fix(previews): keep custom preview domains on redeploy

Closes #6536

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Jobs/ApplicationDeploymentJob.php

@@ -292,9 +292,9 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
             }
             if ($this->preview) {
                 if ($this->application->build_pack === 'dockercompose') {
-                    $this->preview->generate_preview_fqdn_compose();
+                    $this->preview->generate_preview_fqdn_compose(keepExistingDomains: true);
                 } else {
-                    $this->preview->generate_preview_fqdn();
+                    $this->preview->generate_preview_fqdn(keepExistingDomains: true);
                 }
             }
             if ($this->application->isGithubAppSource()) {

app/Livewire/Project/Application/Previews.php

@@ -147,7 +147,7 @@ class Previews extends Component
                     ]);
                     $this->auditPreviewEvent('ui.application.preview_created', $pull_request_id);
                 }
-                $found->generate_preview_fqdn_compose();
+                $found->generate_preview_fqdn_compose(keepExistingDomains: ! $found->wasRecentlyCreated);
                 $this->application->refresh();
                 $this->syncDockerTags();
             } else {
@@ -165,7 +165,7 @@ class Previews extends Component
                 if ($found && $this->application->build_pack === 'dockerimage' && str($docker_registry_image_tag)->isNotEmpty()) {
                     $this->saveDockerTagWithAudit($found, $docker_registry_image_tag);
                 }
-                $found->generate_preview_fqdn(generateWithoutApplicationDomain: true);
+                $found->generate_preview_fqdn(generateWithoutApplicationDomain: true, keepExistingDomains: true);
                 $this->application->refresh();
                 $this->syncDockerTags();
                 $this->dispatch('update_links');

app/Models/ApplicationPreview.php

@@ -196,8 +196,23 @@ class ApplicationPreview extends BaseModel
         return $this->morphMany(LocalPersistentVolume::class, 'resource');
     }
 
-    public function generate_preview_fqdn(bool $generateWithoutApplicationDomain = false)
+    /**
+     * Set the preview domains from the preview URL template.
+     *
+     * With $keepExistingDomains, domains already stored on the preview (for example custom
+     * domains set in the UI) are kept, and only an empty preview gets generated domains.
+     */
+    public function generate_preview_fqdn(bool $generateWithoutApplicationDomain = false, bool $keepExistingDomains = false)
     {
+        if ($keepExistingDomains && filled($this->fqdn)) {
+            $normalized = DomainPortOverrides::normalize($this->fqdn, $this->domain_port_overrides);
+            $this->fqdn = $normalized['fqdn'];
+            $this->domain_port_overrides = $normalized['overrides'];
+            $this->save();
+
+            return $this;
+        }
+
         $applicationFqdn = $this->application->fqdn;
         if (! $applicationFqdn && $generateWithoutApplicationDomain) {
             $applicationFqdn = generateUrl(
@@ -221,7 +236,13 @@ class ApplicationPreview extends BaseModel
         return $this;
     }
 
-    public function generate_preview_fqdn_compose(bool $generateWithoutApplicationDomain = false)
+    /**
+     * Set the preview domain of every compose service from the preview URL template.
+     *
+     * With $keepExistingDomains, a service that already has domains on the preview keeps them,
+     * and only services without a preview domain get generated domains.
+     */
+    public function generate_preview_fqdn_compose(bool $generateWithoutApplicationDomain = false, bool $keepExistingDomains = false)
     {
         $applicationDomains = json_decode($this->application->docker_compose_domains ?: '[]', true) ?: [];
         $previewDomains = json_decode(data_get($this, 'docker_compose_domains') ?: '[]', true) ?: [];
@@ -262,6 +283,21 @@ class ApplicationPreview extends BaseModel
         $docker_compose_domains = [];
         $previewPortOverrides = [];
         foreach ($serviceNames as $service_name) {
+            $existingPreviewDomains = $keepExistingDomains
+                ? DomainPortOverrides::normalize(getComposeServiceDomainString($previewDomains, $service_name), $this->domain_port_overrides)
+                : ['fqdn' => null, 'overrides' => null];
+            if (filled($existingPreviewDomains['fqdn'])) {
+                $docker_compose_domains = putComposeServiceDomain(
+                    $docker_compose_domains,
+                    $service_name,
+                    $existingPreviewDomains['fqdn'],
+                    $serviceNames,
+                );
+                $previewPortOverrides = array_merge($previewPortOverrides, $existingPreviewDomains['overrides'] ?? []);
+
+                continue;
+            }
+
             $domain_string = getComposeServiceDomainString($applicationDomains, $service_name);
 
