feat(deployments): track application configuration diffs

Store deployment configuration snapshots on application deployment queues and compare them against the current application state. Surface grouped pending changes in the configuration checker and use build-impact diffs to decide when an existing image can skip the build step.

app/Jobs/ApplicationDeploymentJob.php

@@ -537,11 +537,6 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
             \Log::warning('Post deployment command failed for '.$this->deployment_uuid.': '.$e->getMessage());
         }
 
-        try {
-            $this->application->isConfigurationChanged(true);
-        } catch (Exception $e) {
-            \Log::warning('Failed to mark configuration as changed for deployment '.$this->deployment_uuid.': '.$e->getMessage());
-        }
     }
 
     private function deploy_simple_dockerfile()
@@ -1238,8 +1233,9 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
 
                 return true;
             }
-            if (! $this->application->isConfigurationChanged()) {
-                $this->application_deployment_queue->addLogEntry("No configuration changed & image found ({$this->production_image_name}) with the same Git Commit SHA. Build step skipped.");
+            $configurationDiff = $this->application->pendingDeploymentConfigurationDiff();
+            if (! $configurationDiff->requiresBuild()) {
+                $this->application_deployment_queue->addLogEntry("No build configuration changed & image found ({$this->production_image_name}) with the same Git Commit SHA. Build step skipped.");
                 $this->skip_build = true;
                 $this->generate_compose_file();
 
@@ -1251,7 +1247,7 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
 
                 return true;
             } else {
-                $this->application_deployment_queue->addLogEntry('Configuration changed. Rebuilding image.');
+                $this->application_deployment_queue->addLogEntry('Build configuration changed. Rebuilding image.');
             }
         } else {
             $this->application_deployment_queue->addLogEntry("Image not found ({$this->production_image_name}). Building new image.");
@@ -4738,6 +4734,12 @@ COPY ./nginx.conf /etc/nginx/conf.d/default.conf");
             'last_restart_type' => null,
         ]);
 
+        try {
+            $this->application->markDeploymentConfigurationApplied($this->application_deployment_queue);
+        } catch (Exception $e) {
+            \Log::warning('Failed to mark configuration as applied for deployment '.$this->deployment_uuid.': '.$e->getMessage());
+        }
+
         event(new ApplicationConfigurationChanged($this->application->team()->id));
 
         if (! $this->only_this_server) {

app/Livewire/Project/Shared/ConfigurationChecker.php

@@ -18,6 +18,10 @@ class ConfigurationChecker extends Component
 {
     public bool $isConfigurationChanged = false;
 
+    public array $configurationDiff = [];
+
+    public array $groupedConfigurationChanges = [];
+
     public Application|Service|StandaloneRedis|StandalonePostgresql|StandaloneMongodb|StandaloneMysql|StandaloneMariadb|StandaloneKeydb|StandaloneDragonfly|StandaloneClickhouse $resource;
 
     public function getListeners()
@@ -42,6 +46,17 @@ class ConfigurationChecker extends Component
 
     public function configurationChanged()
     {
+        if ($this->resource instanceof Application) {
+            $diff = $this->resource->pendingDeploymentConfigurationDiff();
+            $this->isConfigurationChanged = $diff->isChanged();
+            $this->configurationDiff = $diff->toArray();
+            $this->groupedConfigurationChanges = $diff->groupedChanges();
+
+            return;
+        }
+
         $this->isConfigurationChanged = $this->resource->isConfigurationChanged();
+        $this->configurationDiff = [];
+        $this->groupedConfigurationChanges = [];
     }
 }

app/Models/Application.php

@@ -4,6 +4,9 @@ namespace App\Models;
 
