merge: tier 4 hardening batch 1 (#1 #2 #21)

#1 graceful shutdown on SIGINT/SIGTERM (axum with_graceful_shutdown).
#2 configurable DB pool size (--db-max-connections / DB_MAX_CONNECTIONS, default 5).
#21 audit vocabulary/term/authority creation atomically, attributing the acting
user; ~15 call sites threaded an AuditActor.

173 workspace tests; clippy + fmt clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/api/src/admin_authorities.rs

@@ -7,7 +7,7 @@ use axum::{
     http::StatusCode,
     routing::get,
 };
-use domain::{AuthorityKind, LocalizedLabel, NewAuthority};
+use domain::{AuditActor, AuthorityKind, LocalizedLabel, NewAuthority};
 use serde::{Deserialize, Serialize};
 use utoipa::ToSchema;
 
@@ -91,7 +91,7 @@ pub(crate) async fn list_authorities(
     )
 )]
 pub(crate) async fn create_authority(
-    _auth: Authorized<EditCatalogue>,
+    auth: Authorized<EditCatalogue>,
     State(state): State<AppState>,
     Json(req): Json<NewAuthorityRequest>,
 ) -> Result<(StatusCode, Json<CreatedId>), StatusCode> {
@@ -117,9 +117,10 @@ pub(crate) async fn create_authority(
         .await
         .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
 
-    let id = db::authority::create_authority(&mut tx, &new)
+    let id =
-        .await
+        db::authority::create_authority(&mut tx, AuditActor::User(auth.user.id.to_uuid()), &new)
-        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+            .await
+            .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
 
     tx.commit()
         .await

crates/api/src/admin_vocab.rs

@@ -7,7 +7,7 @@ use axum::{
     http::StatusCode,
     routing::get,
 };
-use domain::{LocalizedLabel, NewTerm, VocabularyId};
+use domain::{AuditActor, LocalizedLabel, NewTerm, VocabularyId};
 use serde::{Deserialize, Serialize};
 use utoipa::ToSchema;
 
@@ -85,11 +85,23 @@ pub(crate) async fn list_vocabularies(
     )
 )]
 pub(crate) async fn create_vocabulary(
-    _auth: Authorized<EditCatalogue>,
+    auth: Authorized<EditCatalogue>,
     State(state): State<AppState>,
     Json(req): Json<NewVocabularyRequest>,
 ) -> Result<(StatusCode, Json<VocabularyView>), StatusCode> {
-    let vocab = db::vocab::create_vocabulary(state.db.pool(), &req.key)
+    let mut tx = state
+        .db
+        .pool()
+        .begin()
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    let vocab =
+        db::vocab::create_vocabulary(&mut tx, AuditActor::User(auth.user.id.to_uuid()), &req.key)
+            .await
+            .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    tx.commit()
         .await
         .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
 
@@ -156,7 +168,7 @@ pub(crate) async fn list_terms(
     )
 )]
 pub(crate) async fn add_term(
-    _auth: Authorized<EditCatalogue>,
+    auth: Authorized<EditCatalogue>,
     State(state): State<AppState>,
     Path(id): Path<String>,
     Json(req): Json<NewTermRequest>,
@@ -185,15 +197,17 @@ pub(crate) async fn add_term(
         .await
         .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
 
-    let term_id = db::vocab::add_term(&mut tx, &new).await.map_err(|err| {
+    let term_id = db::vocab::add_term(&mut tx, AuditActor::User(auth.user.id.to_uuid()), &new)
-        // A well-formed id for a missing vocabulary hits the FK constraint (23503).
+        .await
-        if err.as_database_error().and_then(|e| e.code()).as_deref() == Some("23503") {
+        .map_err(|err| {
-            StatusCode::NOT_FOUND
+            // A well-formed id for a missing vocabulary hits the FK constraint (23503).
-        } else {
+            if err.as_database_error().and_then(|e| e.code()).as_deref() == Some("23503") {
-            tracing::error!(?err, "adding term");
+                StatusCode::NOT_FOUND
-            StatusCode::INTERNAL_SERVER_ERROR
+            } else {
-        }
+                tracing::error!(?err, "adding term");
-    })?;
+                StatusCode::INTERNAL_SERVER_ERROR
+            }
+        })?;
 
