无法通过node.js从lambda获取Amazon日志

Question

我希望使用AWS.CloudWatchLogs.describeLogStreams获取cloudwatch日志，但返回的响应是httpstatuscode = 'undefined‘，而不是数据。

我该如何处理这个问题？

我执行以下代码来进行调试。

const aws = require('aws-sdk')

exports.handler = async (event, context) => {
  const cloudwatchlogs = new aws.CloudWatchLogs();
  const params = {
    logGroupName: '/aws/lambda/test'
  }
  var tmp = await cloudwatchlogs.describeLogStreams(params);
  console.log(tmp);
};

得到下面的日志。

2020-05-26T22:48:25.869Z    51891acf-302d-4d71-8f3b-b98cab65192d    INFO    Request {
  domain: null,
  service: Service {
    config: Config {
      credentials: [EnvironmentCredentials],
      credentialProvider: [CredentialProviderChain],
      region: 'ap-northeast-1',
      logger: null,
      apiVersions: {},
      apiVersion: null,
      endpoint: 'logs.ap-northeast-1.amazonaws.com',
      httpOptions: [Object],
      maxRetries: undefined,
      maxRedirects: 10,
      paramValidation: true,
      sslEnabled: true,
      s3ForcePathStyle: false,
      s3BucketEndpoint: false,
      s3DisableBodySigning: true,
      s3UsEast1RegionalEndpoint: 'legacy',
      s3UseArnRegion: undefined,
      computeChecksums: true,
      convertResponseTypes: true,
      correctClockSkew: false,
      customUserAgent: null,
      dynamoDbCrc32: true,
      systemClockOffset: 0,
      signatureVersion: 'v4',
      signatureCache: true,
      retryDelayOptions: {},
      useAccelerateEndpoint: false,
      clientSideMonitoring: false,
      endpointDiscoveryEnabled: false,
      endpointCacheSize: 1000,
      hostPrefixEnabled: true,
      stsRegionalEndpoints: 'legacy'
    },
    isGlobalEndpoint: false,
    endpoint: Endpoint {
      protocol: 'https:',
      host: 'logs.ap-northeast-1.amazonaws.com',
      port: 443,
      hostname: 'logs.ap-northeast-1.amazonaws.com',
      pathname: '/',
      path: '/',
      href: 'https://logs.ap-northeast-1.amazonaws.com/'
    },
    _events: { apiCallAttempt: [Array], apiCall: [Array] },
    MONITOR_EVENTS_BUBBLE: [Function: EVENTS_BUBBLE],
    CALL_EVENTS_BUBBLE: [Function: CALL_EVENTS_BUBBLE],
    _clientId: 1
  },
  operation: 'describeLogGroups',
  params: {},
  httpRequest: HttpRequest {
    method: 'POST',
    path: '/',
    headers: {
      'User-Agent': 'aws-sdk-nodejs/2.682.0 linux/v12.16.3 exec-env/AWS_Lambda_nodejs12.x'
    },
    body: '',
    endpoint: Endpoint {
      protocol: 'https:',
      host: 'logs.ap-northeast-1.amazonaws.com',
      port: 443,
      hostname: 'logs.ap-northeast-1.amazonaws.com',
      pathname: '/',
      path: '/',
      href: 'https://logs.ap-northeast-1.amazonaws.com/',
      constructor: [Function]
    },
    region: 'ap-northeast-1',
    _userAgent: 'aws-sdk-nodejs/2.682.0 linux/v12.16.3 exec-env/AWS_Lambda_nodejs12.x'
  },
  startTime: 2020-05-26T22:48:25.866Z,
  response: Response {
    request: [Circular],
    data: null,
    error: null,
    retryCount: 0,
    redirectCount: 0,
    httpResponse: HttpResponse {
      statusCode: undefined,
      headers: {},
      body: undefined,
      streaming: false,
      stream: null
    },
    maxRetries: 3,
    maxRedirects: 10
  },
  _asm: AcceptorStateMachine {
    currentState: 'validate',
    states: {
      validate: [Object],
      build: [Object],
      afterBuild: [Object],
      sign: [Object],
      retry: [Object],
      afterRetry: [Object],
      send: [Object],
      validateResponse: [Object],
      extractError: [Object],
      extractData: [Object],
      restart: [Object],
      success: [Object],
      error: [Object],
      complete: [Object]
    }
  },
  _haltHandlersOnError: false,
  _events: {
    validate: [
      [Function],
      [Function],
      [Function: VALIDATE_REGION],
      [Function: BUILD_IDEMPOTENCY_TOKENS],
      [Function: VALIDATE_PARAMETERS]
    ],
    afterBuild: [
      [Function],
      [Function: SET_CONTENT_LENGTH],
      [Function: SET_HTTP_HOST]
    ],
    restart: [ [Function: RESTART] ],
    sign: [ [Function], [Function], [Function] ],
    validateResponse: [ [Function: VALIDATE_RESPONSE], [Function] ],
    send: [ [Function] ],
    httpHeaders: [ [Function: HTTP_HEADERS] ],
    httpData: [ [Function: HTTP_DATA] ],
    httpDone: [ [Function: HTTP_DONE] ],
    retry: [
      [Function: FINALIZE_ERROR],
      [Function: INVALIDATE_CREDENTIALS],
      [Function: EXPIRED_SIGNATURE],
      [Function: CLOCK_SKEWED],
      [Function: REDIRECT],
      [Function: RETRY_CHECK],
      [Function: API_CALL_ATTEMPT_RETRY]
    ],
    afterRetry: [ [Function] ],
    build: [ [Function: buildRequest] ],
    extractData: [ [Function: extractData], [Function: extractRequestId] ],
    extractError: [ [Function: extractError], [Function: extractRequestId] ],
    httpError: [ [Function: ENOTFOUND_ERROR] ],
    success: [ [Function: API_CALL_ATTEMPT] ],
    complete: [ [Function: API_CALL] ]
  },
  emit: [Function: emit],
  API_CALL_ATTEMPT: [Function: API_CALL_ATTEMPT],
  API_CALL_ATTEMPT_RETRY: [Function: API_CALL_ATTEMPT_RETRY],
  API_CALL: [Function: API_CALL]
}

补编：

• 我的lambda函数有CloudWatchFullAccess策略
• 我可以在cloudwatch控制台中看到此函数的cloudwatch日志。
• 我的lambda函数运行库是Node.js 12.x

Answer 1

我认为这是因为你的函数在得到任何结果之前就完成了。克服这一问题的一种方法是为异步处理程序使用模式，如aws博士所示。

const aws = require('aws-sdk')

exports.handler = async (event, context) => {
  const promise = new Promise(function(resolve, reject) {
    const cloudwatchlogs = new aws.CloudWatchLogs();
    const params = {
      logGroupName: '/aws/lambda/test'
    }
    cloudwatchlogs.describeLogStreams(params, function(err, data) {
      if (err) console.log(err, err.stack); // an error occurred
      else     console.log(data);           // successful response
    });
  })
  return promise;

};

上面的代码工作。我用我自己的lambda函数测试了它。