 use App\Enums\ApplicationDeploymentStatus;
 use App\Services\ConfigurationGenerator;
+use App\Services\DeploymentConfiguration\ApplicationConfigurationSnapshot;
+use App\Services\DeploymentConfiguration\ConfigurationDiff;
+use App\Services\DeploymentConfiguration\ConfigurationDiffer;
 use App\Traits\ClearsGlobalSearchCache;
 use App\Traits\HasConfiguration;
 use App\Traits\HasMetrics;
@@ -720,14 +723,14 @@ class Application extends BaseModel
         return Attribute::make(
             set: function ($value) {
                 if (is_null($value) || $value === '') {
-                    return '/Dockerfile';
-                } else {
-                    if ($value !== '/') {
-                        return Str::start(Str::replaceEnd('/', '', $value), '/');
-                    }
-
-                    return Str::start($value, '/');
+                    return $this->build_pack === 'dockerfile' ? '/Dockerfile' : null;
                 }
+
+                if ($value !== '/') {
+                    return Str::start(Str::replaceEnd('/', '', $value), '/');
+                }
+
+                return Str::start($value, '/');
             }
         );
     }
@@ -1059,7 +1062,7 @@ class Application extends BaseModel
 
     public function get_last_successful_deployment()
     {
-        return ApplicationDeploymentQueue::where('application_id', $this->id)->where('status', ApplicationDeploymentStatus::FINISHED)->where('pull_request_id', 0)->orderBy('created_at', 'desc')->first();
+        return ApplicationDeploymentQueue::where('application_id', $this->id)->where('status', ApplicationDeploymentStatus::FINISHED->value)->where('pull_request_id', 0)->orderBy('created_at', 'desc')->first();
     }
 
     public function get_last_days_deployments()
@@ -1170,6 +1173,83 @@ class Application extends BaseModel
     }
 
     public function isConfigurationChanged(bool $save = false)
+    {
+        $configurationDiff = $this->pendingDeploymentConfigurationDiff();
+
+        if ($save) {
+            $this->markDeploymentConfigurationApplied();
+        }
+
+        return $configurationDiff->isChanged();
+    }
+
+    public function pendingDeploymentConfigurationDiff(): ConfigurationDiff
+    {
+        $currentSnapshot = $this->deploymentConfigurationSnapshot();
+        $lastDeployment = $this->get_last_successful_deployment();
+
+        if ($lastDeployment?->configuration_snapshot) {
+            return app(ConfigurationDiffer::class)->diff($lastDeployment->configuration_snapshot, $currentSnapshot);
+        }
+
+        $oldConfigHash = data_get($this, 'config_hash');
+
+        if ($oldConfigHash === null) {
+            return ConfigurationDiff::legacy(true);
+        }
+
+        return ConfigurationDiff::legacy($oldConfigHash !== $this->legacyConfigurationHash());
+    }
+
+    public function hasPendingDeploymentConfigurationChanges(): bool
+    {
+        return $this->pendingDeploymentConfigurationDiff()->isChanged();
+    }
+
+    public function deploymentConfigurationSnapshot(): array
+    {
+        return (new ApplicationConfigurationSnapshot($this))->toArray();
+    }
+
+    public function deploymentConfigurationHash(): string
+    {
+        return ApplicationConfigurationSnapshot::hashSnapshot($this->deploymentConfigurationSnapshot());
+    }
+
+    public function markDeploymentConfigurationApplied(?ApplicationDeploymentQueue $deployment = null): void
+    {
+        $this->refresh();
+
+        if (! $deployment) {
+            $this->forceFill(['config_hash' => $this->legacyConfigurationHash()])->save();
+
+            return;
+        }
+
+        $snapshot = $this->deploymentConfigurationSnapshot();
+        $hash = ApplicationConfigurationSnapshot::hashSnapshot($snapshot);
+
+        $previousDeployment = ApplicationDeploymentQueue::query()
+            ->where('application_id', $this->id)
+            ->where('status', ApplicationDeploymentStatus::FINISHED->value)
+            ->where('pull_request_id', $deployment->pull_request_id ?? 0)
+            ->where('id', '!=', $deployment->id)
+            ->whereNotNull('configuration_snapshot')
+            ->latest()
+            ->first();
+
+        $deployment->update([
+            'configuration_hash' => $hash,
+            'configuration_snapshot' => $snapshot,
+            'configuration_diff' => $previousDeployment?->configuration_snapshot
+                ? app(ConfigurationDiffer::class)->diff($previousDeployment->configuration_snapshot, $snapshot)->toArray()
+                : null,
+        ]);
+
+        $this->forceFill(['config_hash' => $hash])->save();
+    }
+
+    private function legacyConfigurationHash(): string
     {
         $newConfigHash = base64_encode($this->fqdn.$this->git_repository.$this->git_branch.$this->git_commit_sha.$this->build_pack.$this->static_image.$this->install_command.$this->build_command.$this->start_command.$this->ports_exposes.$this->ports_mappings.$this->custom_network_aliases.$this->base_directory.$this->publish_directory.$this->dockerfile.$this->dockerfile_location.$this->custom_labels.$this->custom_docker_run_options.$this->dockerfile_target_build.$this->redirect.$this->custom_nginx_configuration.$this->settings?->use_build_secrets.$this->settings?->inject_build_args_to_dockerfile.$this->settings?->include_source_commit_in_build);
         if ($this->pull_request_id === 0 || $this->pull_request_id === null) {
@@ -1177,26 +1257,8 @@ class Application extends BaseModel
         } else {
             $newConfigHash .= json_encode($this->environment_variables_preview->get(['value',  'is_multiline', 'is_literal', 'is_buildtime', 'is_runtime'])->sort());
         }
-        $newConfigHash = md5($newConfigHash);
-        $oldConfigHash = data_get($this, 'config_hash');
-        if ($oldConfigHash === null) {
-            if ($save) {
-                $this->config_hash = $newConfigHash;
-                $this->save();
-            }
 
