feat(server): garbage collector configuration

objectstore-server/src/config.rs

@@ -68,6 +68,7 @@ use objectstore_service::backend::local_fs::FileSystemConfig;
 #[cfg(feature = "storage-cogs")]
 use objectstore_service::change_stream::CostTrackerConfig;
 use objectstore_service::encryption::Cipher;
+use objectstore_service::garbage_collector::GarbageCollectorConfig;
 use objectstore_types::auth::Permission;
 use secrecy::{CloneableSecret, SecretBox, SerializableSecret, zeroize::Zeroize};
 use serde::{Deserialize, Serialize};
@@ -550,6 +551,32 @@ pub struct Config {
     #[serde(default)]
     pub storage_cogs: Option<CostTrackerConfig>,
 
+    /// Garbage collector configuration.
+    ///
+    /// Selects the backend of the garbage collector's expiration index, which records, per
+    /// object, the deadline at which that object becomes eligible for deletion. The index is
+    /// kept in sync on the write path and read back by the collector to find expired objects,
+    /// so it must be configured with the same lifetime as the storage backend: an index that
+    /// is lost or reset leaves objects behind with nothing scheduling their deletion.
+    ///
+    /// `None` is the default: no expiration index is configured.
+    ///
+    /// # Environment Variables
+    ///
+    /// - `OS__GARBAGE_COLLECTOR__TYPE=sqlite`
+    /// - `OS__GARBAGE_COLLECTOR__PATH=/data/objectstore.db`
+    ///
+    /// # Example
+    ///
+    /// ```yaml
+    /// garbage_collector:
+    ///   type: sqlite
+    ///   path: /data/objectstore.db
+    /// ```
+    ///
+    /// See [`GarbageCollectorConfig`] for the available backends and their fields.
+    pub garbage_collector: Option<GarbageCollectorConfig>,
+
     /// Configuration of the internal task runtime.
     ///
     /// Controls the thread pool size and behavior of the async runtime powering the server.
@@ -858,6 +885,7 @@ impl Default for Config {
 
             #[cfg(feature = "storage-cogs")]
             storage_cogs: None,
+            garbage_collector: None,
             runtime: Runtime::default(),
             logging: LoggingConfig::default(),
             sentry: Sentry::default(),

objectstore-service/src/garbage_collector/mod.rs

@@ -11,8 +11,10 @@ pub mod sqlite;
 use std::fmt::Debug;
 
 use objectstore_types::time::Timestamp;
+use serde::{Deserialize, Serialize};
 
 use crate::change_stream::ChangeStreamError;
+use crate::garbage_collector::sqlite::SqliteGarbageCollectorConfig;
 use crate::id::ObjectId;
 
 /// Stores object expiration metadata for the garbage collector.
@@ -49,3 +51,27 @@ pub trait GcStorage: Send + Sync + Debug {
         limit: u64,
     ) -> Result<Vec<ObjectId>, ChangeStreamError>;
 }
+
+/// Backend selection for the garbage collector's expiration index.
+///
+/// Each variant wraps that backend's own configuration and corresponds to a [`GcStorage`]
+/// implementation. The enum is internally tagged: in YAML the variant is named by a `type`
+/// key, and through environment variables by the `OS__GARBAGE_COLLECTOR__TYPE` prefix plus
+/// the variant's fields (e.g. `OS__GARBAGE_COLLECTOR__TYPE=sqlite`).
+///
+/// ```yaml
+/// garbage_collector:
+///   type: sqlite
+///   path: /data/objectstore.db
+/// ```
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "lowercase")]
+pub enum GarbageCollectorConfig {
+    /// SQLite-backed index, serialized as `type: sqlite`.
+    ///
+    /// Stores one row per object in a local SQLite database, see
+    /// [`SqliteGarbageCollectorConfig`] for its fields. The database file must live on
+    /// storage that survives restarts and is shared by every server that writes objects,
+    /// otherwise the index diverges from the objects actually stored.
+    Sqlite(SqliteGarbageCollectorConfig),
+}