Unify URL resolution, add health checker sync, and make modules optional

- Add url-resolver.js with single resolveServiceUrl() used by all 5 consumers
  (probes, health routes, health checker auto-config)
- Health checker now does full sync (add/update/remove) instead of add-only,
  and re-syncs automatically after every services.json mutation
- docker-maintenance and log-digest are now optional imports with try/catch,
  preventing container crashes when these files are absent
- Add null guards in routes/logs.js for graceful 503 responses

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

dashcaddy-api/routes/context.js

@@ -111,10 +111,12 @@ const ctx = {
   logError: null,
   safeErrorMessage: null,
   buildDomain: null,
+  buildServiceUrl: null,
   getServiceById: null,
   readConfig: null,
   saveConfig: null,
   addServiceToConfig: null,
+  resyncHealthChecker: null,
   validateURL: null,
 
   // Middleware

dashcaddy-api/routes/health.js

@@ -6,6 +6,7 @@ const { TIMEOUTS } = require('../constants');
 const { exists } = require('../fs-helpers');
 const { paginate, parsePaginationParams } = require('../pagination');
 const platformPaths = require('../platform-paths');
+const { resolveServiceUrl } = require('../url-resolver');
 
 module.exports = function(ctx) {
   const router = express.Router();
@@ -36,18 +37,7 @@ module.exports = function(ctx) {
         let checkType = 'http';
 
         // Determine URL to check
-        if (service.isExternal && service.externalUrl) {
-          url = service.externalUrl;
-        } else if (service.containerId || service.containerName) {
-          // Local container - check via localhost and port
-          const port = service.port || 80;
-          url = `http://localhost:${port}`;
-        } else if (service.url) {
-          url = service.url.startsWith('http') ? service.url : `https://${service.url}`;
-        } else if (service.id) {
-          // Try common URL pattern
-          url = `https://${ctx.buildDomain(service.id)}`;
-        }
+        url = resolveServiceUrl(serviceId, service, ctx.siteConfig, ctx.buildServiceUrl);
 
         if (!url) {
           health[serviceId] = { status: 'unknown', reason: 'No URL configured' };
@@ -157,14 +147,7 @@ module.exports = function(ctx) {
     }
 
     // Determine URL
-    let url = null;
-    if (service.isExternal && service.externalUrl) {
-      url = service.externalUrl;
-    } else if (service.url) {
-      url = service.url.startsWith('http') ? service.url : `https://${service.url}`;
-    } else {
-      url = `https://${ctx.buildDomain(serviceId)}`;
-    }
+    const url = resolveServiceUrl(serviceId, service, ctx.siteConfig, ctx.buildServiceUrl);
 
     // Check health
     const controller = new AbortController();

dashcaddy-api/routes/logs.js

@@ -140,6 +140,7 @@ module.exports = function(ctx) {
 
   // Get latest daily digest
   router.get('/logs/digest/latest', ctx.asyncHandler(async (req, res) => {
+    if (!ctx.logDigest) return ctx.errorResponse(res, 503, 'Log digest not available');
     const digest = await ctx.logDigest.getLatestDigest();
     if (!digest) {
       return res.json({ success: true, digest: null, message: 'No digest available yet. First digest is generated at midnight.' });
@@ -149,18 +150,21 @@ module.exports = function(ctx) {
 
   // Get live digest data (today's accumulated stats)
   router.get('/logs/digest/live', ctx.asyncHandler(async (req, res) => {
+    if (!ctx.logDigest) return ctx.errorResponse(res, 503, 'Log digest not available');
     const live = ctx.logDigest.getLiveData();
     res.json({ success: true, ...live });
   }, 'logs-digest-live'));
 
   // List available digest dates
   router.get('/logs/digest/history', ctx.asyncHandler(async (req, res) => {
+    if (!ctx.logDigest) return ctx.errorResponse(res, 503, 'Log digest not available');
     const dates = await ctx.logDigest.listDigests();
     res.json({ success: true, dates });
   }, 'logs-digest-history'));
 
