server: Allow configuring max database connections

We set it to 20 by default. The SQLx default is 10.

server/src/config.rs

@@ -129,6 +129,10 @@ pub struct DatabaseConfig {
     /// If enabled, a heartbeat query will be sent every minute.
     #[serde(default = "default_db_heartbeat")]
     pub heartbeat: bool,
+
+    /// The maximum number of concurrent connections to maintain.
+    #[serde(default = "default_db_max_connections")]
+    pub max_connections: u32,
 }
 
 /// File storage configuration.
@@ -315,6 +319,10 @@ fn default_db_heartbeat() -> bool {
     false
 }
 
+fn default_db_max_connections() -> u32 {
+    20
+}
+
 fn default_soft_delete_caches() -> bool {
     false
 }

server/src/lib.rs

@@ -37,7 +37,7 @@ use axum::{
     http::{uri::Scheme, Uri},
     Router,
 };
-use sea_orm::{query::Statement, ConnectionTrait, Database, DatabaseConnection};
+use sea_orm::{query::Statement, ConnectionTrait, ConnectOptions, Database, DatabaseConnection};
 use tokio::sync::OnceCell;
 use tokio::time;
 use tower_http::catch_panic::CatchPanicLayer;
@@ -105,7 +105,11 @@ impl StateInner {
     async fn database(&self) -> ServerResult<&DatabaseConnection> {
         self.database
             .get_or_try_init(|| async {
-                Database::connect(&self.config.database.url)
+                let options = ConnectOptions::new(self.config.database.url.to_owned())
+                    .max_connections(self.config.database.max_connections)
+                    .to_owned();
+
+                Database::connect(options)
                     .await
                     .map_err(ServerError::database_error)
             })