     tx.commit()
         .await

crates/api/tests/admin_catalog.rs

@@ -1,8 +1,8 @@
 use api::{AppState, build_app, migrate_sessions};
 use axum::body::Body;
 use axum::http::{Request, StatusCode, header};
-use db::users;
+use db::{audit, users};
-use domain::{AuditActor, Email, NewUser, Role};
+use domain::{AuditAction, AuditActor, Email, NewUser, Role};
 use http_body_util::BodyExt;
 use sqlx::PgPool;
 use tower::ServiceExt;
@@ -290,3 +290,44 @@ async fn add_term_to_missing_vocabulary_is_404(pool: PgPool) {
 
     assert_eq!(resp.status(), StatusCode::NOT_FOUND);
 }
+
+#[sqlx::test(migrations = "../db/migrations")]
+async fn creating_a_vocabulary_writes_an_audit_entry(pool: PgPool) {
+    migrate_sessions(&db::Db::from_pool(pool.clone()))
+        .await
+        .unwrap();
+
+    seed_user(&pool, "ed@example.com", "pw-editor-123", Role::Editor).await;
+
+    let app = build_app(state(pool.clone()));
+    let cookie = login(&app, "ed@example.com", "pw-editor-123").await;
+
+    let resp = app
+        .oneshot(
+            Request::builder()
+                .method("POST")
+                .uri("/api/admin/vocabularies")
+                .header(header::COOKIE, &cookie)
+                .header(header::CONTENT_TYPE, "application/json")
+                .body(Body::from(r#"{"key":"audit-test"}"#))
+                .unwrap(),
+        )
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), StatusCode::CREATED);
+
+    let body: serde_json::Value =
+        serde_json::from_slice(&resp.into_body().collect().await.unwrap().to_bytes()).unwrap();
+    let vocab_id: uuid::Uuid = body["id"].as_str().unwrap().parse().unwrap();
+
+    let history = audit::history_for(&pool, "vocabulary", vocab_id)
+        .await
+        .unwrap();
+
+    assert_eq!(history.len(), 1);
+    assert_eq!(history[0].action, AuditAction::Created);
+    assert!(
+        matches!(history[0].actor, AuditActor::User(_)),
+        "expected actor to be a user"
+    );
+}

crates/db/src/authority.rs

@@ -1,16 +1,25 @@
 //! Authority records (person / organisation / place).
 
-use domain::{Authority, AuthorityId, AuthorityKind, AuthorityRef, LocalizedLabel, NewAuthority};
+use domain::{
+    AuditAction, AuditActor, Authority, AuthorityId, AuthorityKind, AuthorityRef, LocalizedLabel,
+    NewAuditEvent, NewAuthority,
+};
 use sqlx::Row;
 
+use crate::audit;
+
+const AUTHORITY_ENTITY_TYPE: &str = "authority";
+
 /// Labels aggregated per row as JSON, to read an authority and its labels in one query.
 const LABELS_JSON: &str = "COALESCE(json_agg(json_build_object('lang', al.lang, 'label', al.label) \
      ORDER BY al.lang) FILTER (WHERE al.authority_id IS NOT NULL), '[]'::json)";
 
-/// Insert an authority and its labels. Multiple statements — pass a transaction
+/// Insert an authority and its labels, then record a `created` audit entry. Multiple
-/// connection (`&mut *tx`) for atomicity.
+/// statements — pass a transaction connection (`&mut *tx`) so everything commits
+/// atomically.
 pub async fn create_authority(
     conn: &mut sqlx::PgConnection,
+    actor: AuditActor,
     new: &NewAuthority,
 ) -> Result<AuthorityId, sqlx::Error> {
     let id = AuthorityId::new();
@@ -31,6 +40,18 @@ pub async fn create_authority(
             .await?;
     }
 
+    audit::record(
+        &mut *conn,
+        &NewAuditEvent {
+            actor,
+            action: AuditAction::Created,
+            entity_type: AUTHORITY_ENTITY_TYPE.to_owned(),
+            entity_id: id.to_uuid(),
+            changes: Vec::new(),
+        },
+    )
+    .await?;
+
     Ok(id)
 }
 

crates/db/src/lib.rs

@@ -17,10 +17,11 @@ pub struct Db {
 }
 
 impl Db {
-    /// Connect to the database at `database_url`, opening a connection pool.
+    /// Connect to the database at `database_url`, opening a connection pool with at most
-    pub async fn connect(database_url: &str) -> Result<Self, sqlx::Error> {
+    /// `max_connections` connections.
+    pub async fn connect(database_url: &str, max_connections: u32) -> Result<Self, sqlx::Error> {
         let pool = PgPoolOptions::new()
-            .max_connections(5)
+            .max_connections(max_connections)
             .connect(database_url)
             .await?;
 

crates/db/src/seed.rs

@@ -5,7 +5,9 @@
 //! populated by the organization or a later import. The inventory-minimum fields
 //! (object number, name, location, …) live in the typed object core, not here.
 
