From d7a79d960b56170e59e10a2b6b047ddc2564f931 Mon Sep 17 00:00:00 2001
From: Diego Imbert <diego@windmill.dev>
Date: Wed, 25 Mar 2026 17:38:28 +0100
Subject: [PATCH] refactor: extract drop_custom_instance_database into
 windmill-common

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 backend/windmill-api-settings/src/lib.rs      | 22 +----------
 .../src/workspaces_extra.rs                   | 10 +----
 backend/windmill-common/src/lib.rs            | 38 +++++++++++++++++++
 3 files changed, 40 insertions(+), 30 deletions(-)

diff --git a/backend/windmill-api-settings/src/lib.rs b/backend/windmill-api-settings/src/lib.rs
index df34c01081..f3283e5235 100644
--- a/backend/windmill-api-settings/src/lib.rs
+++ b/backend/windmill-api-settings/src/lib.rs
@@ -1042,27 +1042,7 @@ async fn drop_custom_instance_pg_database(
         )));
     }
 
-    // Terminate all connections to the database before dropping
-    sqlx::query(&format!(
-        "SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = '{dbname}' AND pid <> pg_backend_pid()"
-    ))
-    .execute(&db)
-    .await?;
-
-    sqlx::query(&format!("DROP DATABASE \"{dbname}\""))
-        .execute(&db)
-        .await
-        .map_err(|e| {
-            error::Error::ExecutionErr(format!("Failed to drop database '{}': {}", dbname, e))
-        })?;
-
-    // Remove from global_settings
-    sqlx::query!(
-        r#"UPDATE global_settings SET value = value #- ARRAY['databases', $1] WHERE name = 'custom_instance_pg_databases'"#,
-        dbname
-    )
-    .execute(&db)
-    .await?;
+    windmill_common::drop_custom_instance_database(&db, dbname).await;
 
     Ok(format!("Database '{}' dropped successfully", dbname))
 }
diff --git a/backend/windmill-api-workspaces/src/workspaces_extra.rs b/backend/windmill-api-workspaces/src/workspaces_extra.rs
index df9f42e4e1..629a8fc42e 100644
--- a/backend/windmill-api-workspaces/src/workspaces_extra.rs
+++ b/backend/windmill-api-workspaces/src/workspaces_extra.rs
@@ -899,15 +899,7 @@ async fn drop_forked_datatable_databases(
         if dt.database.resource_type
             == windmill_common::workspaces::DataTableCatalogResourceType::Instance
         {
-            match sqlx::query(&format!("DROP DATABASE IF EXISTS \"{}\"", db_to_drop))
-                .execute(db)
-                .await
-            {
-                Ok(_) => tracing::info!("Dropped instance database '{}'", db_to_drop),
-                Err(e) => {
-                    tracing::error!("Failed to drop instance database '{}': {}", db_to_drop, e)
-                }
-            }
+            windmill_common::drop_custom_instance_database(db, db_to_drop).await;
         } else if let Some(original_resource) = forked_from.get("original_resource") {
             let pg = match serde_json::from_value::<PgDatabase>(original_resource.clone()) {
                 Ok(pg) => pg,
diff --git a/backend/windmill-common/src/lib.rs b/backend/windmill-common/src/lib.rs
index 18fadbfbc7..733f7622b3 100644
--- a/backend/windmill-common/src/lib.rs
+++ b/backend/windmill-common/src/lib.rs
@@ -552,6 +552,44 @@ impl PgDatabase {
     }
 }
 
+/// Drop a custom instance database: terminate connections, DROP DATABASE, remove from global_settings.
+/// Non-fatal variant that logs errors instead of returning them.
+pub async fn drop_custom_instance_database(db: &DB, dbname: &str) {
+    // Terminate active connections
+    if let Err(e) = sqlx::query(&format!(
+        "SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = '{}' AND pid <> pg_backend_pid()",
+        dbname.replace('\'', "''")
+    ))
+    .execute(db)
+    .await
+    {
+        tracing::warn!("Failed to terminate connections to '{}': {}", dbname, e);
+    }
+
+    // Drop the database
+    match sqlx::query(&format!("DROP DATABASE IF EXISTS \"{}\"", dbname))
+        .execute(db)
+        .await
+    {
+        Ok(_) => tracing::info!("Dropped instance database '{}'", dbname),
+        Err(e) => {
+            tracing::error!("Failed to drop instance database '{}': {}", dbname, e);
+            return;
+        }
+    }
+
+    // Remove from global_settings
+    if let Err(e) = sqlx::query!(
+        r#"UPDATE global_settings SET value = value #- ARRAY['databases', $1] WHERE name = 'custom_instance_pg_databases'"#,
+        dbname
+    )
+    .execute(db)
+    .await
+    {
+        tracing::error!("Failed to remove '{}' from global_settings: {}", dbname, e);
+    }
+}
+
 #[derive(Clone)]
 pub enum DatabaseUrl {
     #[cfg(all(feature = "enterprise", feature = "private"))]