-            return true;
-        }
-        if ($oldConfigHash === $newConfigHash) {
-            return false;
-        } else {
-            if ($save) {
-                $this->config_hash = $newConfigHash;
-                $this->save();
-            }
-
-            return true;
-        }
+        return md5($newConfigHash);
     }
 
     public function customRepository()

app/Models/ApplicationDeploymentQueue.php

@@ -17,6 +17,9 @@ use OpenApi\Attributes as OA;
         'deployment_uuid' => ['type' => 'string'],
         'pull_request_id' => ['type' => 'integer'],
         'docker_registry_image_tag' => ['type' => 'string', 'nullable' => true],
+        'configuration_hash' => ['type' => 'string', 'nullable' => true],
+        'configuration_snapshot' => ['type' => 'object', 'nullable' => true],
+        'configuration_diff' => ['type' => 'object', 'nullable' => true],
         'force_rebuild' => ['type' => 'boolean'],
         'commit' => ['type' => 'string'],
         'status' => ['type' => 'string'],
@@ -45,6 +48,9 @@ class ApplicationDeploymentQueue extends Model
         'deployment_uuid',
         'pull_request_id',
         'docker_registry_image_tag',
+        'configuration_hash',
+        'configuration_snapshot',
+        'configuration_diff',
         'force_rebuild',
         'commit',
         'status',
@@ -71,6 +77,8 @@ class ApplicationDeploymentQueue extends Model
     protected $casts = [
         'pull_request_id' => 'integer',
         'finished_at' => 'datetime',
+        'configuration_snapshot' => 'array',
+        'configuration_diff' => 'array',
     ];
 
     public function application()