-use domain::{AuthorityKind, FieldType, LocalizedLabel, NewFieldDefinition, VocabularyId};
+use domain::{
+    AuditActor, AuthorityKind, FieldType, LocalizedLabel, NewFieldDefinition, VocabularyId,
+};
 
 use crate::{fields, vocab};
 
@@ -119,7 +121,11 @@ async fn ensure_vocabulary(
     if let Some(existing) = vocab::vocabulary_by_key(&mut *conn, key).await? {
         Ok(existing.id)
     } else {
-        Ok(vocab::create_vocabulary(&mut *conn, key).await?.id)
+        Ok(
+            vocab::create_vocabulary(&mut *conn, AuditActor::System, key)
+                .await?
+                .id,
+        )
     }
 }
 

crates/db/src/vocab.rs

@@ -1,25 +1,47 @@
 //! Controlled vocabularies and terms.
 
-use domain::{LocalizedLabel, NewTerm, Term, TermId, TermRef, Vocabulary, VocabularyId};
+use domain::{
+    AuditAction, AuditActor, LocalizedLabel, NewAuditEvent, NewTerm, Term, TermId, TermRef,
+    Vocabulary, VocabularyId,
+};
 use sqlx::Row;
 
+use crate::audit;
+
+const VOCABULARY_ENTITY_TYPE: &str = "vocabulary";
+const TERM_ENTITY_TYPE: &str = "term";
+
 /// Labels aggregated per row as JSON, to read a term and its labels in one query.
 const LABELS_JSON: &str = "COALESCE(json_agg(json_build_object('lang', tl.lang, 'label', tl.label) \
      ORDER BY tl.lang) FILTER (WHERE tl.term_id IS NOT NULL), '[]'::json)";
 
-/// Create a vocabulary with the given key.
+/// Create a vocabulary with the given key and record a `created` audit entry, both on
-pub async fn create_vocabulary<'e, E>(executor: E, key: &str) -> Result<Vocabulary, sqlx::Error>
+/// `conn` (pass a transaction connection `&mut *tx` so they commit atomically).
-where
+pub async fn create_vocabulary(
-    E: sqlx::PgExecutor<'e>,
+    conn: &mut sqlx::PgConnection,
-{
+    actor: AuditActor,
+    key: &str,
+) -> Result<Vocabulary, sqlx::Error> {
     let id = VocabularyId::new();
 
     sqlx::query("INSERT INTO vocabulary (id, key) VALUES ($1, $2)")
         .bind(id.to_uuid())
         .bind(key)
-        .execute(executor)
+        .execute(&mut *conn)
         .await?;
 
+    audit::record(
+        &mut *conn,
+        &NewAuditEvent {
+            actor,
+            action: AuditAction::Created,
+            entity_type: VOCABULARY_ENTITY_TYPE.to_owned(),
+            entity_id: id.to_uuid(),
+            changes: Vec::new(),
+        },
+    )
+    .await?;
+
     Ok(Vocabulary {
         id,
         key: key.to_owned(),
@@ -54,9 +76,14 @@ where
     row.map(map_vocabulary).transpose()
 }
 
-/// Insert a term and its labels. Multiple statements — pass a transaction
+/// Insert a term and its labels, then record a `created` audit entry. Multiple
-/// connection (`&mut *tx`) so the term and its labels commit atomically.
+/// statements — pass a transaction connection (`&mut *tx`) so everything commits
-pub async fn add_term(conn: &mut sqlx::PgConnection, new: &NewTerm) -> Result<TermId, sqlx::Error> {
+/// atomically.
+pub async fn add_term(
+    conn: &mut sqlx::PgConnection,
+    actor: AuditActor,
+    new: &NewTerm,
+) -> Result<TermId, sqlx::Error> {
     let id = TermId::new();
 
     sqlx::query("INSERT INTO term (id, vocabulary_id, external_uri) VALUES ($1, $2, $3)")
@@ -75,6 +102,18 @@ pub async fn add_term(conn: &mut sqlx::PgConnection, new: &NewTerm) -> Result<Te
             .await?;
     }
 
