset-789",
+                "deploymentID": "deploy-123"
+            }]
+        }))
+        .expect("MinIO-written bucket-targets.json must deserialize");
+
+        let target = &targets.targets[0];
+        assert_eq!(target.bandwidth_limit, 107374182400);
+        assert_eq!(target.storage_class, "STANDARD");
+        assert_eq!(target.reset_id, "reset-789");
+        assert_eq!(target.deployment_id, "deploy-123");
+        assert_eq!(
+            target
+                .credentials
+                .as_ref()
+                .and_then(|credentials| credentials.session_token.as_deref()),
+            Some("minio-session-token")
+        );
+    }
+
     #[test]
     fn test_bucket_target_debug_redacts_credentials() {
         let target = BucketTarget {

rustfs/src/admin/handlers/replication.rs

@@ -374,8 +374,10 @@ impl RemoteTargetRequest {
 /// Admin-response encoding of a remote target: the persisted bucket-targets
 /// format keeps `healthCheckDuration`/`totalDowntime` in seconds and the
 /// `latency` stats in milliseconds, but madmin decodes all of them as Go
-/// `time.Duration` (nanoseconds) — re-encode just those fields without
-/// touching the persistence wire format.
+/// `time.Duration` (nanoseconds) — and it looks the fields up under its own
+/// JSON tags (`bandwidth`, `storageclass`, `resetID`, `deploymentID`,
+/// `credentials.sessionToken`), not the persisted snake_case keys. Re-encode
+/// just those fields here without touching the persistence wire format.
 fn remote_target_admin_json(target: &BucketTarget) -> Result<serde_json::Value, serde_json::Error> {
     fn go_duration_nanos(duration: Duration) -> serde_json::Value {
         // Saturate instead of truncating: >u64::MAX nanoseconds (~584 years)
@@ -383,6 +385,12 @@ fn remote_target_admin_json(target: &BucketTarget) -> Result<serde_json::Value,
         u64::try_from(duration.as_nanos()).unwrap_or(u64::MAX).into()
     }
 
+    fn rename_key(value: &mut serde_json::Value, from: &str, to: &str) {
+        if let Some(moved) = value.as_object_mut().and_then(|object| object.remove(from)) {
+            value[to] = moved;
+        }
+    }
+
     let mut value = serde_json::to_value(target)?;
     value["healthCheckDuration"] = go_duration_nanos(target.health_check_duration);
     value["totalDowntime"] = go_duration_nanos(target.total_downtime);
@@ -391,6 +399,11 @@ fn remote_target_admin_json(target: &BucketTarget) -> Result<serde_json::Value,
         "avg": go_duration_nanos(target.latency.avg),
         "max": go_duration_nanos(target.latency.max),
     });
+    rename_key(&mut value, "bandwidth_limit", "bandwidth");
+    rename_key(&mut value, "storage_class", "storageclass");
+    rename_key(&mut value, "reset_id", "resetID");
+    rename_key(&mut value, "deployment_id", "deploymentID");
+    rename_key(&mut value["credentials"], "session_token", "sessionToken");
     Ok(value)
 }
 
@@ -1473,7 +1486,7 @@ mod tests {
         parse_remote_target_update_ops, render_mrf_backlog, render_replication_diff, unique_replication_peers,
         validate_remote_target_tls_settings,
     };
-    use crate::admin::storage_api::bucket::target::{BucketTarget, LatencyStat};
+    use crate::admin::storage_api::bucket::target::{BucketTarget, Credentials as TargetCredentials, LatencyStat};
     use crate::admin::storage_api::replication::{BucketStats, DurableMrfBacklog, MrfOpKind, MrfReplicateEntry};
     use http::Uri;
 
@@ -2268,6 +2281,44 @@ mod tests {
         assert_eq!(persisted["latency"]["max"], 250);
     }
 
+    #[test]
+    fn list_remote_targets_response_uses_madmin_key_names() {
+        // madmin's BucketTarget JSON tags are `bandwidth`, `storageclass`,
+        // `resetID`, `deploymentID`, and `credentials.sessionToken`
+        // (backlog#1946); the persisted snake_case keys decode to zero values
+        // in mc, blanking the bandwidth and reset-id columns of
+        // `mc replicate ls`.
+        let target = BucketTarget {
+            endpoint: "192.168.1.10:9000".to_string(),
+            target_bucket: "target".to_string(),
+            credentials: Some(TargetCredentials {
+                access_key: "access".to_string(),
+                secret_key: String::new(),
+                session_token: Some("session-token".to_string()),
+                expiration: None,
+            }),
+            bandwidth_limit: 107_374_182_400,
+            storage_class: "STANDARD".to_string(),
+            reset_id: "reset-123".to_string(),
+            deployment_id: "deploy-456".to_string(),
+            ..Default::default()
+        };
+
+        let value = super::remote_target_admin_json(&target).expect("admin response should serialize");
+
+        assert_eq!(value["bandwidth"], 107_374_182_400i64);
+        assert_eq!(value["storageclass"], "STANDARD");
+        assert_eq!(value["resetID"], "reset-123");
+        assert_eq!(value["deploymentID"], "deploy-456");
+        assert_eq!(value["credentials"]["sessionToken"], "session-token");
+        // The madmin keys replace the snake_case ones rather than duplicating
+        // them next to each other.
+        for stale in ["bandwidth_limit", "storage_class", "reset_id", "deployment_id"] {
+            assert!(value.get(stale).is_none(), "admin response must not carry `{stale}`");
+        }
+        assert!(value["credentials"].get("session_token").is_none());
+    }
+
     #[test]
     fn remote_target_admin_json_latency_round_trips_through_go_duration() {
         // Round trip: a madmin reader decodes the latency values as Go