app/Services/DeploymentConfiguration/ApplicationConfigurationSnapshot.php

@@ -0,0 +1,338 @@
+<?php
+
+namespace App\Services\DeploymentConfiguration;
+
+use App\Models\Application;
+use App\Models\EnvironmentVariable;
+use Illuminate\Support\Arr;
+
+class ApplicationConfigurationSnapshot
+{
+    public const SCHEMA_VERSION = 1;
+
+    public function __construct(protected Application $application) {}
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function toArray(): array
+    {
+        $this->application->load('settings');
+
+        return [
+            'schema_version' => self::SCHEMA_VERSION,
+            'resource_type' => Application::class,
+            'resource_id' => $this->application->id,
+            'sections' => [
+                'source' => [
+                    'label' => 'Source',
+                    'items' => $this->sourceItems(),
+                ],
+                'build' => [
+                    'label' => 'Build',
+                    'items' => $this->buildItems(),
+                ],
+                'runtime' => [
+                    'label' => 'Runtime',
+                    'items' => $this->runtimeItems(),
+                ],
+                'domains' => [
+                    'label' => 'Domains & Proxy',
+                    'items' => $this->domainItems(),
+                ],
+                'environment' => [
+                    'label' => 'Environment Variables',
+                    'items' => $this->environmentItems(),
+                ],
+            ],
+        ];
+    }
+
+    public function hash(): string
+    {
+        return self::hashSnapshot($this->toArray());
+    }
+
+    /**
+     * @param  array<string, mixed>  $snapshot
+     */
+    public static function hashSnapshot(array $snapshot): string
+    {
+        return hash('sha256', json_encode(self::comparableSnapshot($snapshot), JSON_THROW_ON_ERROR));
+    }
+
+    /**
+     * @param  array<string, mixed>  $snapshot
+     * @return array<string, mixed>
+     */
+    public static function comparableSnapshot(array $snapshot): array
+    {
+        $sections = collect(data_get($snapshot, 'sections', []))
+            ->mapWithKeys(function (array $section, string $sectionKey): array {
+                $items = collect(data_get($section, 'items', []))
+                    ->mapWithKeys(fn (array $item): array => [
+                        $item['key'] => [
+                            'compare_value' => $item['compare_value'] ?? null,
+                            'impact' => $item['impact'] ?? 'redeploy',
+                        ],
+                    ])
+                    ->sortKeys()
+                    ->all();
+
+                return [$sectionKey => $items];
+            })
+            ->sortKeys()
+            ->all();
+
+        return [
+            'schema_version' => data_get($snapshot, 'schema_version'),
+            'sections' => $sections,
+        ];
+    }
+
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    private function sourceItems(): array
+    {
+        return [
+            $this->item('git_repository', 'Repository', $this->application->git_repository, 'build'),
+            $this->item('git_branch', 'Branch', $this->application->git_branch, 'build'),
+            $this->item('git_commit_sha', 'Commit SHA', $this->application->git_commit_sha, 'build'),
+            $this->item('private_key_id', 'Private key', $this->application->private_key_id, 'build'),
+        ];
+    }
+
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    private function buildItems(): array
+    {
+        return [
+            $this->item('build_pack', 'Build pack', $this->application->build_pack, 'build'),
+            $this->item('static_image', 'Static image', $this->application->static_image, 'build'),
+            $this->item('base_directory', 'Base directory', $this->application->base_directory, 'build'),
+            $this->item('publish_directory', 'Publish directory', $this->application->publish_directory, 'build'),
+            $this->item('install_command', 'Install command', $this->application->install_command, 'build'),
+            $this->item('build_command', 'Build command', $this->application->build_command, 'build'),
+            $this->item('dockerfile', 'Dockerfile', $this->application->dockerfile, 'build', displayValue: $this->summarizeText($this->application->dockerfile)),
+            $this->item('dockerfile_location', 'Dockerfile location', $this->application->dockerfile_location, 'build'),
+            $this->item('dockerfile_target_build', 'Dockerfile target', $this->application->dockerfile_target_build, 'build'),
+            $this->item('docker_compose_location', 'Docker Compose location', $this->application->docker_compose_location, 'build'),
+            $this->item('docker_compose', 'Docker Compose', $this->application->docker_compose, 'build', displayValue: $this->summarizeText($this->application->docker_compose)),
+            $this->item('docker_compose_raw', 'Raw Docker Compose', $this->application->docker_compose_raw, 'build', displayValue: $this->summarizeText($this->application->docker_compose_raw)),
