Merge pull request #11733 from overleaf/msm-close-site-sp-shutdwn

[CE/SP] close site on shutdown before flushing

GitOrigin-RevId: e36c80f2f4c6f10eda3a536319a2fcc5dfda4fa4

services/web/app.js

@@ -14,6 +14,7 @@ metrics.initialize(process.env.METRICS_APP_NAME || 'web')
 const Settings = require('@overleaf/settings')
 const logger = require('@overleaf/logger')
 const PlansLocator = require('./app/src/Features/Subscription/PlansLocator')
+const SiteAdminHandler = require('./app/src/infrastructure/SiteAdminHandler')
 logger.initialize(process.env.METRICS_APP_NAME || 'web')
 logger.logger.serializers.user =
   require('./app/src/infrastructure/LoggerSerializers').user
@@ -78,6 +79,9 @@ if (!module.parent) {
     })
 }
 
+// monitor site maintenance file
+SiteAdminHandler.initialise()
+
 // handle SIGTERM for graceful shutdown in kubernetes
 process.on('SIGTERM', function (signal) {
   triggerGracefulShutdown(Server.server, signal)

services/web/app/src/infrastructure/SiteAdminHandler.js

@@ -0,0 +1,65 @@
+const logger = require('@overleaf/logger')
+const settings = require('@overleaf/settings')
+const fs = require('fs')
+const {
+  addOptionalCleanupHandlerAfterDrainingConnections,
+} = require('./GracefulShutdown')
+
+// Monitor a site maintenance file (e.g. /etc/site_status) periodically and
+// close the site if the file contents contain the string "closed".
+
+const STATUS_FILE_CHECK_INTERVAL = 5000
+const statusFile = settings.siteMaintenanceFile
+
+function updateSiteMaintenanceStatus(fileContent) {
+  const isClosed = !settings.siteIsOpen
+  const shouldBeClosed = fileContent && fileContent.indexOf('closed') >= 0
+  if (!isClosed && shouldBeClosed) {
+    settings.siteIsOpen = false
+    logger.warn({ fileContent }, 'putting site into maintenance mode')
+  } else if (isClosed && !shouldBeClosed) {
+    settings.siteIsOpen = true
+    logger.warn({ fileContent }, 'taking site out of maintenance mode')
+  }
+}
+
+function pollSiteMaintenanceFile() {
+  fs.readFile(statusFile, { encoding: 'utf8' }, (err, fileContent) => {
+    if (err) {
+      logger.error(
+        { file: statusFile, fsErr: err },
+        'error reading site maintenance file'
+      )
+      return
+    }
+    updateSiteMaintenanceStatus(fileContent)
+  })
+}
+
+function checkSiteMaintenanceFileSync() {
+  // crash on start up if file does not exist
+  const content = fs.readFileSync(statusFile, { encoding: 'utf8' })
+  updateSiteMaintenanceStatus(content)
+}
+
+module.exports = {
+  initialise() {
+    if (settings.enabledServices.includes('web') && statusFile) {
+      logger.debug(
+        { statusFile, interval: STATUS_FILE_CHECK_INTERVAL },
+        'monitoring site maintenance file'
+      )
+      checkSiteMaintenanceFileSync() // perform an initial synchronous check at start up
+      const intervalHandle = setInterval(
+        pollSiteMaintenanceFile,
+        STATUS_FILE_CHECK_INTERVAL
+      ) // continue checking periodically
+      addOptionalCleanupHandlerAfterDrainingConnections(
+        'poll site maintenance file',
+        () => {
+          clearInterval(intervalHandle)
+        }
+      )
+    }
+  },
+}