+    audit::record(
+        &mut *conn,
+        &NewAuditEvent {
+            actor,
+            action: AuditAction::Created,
+            entity_type: TERM_ENTITY_TYPE.to_owned(),
+            entity_id: id.to_uuid(),
+            changes: Vec::new(),
+        },
+    )
+    .await?;
+
     Ok(id)
 }
 

crates/db/tests/authority.rs

@@ -1,5 +1,5 @@
 use db::{Db, authority};
-use domain::{AuthorityKind, LocalizedLabel, NewAuthority};
+use domain::{AuditActor, AuthorityKind, LocalizedLabel, NewAuthority};
 use sqlx::PgPool;
 
 fn new_person(name_sv: &str, name_en: &str) -> NewAuthority {
@@ -24,9 +24,13 @@ async fn authority_round_trips_with_labels(pool: PgPool) {
     let db = Db::from_pool(pool);
 
     let mut tx = db.pool().begin().await.unwrap();
-    let id = authority::create_authority(&mut tx, &new_person("Carl Larsson", "Carl Larsson"))
+    let id = authority::create_authority(
-        .await
+        &mut tx,
-        .unwrap();
+        AuditActor::System,
+        &new_person("Carl Larsson", "Carl Larsson"),
+    )
+    .await
+    .unwrap();
     tx.commit().await.unwrap();
 
     let got = authority::authority_by_id(db.pool(), id)
@@ -47,11 +51,12 @@ async fn list_by_kind_filters(pool: PgPool) {
     let db = Db::from_pool(pool);
 
     let mut tx = db.pool().begin().await.unwrap();
-    authority::create_authority(&mut tx, &new_person("A", "A"))
+    authority::create_authority(&mut tx, AuditActor::System, &new_person("A", "A"))
         .await
         .unwrap();
     authority::create_authority(
         &mut tx,
+        AuditActor::System,
         &NewAuthority {
             kind: AuthorityKind::Place,
             external_uri: None,
@@ -83,7 +88,7 @@ async fn resolve_authority_returns_kind(pool: PgPool) {
     let db = Db::from_pool(pool);
 
     let mut tx = db.pool().begin().await.unwrap();
-    let id = authority::create_authority(&mut tx, &new_person("X", "X"))
+    let id = authority::create_authority(&mut tx, AuditActor::System, &new_person("X", "X"))
         .await
         .unwrap();
     tx.commit().await.unwrap();
@@ -108,6 +113,7 @@ async fn authority_with_no_labels_round_trips_empty(pool: PgPool) {
     let mut tx = db.pool().begin().await.unwrap();
     let id = authority::create_authority(
         &mut tx,
+        AuditActor::System,
         &NewAuthority {
             kind: AuthorityKind::Organisation,
             external_uri: None,

crates/db/tests/fields.rs

@@ -1,5 +1,5 @@
 use db::{Db, fields, vocab};
-use domain::{AuthorityKind, FieldType, LocalizedLabel, NewFieldDefinition};
+use domain::{AuditActor, AuthorityKind, FieldType, LocalizedLabel, NewFieldDefinition};
 use sqlx::PgPool;
 
 fn labels() -> Vec<LocalizedLabel> {
@@ -52,9 +52,11 @@ async fn text_field_round_trips(pool: PgPool) {
 #[sqlx::test]
 async fn term_and_authority_fields_round_trip_their_binding(pool: PgPool) {
     let db = Db::from_pool(pool);
-    let material = vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+    let material = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
+    tx.commit().await.unwrap();
 
     let mut tx = db.pool().begin().await.unwrap();
     fields::create_field_definition(