+            $this->item('docker_compose_custom_build_command', 'Docker Compose custom build command', $this->application->docker_compose_custom_build_command, 'build'),
+            $this->item('custom_docker_run_options', 'Custom Docker run options', $this->application->custom_docker_run_options, 'build'),
+            $this->item('use_build_secrets', 'Use build secrets', data_get($this->application, 'settings.use_build_secrets'), 'build'),
+            $this->item('inject_build_args_to_dockerfile', 'Inject build args to Dockerfile', data_get($this->application, 'settings.inject_build_args_to_dockerfile'), 'build'),
+            $this->item('include_source_commit_in_build', 'Include source commit in build', data_get($this->application, 'settings.include_source_commit_in_build'), 'build'),
+            $this->item('disable_build_cache', 'Disable build cache', data_get($this->application, 'settings.disable_build_cache'), 'build'),
+            $this->item('is_build_server_enabled', 'Build server', data_get($this->application, 'settings.is_build_server_enabled'), 'build'),
+        ];
+    }
+
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    private function runtimeItems(): array
+    {
+        return [
+            $this->item('start_command', 'Start command', $this->application->start_command, 'redeploy'),
+            $this->item('docker_compose_custom_start_command', 'Docker Compose custom start command', $this->application->docker_compose_custom_start_command, 'redeploy'),
+            $this->item('ports_exposes', 'Exposed ports', $this->application->ports_exposes, 'redeploy'),
+            $this->item('ports_mappings', 'Port mappings', $this->application->ports_mappings, 'redeploy'),
+            $this->item('custom_network_aliases', 'Network aliases', $this->application->custom_network_aliases, 'redeploy'),
+            $this->item('connect_to_docker_network', 'Connect to Docker network', data_get($this->application, 'settings.connect_to_docker_network'), 'redeploy'),
+            $this->item('custom_internal_name', 'Custom container name', data_get($this->application, 'settings.custom_internal_name'), 'redeploy'),
+            $this->item('is_raw_compose_deployment_enabled', 'Raw Compose deployment', data_get($this->application, 'settings.is_raw_compose_deployment_enabled'), 'redeploy'),
+            $this->item('is_gpu_enabled', 'GPU enabled', data_get($this->application, 'settings.is_gpu_enabled'), 'redeploy'),
+            $this->item('gpu_driver', 'GPU driver', data_get($this->application, 'settings.gpu_driver'), 'redeploy'),
+            $this->item('gpu_count', 'GPU count', data_get($this->application, 'settings.gpu_count'), 'redeploy'),
+            $this->item('gpu_device_ids', 'GPU device IDs', data_get($this->application, 'settings.gpu_device_ids'), 'redeploy'),
+            $this->item('gpu_options', 'GPU options', data_get($this->application, 'settings.gpu_options'), 'redeploy'),
+            ...$this->healthCheckItems(),
+            ...$this->limitItems(),
+        ];
+    }
+
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    private function domainItems(): array
+    {
+        return [
+            $this->item('fqdn', 'Domains', $this->application->fqdn, 'redeploy'),
+            $this->item('redirect', 'Redirect', $this->application->redirect, 'redeploy'),
+            $this->item('custom_labels', 'Container labels', $this->application->custom_labels, 'redeploy', displayValue: $this->summarizeText($this->application->custom_labels)),
+            $this->item('custom_nginx_configuration', 'Custom Nginx configuration', $this->application->custom_nginx_configuration, 'redeploy', displayValue: $this->summarizeText($this->application->custom_nginx_configuration)),
+            $this->item('is_force_https_enabled', 'Force HTTPS', data_get($this->application, 'settings.is_force_https_enabled'), 'redeploy'),
+            $this->item('is_gzip_enabled', 'Gzip', data_get($this->application, 'settings.is_gzip_enabled'), 'redeploy'),
+            $this->item('is_stripprefix_enabled', 'Strip prefix', data_get($this->application, 'settings.is_stripprefix_enabled'), 'redeploy'),
+            $this->item('is_http_basic_auth_enabled', 'HTTP basic auth', $this->application->is_http_basic_auth_enabled, 'redeploy'),
+            $this->item('http_basic_auth_username', 'HTTP basic auth username', $this->application->http_basic_auth_username, 'redeploy'),
+            $this->item('http_basic_auth_password', 'HTTP basic auth password', $this->application->http_basic_auth_password, 'redeploy', sensitive: true),
+        ];
+    }
+
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    private function environmentItems(): array
+    {
+        return $this->application->environment_variables()
+            ->get()
+            ->sortBy('key', SORT_NATURAL | SORT_FLAG_CASE)
+            ->values()
+            ->map(fn (EnvironmentVariable $environmentVariable): array => $this->environmentItem($environmentVariable))
+            ->all();
+    }
+
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    private function healthCheckItems(): array
+    {
+        return collect([
+            'health_check_enabled' => 'Health check enabled',
+            'health_check_path' => 'Health check path',
