const fetch = require('node-fetch') const fs = require('fs') class LogLevelChecker { constructor(logger, defaultLevel) { this.logger = logger this.defaultLevel = defaultLevel } start() { // check for log level override on startup this.checkLogLevel() // re-check log level every minute this.checkInterval = setInterval(this.checkLogLevel.bind(this), 1000 * 60) } stop() { clearInterval(this.checkInterval) } async checkLogLevel() { try { const end = await this.getTracingEndTime() if (end > Date.now()) { this.logger.level('trace') } else { this.logger.level(this.defaultLevel) } } catch (e) { this.logger.level(this.defaultLevel) } } async getTracingEndTime() { return 0 } } class FileLogLevelChecker extends LogLevelChecker { async getTracingEndTime() { const strEndTime = await fs.promises.readFile('/logging/tracingEndTime') return parseInt(strEndTime, 10) } } class GCEMetadataLogLevelChecker extends LogLevelChecker { async getTracingEndTime() { const options = { headers: { 'Metadata-Flavor': 'Google', }, } const uri = `http://metadata.google.internal/computeMetadata/v1/project/attributes/${this.logger.fields.name}-setLogLevelEndTime` const res = await fetch(uri, options) if (!res.ok) { throw new Error('Metadata not okay') } const strEndTime = await res.text() return parseInt(strEndTime, 10) } } module.exports = { FileLogLevelChecker, GCEMetadataLogLevelChecker }