Re-instate metadata request as fallback for CLSI

libraries/logger/logging-manager.js

@@ -1,4 +1,5 @@
 const bunyan = require('bunyan')
+const request = require('request')
 const fs = require('fs')
 const yn = require('yn')
 const OError = require('@overleaf/o-error')
@@ -41,7 +42,7 @@ const Logger = (module.exports = {
     return this
   },
 
-  checkLogLevel() {
+  checkLogLevelFile() {
     fs.readFile('/logging/tracingEndTime', (error, end) => {
       if (error || !end) {
         this.logger.level(this.defaultLevel)
@@ -55,6 +56,36 @@ const Logger = (module.exports = {
     })
   },
 
+  checkLogLevelMetadata() {
+    const options = {
+      headers: {
+        'Metadata-Flavor': 'Google'
+      },
+      uri: `http://metadata.google.internal/computeMetadata/v1/project/attributes/${this.loggerName}-setLogLevelEndTime`
+    }
+    request(options, (err, response, body) => {
+      if (err) {
+        this.logger.level(this.defaultLevel)
+        return
+      }
+      if (parseInt(body) > Date.now()) {
+        this.logger.level('trace')
+      } else {
+        this.logger.level(this.defaultLevel)
+      }
+    })
+  },
+
+  checkLogLevel() {
+    fs.access('/logging', (err) => {
+      if (err) {
+        this.checkLogLevelMetadata()
+      } else {
+        this.checkLogLevelFile()
+      }
+    })
+  },
+
   initializeErrorReporting(sentryDsn, options) {
     const raven = require('raven')
     this.raven = new raven.Client(sentryDsn, options)