+            'health_check_port' => 'Health check port',
+            'health_check_host' => 'Health check host',
+            'health_check_method' => 'Health check method',
+            'health_check_return_code' => 'Health check return code',
+            'health_check_scheme' => 'Health check scheme',
+            'health_check_response_text' => 'Health check response text',
+            'health_check_interval' => 'Health check interval',
+            'health_check_timeout' => 'Health check timeout',
+            'health_check_retries' => 'Health check retries',
+            'health_check_start_period' => 'Health check start period',
+            'health_check_type' => 'Health check type',
+            'health_check_command' => 'Health check command',
+        ])->map(fn (string $label, string $key): array => $this->item($key, $label, data_get($this->application, $key), 'redeploy'))->values()->all();
+    }
+
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    private function limitItems(): array
+    {
+        return collect([
+            'limits_memory' => 'Memory limit',
+            'limits_memory_swap' => 'Memory swap limit',
+            'limits_memory_swappiness' => 'Memory swappiness',
+            'limits_memory_reservation' => 'Memory reservation',
+            'limits_cpus' => 'CPU limit',
+            'limits_cpuset' => 'CPU set',
+            'limits_cpu_shares' => 'CPU shares',
+            'swarm_replicas' => 'Swarm replicas',
+            'swarm_placement_constraints' => 'Swarm placement constraints',
+        ])->map(fn (string $label, string $key): array => $this->item($key, $label, data_get($this->application, $key), 'redeploy'))->values()->all();
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    private function environmentItem(EnvironmentVariable $environmentVariable): array
+    {
+        $impact = $environmentVariable->is_buildtime ? 'build' : 'redeploy';
+        $compareValue = [
+            'value_hash' => $this->sensitiveHash($environmentVariable->value),
+            'is_multiline' => $environmentVariable->is_multiline,
+            'is_literal' => $environmentVariable->is_literal,
+            'is_buildtime' => $environmentVariable->is_buildtime,
+            'is_runtime' => $environmentVariable->is_runtime,
+        ];
+
+        return $this->item(
+            key: (string) $environmentVariable->key,
+            label: (string) $environmentVariable->key,
+            value: $compareValue,
+            impact: $impact,
+            sensitive: true,
+            displayValue: $this->environmentDisplayValue($environmentVariable),
+        );
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    private function item(string $key, string $label, mixed $value, string $impact, bool $sensitive = false, mixed $displayValue = null): array
+    {
+        $normalizedValue = $this->normalizeValue($value);
+
+        return [
+            'key' => $key,
+            'label' => $label,
+            'impact' => $impact,
+            'sensitive' => $sensitive,
+            'compare_value' => $sensitive ? $this->sensitiveHash($normalizedValue) : $normalizedValue,
+            'display_value' => $displayValue ?? $this->displayValue($normalizedValue),
+        ];
+    }
+
+    private function environmentDisplayValue(EnvironmentVariable $environmentVariable): string
+    {
+        $flags = collect([
+            $environmentVariable->is_buildtime ? 'build-time' : null,
+            $environmentVariable->is_runtime ? 'runtime' : null,
+            $environmentVariable->is_multiline ? 'multiline' : null,
+            $environmentVariable->is_literal ? 'literal' : null,
+        ])->filter()->implode(', ');
+
+        return $flags ? "Hidden ({$flags})" : 'Hidden';
+    }
+
+    private function sensitiveHash(mixed $value): string
+    {
+        return hash_hmac('sha256', json_encode($value, JSON_THROW_ON_ERROR), (string) config('app.key', 'coolify'));
+    }
+
+    private function normalizeValue(mixed $value): mixed
+    {
+        if ($value === '') {
+            return null;
+        }
+
+        if (is_bool($value) || is_numeric($value) || $value === null || is_string($value)) {
+            return $value;
+        }
+
+        if (is_array($value)) {
+            return Arr::sortRecursive($value);
+        }
+
+        return (string) $value;
+    }
+
+    private function displayValue(mixed $value): string
+    {
+        if ($value === null) {
+            return 'Not set';
+        }
+
+        if (is_bool($value)) {
+            return $value ? 'Enabled' : 'Disabled';
+        }
+
+        if (is_array($value)) {
+            return $this->summarizeText(json_encode($value, JSON_THROW_ON_ERROR));
+        }
+
+        return $this->summarizeText((string) $value);
+    }
+
+    private function summarizeText(?string $value): string
+    {
+        if (blank($value)) {
+            return 'Not set';
+        }
+
+        $value = trim((string) $value);
+        $lines = substr_count($value, "\n") + 1;
+
+        if ($lines > 1) {
+            return str($value)->limit(80)." ({$lines} lines)";
+        }
+
+        return str($value)->limit(120)->value();
+    }
+}

