add caching for manifests

index.js

@@ -46,14 +46,25 @@ app.use('/swagger.json', (req, res) => res.json(swaggerDocument))
 
 const urls = yaml.load(fs.readFileSync('./config/manifests/urls.yaml', 'utf8')).manifests
 
+let manifestCache = []
+let lastCached
+
+const getManifests = async () => {
+  if (+new Date() < lastCached + 30000) return
+  const results = urls.map(url => fetch(url).then(result => {
+    if (!result.ok) throw new Error(`Failed to load manifest for url ${result.url} (Status: ${result.status}: ${result.statusText})`)
+    return result.json().catch(err => { throw new Error(`Failed to load manifest for url ${result.url}: ${err}`) })
+  }))
+  manifestCache = (await Promise.all(results)).flat()
+  lastCached = +new Date()
+}
+
+getManifests()
+
 app.get('/api/manifest.json', async (req, res, next) => {
   try {
-    const results = urls.map(url => fetch(url).then(res => {
-      if (!res.ok) throw new Error(`Failed to load manifest for url ${res.url} (Status: ${res.status}: ${res.statusText})`)
-      return res.json().catch(err => { throw new Error(`Failed to load manifest for url ${res.url}: ${err}`) })
-    }))
-    const content = await Promise.all(results)
-    res.json(content.flat() || [])
+    getManifests()
+    res.json(manifestCache || [])
   } catch (err) {
     next(err)
   }

package.json

@@ -13,6 +13,7 @@
   "dependencies": {
     "@cloudnative/health-connect": "^2.1.0",
     "dotenv-defaults": "^2.0.1",
+    "eslint-config-standard": "^16.0.2",
     "express": "^4.17.1",
     "helmet": "^4.4.1",
     "js-yaml": "^4.0.0",
@@ -25,14 +26,12 @@
   },
   "devDependencies": {
     "eslint": "^7.20.0",
-    "eslint-config-standard": "^16.0.2",
     "eslint-plugin-import": "^2.22.1",
     "eslint-plugin-node": "^11.1.0",
-    "eslint-plugin-promise": "^4.3.1",
-    "eslint-plugin-standard": "^5.0.0",
+    "eslint-plugin-promise": "^5.1.0",
     "husky": ">=4",
     "lint-staged": ">=10",
-    "nodemon": "^1.19.4",
+    "nodemon": "^2.0.7",
     "pino-pretty": "^4.7.1"
   },
   "husky": {