use REDIS_URL if present

config/runtime.exs

@@ -56,20 +56,50 @@ if config_env() == :prod do
   host = System.get_env("PHX_HOST") || "example.com"
 
   # Configure Redis/Valkey connection
-  redis_host = System.get_env("REDIS_HOST") || "localhost"
-  redis_port = String.to_integer(System.get_env("REDIS_PORT") || "6379")
-  redis_password = System.get_env("REDIS_PASSWORD")
-
-  redis_config = [
-    host: redis_host,
-    port: redis_port
-  ]
-
+  # Dokku sets REDIS_URL, K8s uses individual env vars
   redis_config =
-    if redis_password do
-      Keyword.put(redis_config, :password, redis_password)
-    else
-      redis_config
+    case System.get_env("REDIS_URL") do
+      nil ->
+        # Use individual env vars (K8s pattern)
+        redis_host = System.get_env("REDIS_HOST") || "localhost"
+        redis_port = String.to_integer(System.get_env("REDIS_PORT") || "6379")
+        redis_password = System.get_env("REDIS_PASSWORD")
+
+        base_config = [
+          host: redis_host,
+          port: redis_port
+        ]
+
+        if redis_password do
+          Keyword.put(base_config, :password, redis_password)
+        else
+          base_config
+        end
+
+      redis_url ->
+        # Parse REDIS_URL (Dokku pattern)
+        uri = URI.parse(redis_url)
+
+        base_config = [
+          host: uri.host || "localhost",
+          port: uri.port || 6379
+        ]
+
+        # Extract password from userinfo if present
+        case uri.userinfo do
+          nil ->
+            base_config
+
+          userinfo ->
+            # userinfo can be "password" or "username:password"
+            password =
+              case String.split(userinfo, ":", parts: 2) do
+                [pass] -> pass
+                [_user, pass] -> pass
+              end
+
+            Keyword.put(base_config, :password, password)
+        end
     end
 
   # Configure SSL options based on environment variables