app/Services/DeploymentConfiguration/ConfigurationDiff.php

@@ -0,0 +1,112 @@
+<?php
+
+namespace App\Services\DeploymentConfiguration;
+
+use Illuminate\Support\Collection;
+
+class ConfigurationDiff
+{
+    /**
+     * @param  array<int, array<string, mixed>>  $changes
+     */
+    public function __construct(
+        protected array $changes = [],
+        protected bool $legacyFallback = false,
+    ) {}
+
+    public static function unchanged(): self
+    {
+        return new self;
+    }
+
+    public static function legacy(bool $changed): self
+    {
+        if (! $changed) {
+            return self::unchanged();
+        }
+
+        return new self([
+            [
+                'key' => 'legacy.configuration',
+                'section' => 'configuration',
+                'section_label' => 'Configuration',
+                'label' => 'Configuration',
+                'type' => 'changed',
+                'impact' => 'build',
+                'sensitive' => false,
+                'old_display_value' => 'Previously deployed configuration',
+                'new_display_value' => 'Current configuration',
+            ],
+        ], true);
+    }
+
+    /**
+     * @param  array<int, array<string, mixed>>  $changes
+     */
+    public static function fromChanges(array $changes): self
+    {
+        return new self(array_values($changes));
+    }
+
+    public function isChanged(): bool
+    {
+        return $this->changes !== [];
+    }
+
+    public function isLegacyFallback(): bool
+    {
+        return $this->legacyFallback;
+    }
+
+    public function count(): int
+    {
+        return count($this->changes);
+    }
+
+    public function requiresBuild(): bool
+    {
+        return collect($this->changes)->contains(fn (array $change): bool => $change['impact'] === 'build');
+    }
+
+    public function requiresRedeploy(): bool
+    {
+        return $this->isChanged();
+    }
+
+    /**
+     * @return array<int, array<string, mixed>>
+     */
+    public function changes(): array
+    {
+        return $this->changes;
+    }
+
+    /**
+     * @return array<string, array{label: string, changes: array<int, array<string, mixed>>}>
+     */
+    public function groupedChanges(): array
+    {
+        return collect($this->changes)
+            ->groupBy('section')
+            ->map(fn (Collection $changes): array => [
+                'label' => (string) data_get($changes->first(), 'section_label', str((string) $changes->keys()->first())->headline()),
+                'changes' => $changes->values()->all(),
+            ])
+            ->all();
+    }
+
+    /**
+     * @return array{changed: bool, count: int, requires_build: bool, requires_redeploy: bool, legacy_fallback: bool, changes: array<int, array<string, mixed>>}
+     */
+    public function toArray(): array
+    {
+        return [
+            'changed' => $this->isChanged(),
+            'count' => $this->count(),
+            'requires_build' => $this->requiresBuild(),
+            'requires_redeploy' => $this->requiresRedeploy(),
+            'legacy_fallback' => $this->isLegacyFallback(),
+            'changes' => $this->changes(),
+        ];
+    }
+}

