feat: add env-variable for db max connections

.env.example

@@ -5,6 +5,8 @@ RUST_LOG=debug
 MINT_APP_ENV=dev
 # connection string for the postgres database
 MINT_DB_URL=postgres://postgres:[email protected]/moksha-mint
+# Set the maximum number of connections that the pool should maintain (default 5) (optional)
+MINT_DB_MAX_CONNECTIONS=5
 # the private key of the mint
 MINT_PRIVATE_KEY=superprivatesecretkey
 

integrationtests/tests/tests.rs

@@ -45,6 +45,7 @@ pub fn test_integration() -> anyhow::Result<()> {
                     "postgres://postgres:postgres@localhost:{}/postgres",
                     host_port
                 ),
+                ..Default::default()
             };
 
             let mint = MintBuilder::new()

moksha-mint/src/config.rs

@@ -235,10 +235,22 @@ impl From<BtcOnchainConfig> for Nut15 {
     }
 }
 
-#[derive(Debug, Clone, Default, Parser)]
+#[derive(Debug, Clone, Parser)]
 pub struct DatabaseConfig {
     #[clap(long, env = "MINT_DB_URL")]
     pub db_url: String,
+
+    #[clap(long, default_value_t = 5, env = "MINT_DB_MAX_CONNECTIONS")]
+    pub max_connections: u32,
+}
+
+impl Default for DatabaseConfig {
+    fn default() -> Self {
+        Self {
+            db_url: "".to_owned(),
+            max_connections: 5,
+        }
+    }
 }
 
 #[derive(Debug, Clone, Parser)]

moksha-mint/src/database/postgres.rs

@@ -25,7 +25,7 @@ impl PostgresDB {
     pub async fn new(config: &DatabaseConfig) -> Result<Self, sqlx::Error> {
         Ok(Self {
             pool: PgPoolOptions::new()
-                .max_connections(5) // FIXME make max connections configurable
+                .max_connections(config.max_connections)
                 .connect(config.db_url.as_str())
                 .await?,
         })

moksha-mint/src/mint.rs

@@ -744,6 +744,7 @@ mod tests {
             &format!("postgres://postgres:[email protected]:{}/postgres", port);
         let db = PostgresDB::new(&DatabaseConfig {
             db_url: connection_string.to_owned(),
+            ..Default::default()
         })
         .await?;
         db.migrate().await;

moksha-mint/src/server.rs

@@ -443,6 +443,7 @@ mod tests {
             &format!("postgres://postgres:[email protected]:{}/postgres", port);
         let db = PostgresDB::new(&DatabaseConfig {
             db_url: connection_string.to_owned(),
+            ..Default::default()
         })
         .await?;
         db.migrate().await;