crates/db/tests/object_fields.rs

@@ -95,9 +95,12 @@ async fn sets_scalar_fields_and_audits(pool: PgPool) {
 async fn term_field_must_resolve_in_its_vocabulary(pool: PgPool) {
     let db = Db::from_pool(pool);
     let id = setup_object(&db).await;
-    let material = vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+    let material = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
+    tx.commit().await.unwrap();
+
     define(
         &db,
         "material",
@@ -110,6 +113,7 @@ async fn term_field_must_resolve_in_its_vocabulary(pool: PgPool) {
     let mut tx = db.pool().begin().await.unwrap();
     let wood = vocab::add_term(
         &mut tx,
+        AuditActor::System,
         &domain::NewTerm {
             vocabulary_id: material.id,
             external_uri: None,
@@ -180,6 +184,7 @@ async fn authority_field_enforces_kind(pool: PgPool) {
     let mut tx = db.pool().begin().await.unwrap();
     let person = db::authority::create_authority(
         &mut tx,
+        AuditActor::System,
         &domain::NewAuthority {
             kind: domain::AuthorityKind::Person,
             external_uri: None,
@@ -190,6 +195,7 @@ async fn authority_field_enforces_kind(pool: PgPool) {
     .unwrap();
     let place = db::authority::create_authority(
         &mut tx,
+        AuditActor::System,
         &domain::NewAuthority {
             kind: domain::AuthorityKind::Place,
             external_uri: None,
@@ -219,12 +225,14 @@ async fn authority_field_enforces_kind(pool: PgPool) {
 async fn term_from_wrong_vocabulary_is_rejected(pool: PgPool) {
     let db = Db::from_pool(pool);
     let id = setup_object(&db).await;
-    let material = vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+    let material = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
-    let technique = vocab::create_vocabulary(db.pool(), "technique")
+    let technique = vocab::create_vocabulary(&mut tx, AuditActor::System, "technique")
         .await
         .unwrap();
+    tx.commit().await.unwrap();
     define(
         &db,
         "material",
@@ -238,6 +246,7 @@ async fn term_from_wrong_vocabulary_is_rejected(pool: PgPool) {
     let mut tx = db.pool().begin().await.unwrap();
     let other = vocab::add_term(
         &mut tx,
+        AuditActor::System,
         &domain::NewTerm {
             vocabulary_id: technique.id,
             external_uri: None,

crates/db/tests/vocab.rs

@@ -1,13 +1,15 @@
 use db::{Db, vocab};
-use domain::{LocalizedLabel, NewTerm};
+use domain::{AuditActor, LocalizedLabel, NewTerm};
 use sqlx::PgPool;
 
 #[sqlx::test]
 async fn vocabulary_create_and_lookup(pool: PgPool) {
     let db = Db::from_pool(pool);
-    let v = vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+    let v = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
+    tx.commit().await.unwrap();
 
     let found = vocab::vocabulary_by_key(db.pool(), "material")
         .await
@@ -27,13 +29,16 @@ async fn vocabulary_create_and_lookup(pool: PgPool) {
 #[sqlx::test]
 async fn term_with_multilingual_labels_round_trips(pool: PgPool) {
     let db = Db::from_pool(pool);
-    let v = vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+    let v = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
+    tx.commit().await.unwrap();
 
     let mut tx = db.pool().begin().await.unwrap();
     let term_id = vocab::add_term(
         &mut tx,
+        AuditActor::System,
         &NewTerm {
             vocabulary_id: v.id,
             external_uri: Some("http://vocab.getty.edu/aat/300011914".into()),
@@ -76,13 +81,16 @@ async fn term_with_multilingual_labels_round_trips(pool: PgPool) {
 #[sqlx::test]
 async fn term_with_no_labels_round_trips_empty(pool: PgPool) {
     let db = Db::from_pool(pool);
-    let v = vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+    let v = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
+    tx.commit().await.unwrap();
 
     let mut tx = db.pool().begin().await.unwrap();
     let term_id = vocab::add_term(
         &mut tx,
+        AuditActor::System,
         &NewTerm {
             vocabulary_id: v.id,
             external_uri: None,
@@ -103,10 +111,14 @@ async fn term_with_no_labels_round_trips_empty(pool: PgPool) {
 #[sqlx::test]
 async fn duplicate_vocabulary_key_is_rejected(pool: PgPool) {
     let db = Db::from_pool(pool);
-    vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+    vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
-    let err = vocab::create_vocabulary(db.pool(), "material")
+    tx.commit().await.unwrap();
+
+    let mut tx = db.pool().begin().await.unwrap();
+    let err = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap_err();
     assert!(
@@ -118,16 +130,19 @@ async fn duplicate_vocabulary_key_is_rejected(pool: PgPool) {
 #[sqlx::test]
 async fn resolve_term_checks_vocabulary_membership(pool: PgPool) {
     let db = Db::from_pool(pool);
-    let material = vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+    let material = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
-    let technique = vocab::create_vocabulary(db.pool(), "technique")
+    let technique = vocab::create_vocabulary(&mut tx, AuditActor::System, "technique")
         .await
         .unwrap();
+    tx.commit().await.unwrap();
 
     let mut tx = db.pool().begin().await.unwrap();
     let term_id = vocab::add_term(
         &mut tx,
+        AuditActor::System,
         &NewTerm {
             vocabulary_id: material.id,
             external_uri: None,

crates/search/tests/reindex.rs

@@ -23,14 +23,15 @@ async fn reindex_resolves_term_labels_and_finds_by_label(pool: PgPool) {
     let db = Db::from_pool(pool);
 