app/Services/DeploymentConfiguration/ConfigurationDiffer.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace App\Services\DeploymentConfiguration;
+
+class ConfigurationDiffer
+{
+    /**
+     * @param  array<string, mixed>  $previousSnapshot
+     * @param  array<string, mixed>  $currentSnapshot
+     */
+    public function diff(array $previousSnapshot, array $currentSnapshot): ConfigurationDiff
+    {
+        $previousItems = $this->flattenItems($previousSnapshot);
+        $currentItems = $this->flattenItems($currentSnapshot);
+        $keys = collect(array_keys($previousItems))->merge(array_keys($currentItems))->unique()->sort();
+        $changes = [];
+
+        foreach ($keys as $key) {
+            $previous = $previousItems[$key] ?? null;
+            $current = $currentItems[$key] ?? null;
+
+            if (($previous['compare_value'] ?? null) === ($current['compare_value'] ?? null)) {
+                continue;
+            }
+
+            $item = $current ?? $previous;
+            $sensitive = (bool) data_get($item, 'sensitive', false);
+            $type = $previous === null ? 'added' : ($current === null ? 'removed' : 'changed');
+            $displaySummary = $sensitive && $type === 'changed' ? 'Changed' : null;
+
+            $changes[] = [
+                'key' => $key,
+                'section' => data_get($item, 'section'),
+                'section_label' => data_get($item, 'section_label'),
+                'label' => data_get($item, 'label'),
+                'type' => $type,
+                'impact' => data_get($item, 'impact', 'redeploy'),
+                'sensitive' => $sensitive,
+                'display_summary' => $displaySummary,
+                'old_display_value' => $sensitive ? ($previous === null ? 'Not set' : 'Set') : data_get($previous, 'display_value', 'Not set'),
+                'new_display_value' => $sensitive ? ($current === null ? 'Removed' : 'Set') : data_get($current, 'display_value', 'Not set'),
+            ];
+        }
+
+        return ConfigurationDiff::fromChanges($changes);
+    }
+
+    /**
+     * @param  array<string, mixed>  $snapshot
+     * @return array<string, array<string, mixed>>
+     */
+    private function flattenItems(array $snapshot): array
+    {
+        return collect(data_get($snapshot, 'sections', []))
+            ->flatMap(function (array $section, string $sectionKey): array {
+                return collect(data_get($section, 'items', []))
+                    ->mapWithKeys(function (array $item) use ($section, $sectionKey): array {
+                        $key = $sectionKey.'.'.$item['key'];
+
+                        return [$key => array_merge($item, [
+                            'section' => $sectionKey,
+                            'section_label' => data_get($section, 'label', str($sectionKey)->headline()->value()),
+                        ])];
+                    })
+                    ->all();
+            })
+            ->all();
+    }
+}