refactor: drop postgres backend

crates/worker/Cargo.toml

@@ -6,7 +6,6 @@ edition.workspace = true
 [features]
 default = ["sqlite", "sqlite-federation"]
 sqlite = ["dep:sqlite", "dep:sqlite-event-queue", "dep:sqlite-search", "infra-wiring/sqlite", "composition/sqlite"]
-postgres = ["dep:postgres", "dep:postgres-event-queue", "dep:postgres-search", "infra-wiring/postgres", "composition/postgres"]
 nats = ["dep:nats", "infra-wiring/nats", "composition/nats"]
 federation = ["application/federation"]
 sqlite-federation = [
@@ -16,13 +15,6 @@ sqlite-federation = [
     "federation",
     "composition/sqlite-federation",
 ]
-postgres-federation = [
-    "postgres",
-    "dep:postgres-federation",
-    "dep:activitypub",
-    "federation",
-    "composition/postgres-federation",
-]
 
 [dependencies]
 domain = { workspace = true }
@@ -49,13 +41,9 @@ async-trait = { workspace = true }
 
 # Optional — database backends
 sqlite = { workspace = true, optional = true }
-postgres = { workspace = true, optional = true }
 sqlite-event-queue   = { workspace = true, optional = true }
-postgres-event-queue = { workspace = true, optional = true }
 sqlite-search        = { workspace = true, optional = true }
-postgres-search      = { workspace = true, optional = true }
 
 # Optional — federation
 activitypub       = { workspace = true, optional = true }
 sqlite-federation = { workspace = true, optional = true }
-postgres-federation = { workspace = true, optional = true }

crates/worker/src/event_bus.rs

@@ -13,10 +13,6 @@ pub async fn create(
         EventBusBackend::Db => {
             tracing::info!("event bus: DB queue");
             match db_pool {
-                #[cfg(feature = "postgres")]
-                DbPool::Postgres(pool) => Ok(
-                    postgres_event_queue::PostgresEventQueue::create_channel(pool.clone()).await?,
-                ),
                 #[cfg(feature = "sqlite")]
                 DbPool::Sqlite(pool) => {
                     Ok(sqlite_event_queue::SqliteEventQueue::create_channel(pool.clone()).await?)

crates/worker/src/main.rs

@@ -1,4 +1,5 @@
 mod event_bus;
+#[cfg(feature = "federation")]
 mod follow_backfill_handler;
 
 use std::sync::Arc;
@@ -12,10 +13,8 @@ use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
 use domain::ports::{EventHandler, MovieEnrichmentClient, PeriodicJob, PersonEnrichmentClient};
 
-#[cfg(not(any(feature = "sqlite", feature = "postgres")))]
-compile_error!(
-    "At least one database backend must be enabled. Use --features sqlite or --features postgres"
-);
+#[cfg(not(feature = "sqlite"))]
+compile_error!("The sqlite feature must be enabled. Use --features sqlite");
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
@@ -23,7 +22,7 @@ async fn main() -> anyhow::Result<()> {
     init_tracing();
 
     let database_url = std::env::var("DATABASE_URL").context("DATABASE_URL must be set")?;
-    let backend = std::env::var("DATABASE_BACKEND").unwrap_or_else(|_| "sqlite".to_string());
+    warn_if_database_backend_set();
     let app_config = AppConfig::from_env();
     let instance = domain::value_objects::InstanceIdentity::new(app_config.base_url.clone());
 
@@ -47,8 +46,7 @@ async fn main() -> anyhow::Result<()> {
         .clone()
         .map(|c| c as Arc<dyn PersonEnrichmentClient>);
 
-    let db =
-        composition::factory::build_database_adapters(&backend, &database_url, &instance).await?;
+    let db = composition::factory::build_database_adapters(&database_url, &instance).await?;
     let (event_publisher_arc, consumer_arc) = event_bus::create(&db.db_pool).await?;
 
     let worker_services = application::WorkerServices {
@@ -88,10 +86,6 @@ async fn main() -> anyhow::Result<()> {
         composition::DbPool::Sqlite(pool) => {
             sqlite_federation::wire(pool.clone(), instance.clone())
         }
-        #[cfg(feature = "postgres-federation")]
-        composition::DbPool::Postgres(pool) => {
-            postgres_federation::wire(pool.clone(), instance.clone())
-        }
     };
 
     let movie_command = db.movie_command;
@@ -103,6 +97,7 @@ async fn main() -> anyhow::Result<()> {
     let person_query = db.person_query;
     let search_command = db.search_command;
     let wrapup_repo = db.wrapup_repo;
+    #[cfg(feature = "federation")]
     let remote_goal = db.remote_goal;
     let refresh_session = db.refresh_session;
 
@@ -306,6 +301,14 @@ async fn main() -> anyhow::Result<()> {
     Ok(())
 }
 
+fn warn_if_database_backend_set() {
+    if let Ok(v) = std::env::var("DATABASE_BACKEND")
+        && v != "sqlite"
+    {
+        tracing::warn!("DATABASE_BACKEND is ignored; SQLite is the only backend");
+    }
+}
+
 fn init_tracing() {
     tracing_subscriber::registry()
         .with(log_filter("worker=info,application=info,k_ap=info"))