     // a material vocabulary with a "wood" term
-    let material = vocab::create_vocabulary(db.pool(), "material")
+    let mut tx = db.pool().begin().await.unwrap();
+
+    let material = vocab::create_vocabulary(&mut tx, AuditActor::System, "material")
         .await
         .unwrap();
 
-    let mut tx = db.pool().begin().await.unwrap();
-
     let wood = vocab::add_term(
         &mut tx,
+        AuditActor::System,
         &NewTerm {
             vocabulary_id: material.id,
             external_uri: None,

crates/server/src/config.rs

@@ -42,4 +42,12 @@ pub struct Config {
     /// Meilisearch index name for catalogue objects.
     #[arg(long = "meili-index", env = "MEILI_INDEX", default_value = "objects")]
     pub meili_index: String,
+
+    /// Maximum size of the PostgreSQL connection pool.
+    #[arg(
+        long = "db-max-connections",
+        env = "DB_MAX_CONNECTIONS",
+        default_value_t = 5
+    )]
+    pub db_max_connections: u32,
 }

crates/server/src/lib.rs

@@ -15,7 +15,7 @@ use tokio::net::TcpListener;
 
 /// Connect dependencies from `config` and serve until shutdown.
 pub async fn run(config: Config) -> anyhow::Result<()> {
-    let db = Db::connect(&config.database_url)
+    let db = Db::connect(&config.database_url, config.db_max_connections)
         .await
         .context("connecting to the database")?;
 
@@ -64,6 +64,34 @@ pub async fn run(config: Config) -> anyhow::Result<()> {
     serve(listener, state).await
 }
 
+/// Resolves when the process receives SIGINT (Ctrl-C) or SIGTERM, so the server can
+/// drain in-flight requests before exiting.
+async fn shutdown_signal() {
+    let ctrl_c = async {
+        tokio::signal::ctrl_c()
+            .await
+            .expect("install Ctrl-C handler");
+    };
+
+    #[cfg(unix)]
+    let terminate = async {
+        tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate())
+            .expect("install SIGTERM handler")
+            .recv()
+            .await;
+    };
+
+    #[cfg(not(unix))]
+    let terminate = std::future::pending::<()>();
+
+    tokio::select! {
+        _ = ctrl_c => {},
+        _ = terminate => {},
+    }
+
+    tracing::info!("shutdown signal received; draining");
+}
+
 /// Serve the API on an already-bound listener (used by `run` and tests).
 pub async fn serve(listener: TcpListener, state: AppState) -> anyhow::Result<()> {
     let app = build_app(state);
@@ -72,6 +100,7 @@ pub async fn serve(listener: TcpListener, state: AppState) -> anyhow::Result<()>
     let app = app.merge(web_assets::routes());
 
     axum::serve(listener, app)
+        .with_graceful_shutdown(shutdown_signal())
         .await
         .context("running the HTTP server")?;
 
@@ -107,7 +136,8 @@ pub async fn create_user(database_url: &str, email: &str, role: Role) -> anyhow:
         auth::hash_password(&password).map_err(|err| anyhow::anyhow!("hashing password: {err}"))?
     };
 
-    let db = Db::connect(database_url)
+    // CLI one-shot: a tiny pool is plenty.
+    let db = Db::connect(database_url, 2)
         .await
         .context("connecting to the database")?;
 

crates/server/tests/serve.rs

@@ -9,7 +9,7 @@ use tokio::net::TcpListener;
 async fn serves_health_live_over_tcp() {
     let database_url =
         std::env::var("DATABASE_URL").expect("DATABASE_URL must be set for this test");
-    let db = Db::connect(&database_url)
+    let db = Db::connect(&database_url, 2)
         .await
         .expect("connect to database");
     let state = AppState {