             if (empty($domain_string)) {

tests/Feature/PreviewDomainPortOverridesTest.php

@@ -1113,3 +1113,102 @@ it('does not queue file sync jobs when polling dns checks for compose previews',
         ->and(Queue::pushed(ServerFilesFromServerJob::class))->toHaveCount(1)
         ->and($component->get('composeServices'))->toBe(['web', 'api']);
 });
+
+it('keeps custom preview domains and port overrides on redeploy', function () {
+    $this->application->update([
+        'fqdn' => 'https://app.example.com',
+        'preview_url_template' => '{{pr_id}}.{{domain}}',
+    ]);
+    $preview = createPreviewForPortTests($this->application, 6536, [
+        'fqdn' => 'https://custom-one.example.com,https://custom-two.example.com',
+        'domain_port_overrides' => ['https://custom-two.example.com' => 9000],
+    ]);
+
+    // The deployment job keeps the stored preview domains.
+    $preview->fresh()->generate_preview_fqdn(keepExistingDomains: true);
+
+    expect($preview->fresh()->fqdn)->toBe('https://custom-one.example.com,https://custom-two.example.com')
+        ->and($preview->fresh()->domain_port_overrides)->toBe(['https://custom-two.example.com' => 9000]);
+
+    // Without the flag (the "Generate domain" action), the template replaces them.
+    $preview->fresh()->generate_preview_fqdn();
+
+    expect($preview->fresh()->fqdn)->toBe('https://6536.app.example.com')
+        ->and($preview->fresh()->domain_port_overrides)->toBeNull();
+});
+
+it('moves a port from a kept legacy preview domain into the overrides', function () {
+    $this->application->update(['fqdn' => 'https://app.example.com']);
+    $preview = createPreviewForPortTests($this->application, 6537, [
+        'fqdn' => 'https://custom.example.com:3000',
+    ]);
+
+    $preview->generate_preview_fqdn(keepExistingDomains: true);
+
+    expect($preview->fresh()->fqdn)->toBe('https://custom.example.com')
+        ->and($preview->fresh()->domain_port_overrides)->toBe(['https://custom.example.com' => 3000]);
+});
+
+it('generates a domain on redeploy when the preview has none', function () {
+    $this->application->update([
+        'fqdn' => 'https://app.example.com',
+        'preview_url_template' => '{{pr_id}}.{{domain}}',
+    ]);
+    $preview = createPreviewForPortTests($this->application, 6538);
+
+    $preview->generate_preview_fqdn(keepExistingDomains: true);
+
+    expect($preview->fresh()->fqdn)->toBe('https://6538.app.example.com');
+});
+
+it('keeps custom compose preview domains on redeploy and fills empty services', function () {
+    $this->application->update([
+        'build_pack' => 'dockercompose',
+        'preview_url_template' => '{{pr_id}}.{{domain}}',
+        'docker_compose_raw' => "services:\n  frontend:\n    image: nginx:alpine\n  backend:\n    image: nginx:alpine\n",
+        'docker_compose_domains' => json_encode([
+            'frontend' => ['domain' => 'https://app.example.com'],
+            'backend' => ['domain' => 'https://api.example.com:3001'],
+        ]),
+    ]);
+    $preview = createPreviewForPortTests($this->application->fresh(), 6539, [
+        'docker_compose_domains' => json_encode([
+            'frontend' => ['domain' => 'https://custom.example.com'],
+            'backend' => ['domain' => ''],
+        ]),
+        'domain_port_overrides' => ['https://custom.example.com' => 8080],
+    ]);
+
+    $preview->generate_preview_fqdn_compose(keepExistingDomains: true);
+    $preview->refresh();
+
+    expect(json_decode($preview->docker_compose_domains, true))->toBe([
+        'frontend' => ['domain' => 'https://custom.example.com'],
+        'backend' => ['domain' => 'https://6539.api.example.com'],
+    ])
+        ->and($preview->fqdn)->toBe('https://custom.example.com,https://6539.api.example.com')
+        ->and($preview->domain_port_overrides)->toBe([
+            'https://custom.example.com' => 8080,
+            'https://6539.api.example.com' => 3001,
+        ]);
+
+    $preview->generate_preview_fqdn_compose();
+
+    expect(json_decode($preview->fresh()->docker_compose_domains, true)['frontend']['domain'])->toBe('https://6539.app.example.com');
+});
+
+it('replaces a custom preview domain when the generate action runs', function () {
+    $this->application->update([
+        'fqdn' => 'https://app.example.com',
+        'preview_url_template' => '{{pr_id}}.{{domain}}',
+    ]);
+    $preview = createPreviewForPortTests($this->application, 6540, [
+        'fqdn' => 'https://custom.example.com',
+    ]);
+
+    Livewire::test(PreviewDomains::class, ['preview' => $preview])
+        ->call('generateDomain')
+        ->assertHasNoErrors();
+
+    expect($preview->fresh()->fqdn)->toBe('https://6540.app.example.com');
+});