feat(ecstore): add on-demand migration bucket config model

Introduce OnDemandMigrationConfig (deny_unknown_fields, version 1) with typed validation, credential redaction, a secret-free Debug impl, and the OnceLock publish hook the runtime registers into. Exported through the api facade.

crates/ecstore/src/api/mod.rs

@@ -128,7 +128,6 @@ pub mod bucket {
     }
 
     pub mod metadata {
-        pub use crate::bucket::metadata::BUCKET_DURABILITY_CONFIG;
         pub use crate::bucket::metadata::{
             BUCKET_ACCELERATE_CONFIG, BUCKET_CORS_CONFIG, BUCKET_LIFECYCLE_CONFIG, BUCKET_LOGGING_CONFIG,
             BUCKET_NOTIFICATION_CONFIG, BUCKET_POLICY_CONFIG, BUCKET_PUBLIC_ACCESS_BLOCK_CONFIG, BUCKET_QUOTA_CONFIG_FILE,
@@ -137,6 +136,7 @@ pub mod bucket {
             BUCKET_TARGETS_FILE, BUCKET_VERSIONING_CONFIG, BUCKET_WEBSITE_CONFIG, BucketMetadata, OBJECT_LOCK_CONFIG,
             load_bucket_metadata, table_catalog_path_hash,
         };
+        pub use crate::bucket::metadata::{BUCKET_DURABILITY_CONFIG, BUCKET_ON_DEMAND_MIGRATION_CONFIG};
     }
 
     pub mod durability {
@@ -145,6 +145,14 @@ pub mod bucket {
         };
     }
 
+    pub mod on_demand_migration {
+        pub use crate::bucket::on_demand_migration::{
+            ConfigPublishHook, FilterConfig, HeadPolicy, ON_DEMAND_MIGRATION_CONFIG_HOOK, ON_DEMAND_MIGRATION_CONFIG_VERSION,
+            OnDemandMigrationConfig, OnDemandMigrationConfigError, PathStyle, PolicyConfig, Provider, RangeGetPolicy,
+            SourceConfig, SourceCredentials, SourceErrorPolicy, SourceTimeout, TlsConfig, ValidationContext,
+        };
+    }
+
     pub mod metadata_sys {
         #[cfg(feature = "test-util")]
         pub use crate::bucket::metadata_sys::ConfigWriteLockProbe;
@@ -154,11 +162,11 @@ pub mod bucket {
             delete_if_incarnation, delete_under_transaction_lock, get, get_accelerate_config, get_bucket_policy,
             get_bucket_policy_raw, get_bucket_targets_config, get_config_from_disk, get_cors_config, get_durability_config,
             get_global_bucket_metadata_sys, get_lifecycle_config, get_logging_config, get_notification_config,
-            get_object_lock_config, get_object_lock_config_state, get_public_access_block_config, get_quota_config,
-            get_replication_config, get_request_payment_config, get_sse_config, get_tagging_config, get_versioning_config,
-            get_website_config, init_bucket_metadata_sys, list_bucket_targets, reload_bucket_metadata, remove_bucket_metadata,
-            set_bucket_metadata, update, update_bucket_targets_under_transaction_lock, update_config_with, update_if_incarnation,
-            update_quota_if_incarnation, update_under_transaction_lock,
+            get_object_lock_config, get_object_lock_config_state, get_on_demand_migration_config, get_public_access_block_config,
+            get_quota_config, get_replication_config, get_request_payment_config, get_sse_config, get_tagging_config,
+            get_versioning_config, get_website_config, init_bucket_metadata_sys, list_bucket_targets, reload_bucket_metadata,
+            remove_bucket_metadata, set_bucket_metadata, update, update_bucket_targets_under_transaction_lock,
+            update_config_with, update_if_incarnation, update_quota_if_incarnation, update_under_transaction_lock,
         };
     }
 

crates/ecstore/src/bucket/mod.rs

@@ -26,6 +26,7 @@ mod metadata_test;
 pub mod migration;
 mod msgp_decode;
 pub mod object_lock;
+pub mod on_demand_migration;
 pub mod policy_sys;
 pub mod quota;
 pub mod replication;

crates/ecstore/src/bucket/on_demand_migration/mod.rs

@@ -0,0 +1,27 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! On-Demand Migration (ODM): a bucket can name an external S3-compatible
+//! source bucket; GET misses are served from that source and backfilled
+//! locally. This module owns the bucket-level configuration model
+//! (`on-demand-migration.json` in the bucket metadata file); the runtime is
+//! layered on top of it by later tasks (rustfs/backlog#2147).
+
+pub mod config;
+
+pub use config::{
+    ConfigPublishHook, FilterConfig, HeadPolicy, ON_DEMAND_MIGRATION_CONFIG_HOOK, ON_DEMAND_MIGRATION_CONFIG_VERSION,
+    OnDemandMigrationConfig, OnDemandMigrationConfigError, PathStyle, PolicyConfig, Provider, RangeGetPolicy, SourceConfig,
+    SourceCredentials, SourceErrorPolicy, SourceTimeout, TlsConfig, ValidationContext,
+};