commit 74032e5e0a5a70dc45a6a744d37b9ba24eee8d01
Author: Nicola Mometto <nicola.mometto@metabase.com>
Date:   Mon May 18 15:36:59 2026 +0100

     introduce validate-db-details multimethod (#74343)
    
    * feat: introduce validate-db-details multimethod
    
    * include mysql
    
    * add to changelog

diff --git a/enterprise/backend/src/metabase_enterprise/database_routing/api.clj b/enterprise/backend/src/metabase_enterprise/database_routing/api.clj
index f69dbe0c0a9..82c8f026a12 100644
--- a/enterprise/backend/src/metabase_enterprise/database_routing/api.clj
+++ b/enterprise/backend/src/metabase_enterprise/database_routing/api.clj
@@ -3,6 +3,7 @@
    [metabase.api.common :as api]
    [metabase.api.macros :as api.macros]
    [metabase.api.routes.common :refer [+auth]]
+   [metabase.driver :as driver]
    [metabase.driver.util :as driver.u]
    [metabase.events.core :as events]
    [metabase.settings.core :as setting]
@@ -17,9 +18,9 @@
 (api.macros/defendpoint :post "/destination-database"
   "Create new Destination Databases.
 
-  Note that unlike the normal `POST /api/database` endpoint, does NOT check the details before adding the Database.
-
-  This is OK, it's not an invariant that all database details are always valid, but it's something to note."
+  Note that unlike the normal `POST /api/database` endpoint, this endpoint does not test that the database is actually
+  reachable before adding it — destination details are not required to be valid at creation time, and an
+  unreachable destination is fine."
   [_route-params
    {:keys [check_connection_details]} :- [:map
                                           [:check_connection_details {:optional true} ms/MaybeBooleanValue]]
@@ -34,14 +35,17 @@
   (api/check-400 (not (t2/exists? :model/Database :router_database_id router_database_id :name [:in (map :name destinations)]))
                  "A destination database with that name already exists.")
   (let [{:keys [engine auto_run_queries is_on_demand] :as router-db} (t2/select-one :model/Database :id router_database_id)]
-    (if-let [invalid-destinations (and check_connection_details
-                                       (->> destinations
-                                            (keep (fn [{details :details n :name}]
-                                                    (let [details-or-error (api.database/test-connection-details (name engine) details)
-                                                          valid? (not= (:valid details-or-error) false)]
-                                                      (when-not valid?
-                                                        [n (dissoc details-or-error :valid)]))))
-                                            seq))]
+    (if-let [invalid-destinations (->> destinations
+                                       (keep (fn [{details :details n :name}]
+                                               (try
+                                                 (driver/validate-db-details! engine details)
+                                                 (when check_connection_details
+                                                   (let [details-or-error (api.database/test-connection-details (name engine) details)]
+                                                     (when (false? (:valid details-or-error))
+                                                       [n (dissoc details-or-error :valid)])))
+                                                 (catch Throwable e
+                                                   [n {:message (ex-message e)}]))))
+                                       seq)]
       {:status 400
        :body (into {} invalid-destinations)}
       (u/prog1 (t2/insert-returning-instances!
diff --git a/src/metabase/driver/h2.clj b/src/metabase/driver/h2.clj
index 3c59200f854..1f538cbab2e 100644
--- a/src/metabase/driver/h2.clj
+++ b/src/metabase/driver/h2.clj
@@ -115,8 +115,8 @@
                                         bad-markers))]
     (pred s)))
 
-(defmethod driver/can-connect? :h2
-  [driver {:keys [db] :as details}]
+(defmethod driver/validate-db-details! :h2
+  [_driver {:keys [db]}]
   (when-not driver.settings/*allow-testing-h2-connections*
     (throw (ex-info (tru "H2 is not supported as a data warehouse") {:status-code 400})))
   (when (string? db)
@@ -132,7 +132,11 @@
       ;; keys are uppercased by h2 when parsed:
       ;; https://github.com/h2database/h2database/blob/master/h2/src/main/org/h2/engine/ConnectionInfo.java#L298
       (when (contains? properties "INIT")
-        (throw (ex-info "INIT not allowed" {:keys ["INIT"]})))))
+        (throw (ex-info "INIT not allowed" {:keys ["INIT"]}))))))
+
+(defmethod driver/can-connect? :h2
+  [driver details]
+  (driver/validate-db-details! driver details)
   (sql-jdbc.conn/can-connect? driver details))
 
 (defmethod driver/db-start-of-week :h2