   // Generate digest on demand (for today or a specific date)
   router.post('/logs/digest/generate', ctx.asyncHandler(async (req, res) => {
+    if (!ctx.logDigest) return ctx.errorResponse(res, 503, 'Log digest not available');
     const date = req.body.date || new Date().toISOString().slice(0, 10);
     const digest = await ctx.logDigest.generateDailyDigest(date);
     res.json({ success: true, digest });
@@ -168,6 +172,7 @@ module.exports = function(ctx) {
 
   // Get digest for a specific date (JSON)
   router.get('/logs/digest/:date', ctx.asyncHandler(async (req, res) => {
+    if (!ctx.logDigest) return ctx.errorResponse(res, 503, 'Log digest not available');
     const { date } = req.params;
     if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) {
       return ctx.errorResponse(res, 400, 'Invalid date format. Use YYYY-MM-DD.');
@@ -186,6 +191,7 @@ module.exports = function(ctx) {
 
   // Get Docker disk usage snapshot
   router.get('/logs/docker-disk', ctx.asyncHandler(async (req, res) => {
+    if (!ctx.dockerMaintenance) return ctx.errorResponse(res, 503, 'Docker maintenance not available');
     const diskUsage = await ctx.dockerMaintenance.getDiskUsage();
     const status = ctx.dockerMaintenance.getStatus();
     res.json({ success: true, diskUsage, maintenance: status });
@@ -193,6 +199,7 @@ module.exports = function(ctx) {
 
   // Trigger Docker maintenance manually
   router.post('/logs/docker-maintenance', ctx.asyncHandler(async (req, res) => {
+    if (!ctx.dockerMaintenance) return ctx.errorResponse(res, 503, 'Docker maintenance not available');
     const result = await ctx.dockerMaintenance.runMaintenance();
     res.json({ success: true, result });
   }, 'logs-docker-maintenance'));

dashcaddy-api/routes/services.js

@@ -8,6 +8,7 @@ const { APP, REGEX, TIMEOUTS } = require('../constants');
 const { validateServiceConfig, isValidPort } = require('../input-validator');
 const { exists } = require('../fs-helpers');
 const { paginate, parsePaginationParams } = require('../pagination');
+const { resolveServiceUrl } = require('../url-resolver');
 
 module.exports = function(ctx) {
   const router = express.Router();
@@ -33,10 +34,7 @@ module.exports = function(ctx) {
   }
 
   function resolveProbeUrl(id, service) {
-    if (id === 'internet') return 'https://www.google.com';
-    if (service?.isExternal && service.externalUrl) return service.externalUrl;
-    if (service?.url) return service.url.startsWith('http') ? service.url : `https://${service.url}`;
-    return ctx.buildServiceUrl(id);
+    return resolveServiceUrl(id, service, ctx.siteConfig, ctx.buildServiceUrl);
   }
 
   function requestStatusCode(url, method) {
@@ -308,6 +306,7 @@ module.exports = function(ctx) {
         return services;
       });
 
+      ctx.resyncHealthChecker?.().catch(() => {});
       res.json({ success: true, message: `Service "${name}" added to dashboard` });
     } catch (error) {
       ctx.log.error('deploy', 'Error adding service', { error: error.message });
@@ -339,6 +338,7 @@ module.exports = function(ctx) {
     }
 
     await ctx.servicesStateManager.write(services);
+    ctx.resyncHealthChecker?.().catch(() => {});
 
     res.json({
       success: true,
@@ -367,6 +367,7 @@ module.exports = function(ctx) {
       return ctx.errorResponse(res, 404, `Service "${id}" not found`);
     }
 
+    ctx.resyncHealthChecker?.().catch(() => {});
     res.json({ success: true, message: `Service "${id}" removed from dashboard` });
   }, 'services-delete'));
 
@@ -454,6 +455,7 @@ module.exports = function(ctx) {
       });
     }
 
+    ctx.resyncHealthChecker?.().catch(() => {});
     res.json({
       success: true,
       message: `Service updated: ${oldSubdomain} -> ${newSubdomain}`,