From 6ad739a53cac0bbd761ab0cde6db76ab6e41e915 Mon Sep 17 00:00:00 2001
From: peaklabs-dev <122374094+peaklabs-dev@users.noreply.github.com>
Date: Wed, 9 Sep 2026 14:41:44 +0200
Subject: [PATCH] feat(docker): limit container name prefixes to 30 characters

---
 app/Livewire/Project/Application/Advanced.php               | 2 +-
 app/Models/ApplicationSetting.php                           | 6 ++++++
 bootstrap/helpers/api.php                                   | 3 ++-
 .../views/livewire/project/application/advanced.blade.php   | 2 +-
 4 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/app/Livewire/Project/Application/Advanced.php b/app/Livewire/Project/Application/Advanced.php
index b3564df0bb..a57d529bcb 100644
--- a/app/Livewire/Project/Application/Advanced.php
+++ b/app/Livewire/Project/Application/Advanced.php
@@ -70,7 +70,7 @@ class Advanced extends Component
     #[Validate(['string', 'nullable'])]
     public ?string $customInternalName = null;
 
-    #[Validate(['string', 'nullable', 'max:47'])]
+    #[Validate(['string', 'nullable', 'max:'.ApplicationSetting::MAX_CONTAINER_NAME_PREFIX_LENGTH])]
     public ?string $customContainerNamePrefix = null;
 
     #[Validate(['boolean'])]
diff --git a/app/Models/ApplicationSetting.php b/app/Models/ApplicationSetting.php
index 60fb9b2336..18b26f454f 100644
--- a/app/Models/ApplicationSetting.php
+++ b/app/Models/ApplicationSetting.php
@@ -50,6 +50,12 @@ use OpenApi\Attributes as OA;
 )]
 class ApplicationSetting extends Model
 {
+    /**
+     * Keeps generated names (prefix, timestamp and for compose apps the service name) well below the
+     * 63 character DNS label limit, with room for a longer suffix in the future.
+     */
+    public const MAX_CONTAINER_NAME_PREFIX_LENGTH = 30;
+
     protected $casts = [
         'is_static' => 'boolean',
         'is_spa' => 'boolean',
diff --git a/bootstrap/helpers/api.php b/bootstrap/helpers/api.php
index 81676ab070..b32870a5f7 100644
--- a/bootstrap/helpers/api.php
+++ b/bootstrap/helpers/api.php
@@ -4,6 +4,7 @@ use App\Actions\Shared\MigrateResourceToDestination;
 use App\Enums\BuildPackTypes;
 use App\Enums\RedirectTypes;
 use App\Enums\StaticImageTypes;
+use App\Models\ApplicationSetting;
 use App\Models\Environment;
 use App\Models\StandaloneDocker;
 use App\Models\SwarmDocker;
@@ -141,7 +142,7 @@ function sharedDataApplications()
         'gpu_options' => 'string|nullable',
         'is_consistent_container_name_enabled' => 'boolean',
         'custom_internal_name' => 'string|nullable',
-        'custom_container_name_prefix' => 'string|nullable|max:47',
+        'custom_container_name_prefix' => 'string|nullable|max:'.ApplicationSetting::MAX_CONTAINER_NAME_PREFIX_LENGTH,
         'preview_url_template' => 'string',
         'max_restart_count' => 'integer|min:0',
         'stop_grace_period' => 'nullable|integer|min:'.MIN_STOP_GRACE_PERIOD_SECONDS.'|max:'.MAX_STOP_GRACE_PERIOD_SECONDS,
diff --git a/resources/views/livewire/project/application/advanced.blade.php b/resources/views/livewire/project/application/advanced.blade.php
index 3a5549e0ea..27b40546bb 100644
--- a/resources/views/livewire/project/application/advanced.blade.php
+++ b/resources/views/livewire/project/application/advanced.blade.php
@@ -56,7 +56,7 @@
                     <form wire:submit="saveCustomNamePrefix" class="w-full">
                         <x-unsaved-bar action="saveCustomNamePrefix" targets="customContainerNamePrefix" />
                         <x-forms.input
-                            helper="Optional prefix for generated container names. Containers are named <span class='font-bold'>prefix-timestamp</span>, for example <span class='font-bold'>shop-api-20260908T141530</span>, instead of starting with <span class='font-bold'>{{ $application->uuid }}</span>.<br><br>The prefix is converted to slug format when saved, can be up to 47 characters and must be unique on this server. Rolling updates keep working."
+                            helper="Optional prefix for generated container names. Containers are named <span class='font-bold'>prefix-timestamp</span>, for example <span class='font-bold'>shop-api-20260908T141530</span>, instead of starting with <span class='font-bold'>{{ $application->uuid }}</span>.<br><br>The prefix is converted to slug format when saved, can be up to {{ \App\Models\ApplicationSetting::MAX_CONTAINER_NAME_PREFIX_LENGTH }} characters and must be unique on this server. Rolling updates keep working."
                             id="customContainerNamePrefix" label="Container name prefix" placeholder="e.g. my-api"
                             canGate="update" :canResource="$application" />
                     </form>