AWS Lambda 和 Redis

Question

我正在尝试编写一个使用 redis（在 amazon elasticcache 上）的 AWS Lambda 函数。问题 – 我无法连接到 redis。我使用这样的代码

'use strict'

function handler (data, context, cb) {
  const redis = require("redis")
  console.log('before client initialization')
  const client = redis.createClient({
    url: 'redis://propper-url-cache.some.0001.euw1.cache.amazonaws.com:6379',
    retry_strategy: function(options) {
      console.log(options)
      if (options.total_retry_time > 1000) {
        throw new Error('can`t connect to redis')
      }
    }
  })
  console.log('after client initialization')

  client.on("error", function (err) {
    console.log('in error')
    cb({error: err})
  });

  client.get("counter", function (err, counter) {
    console.log('counter', counter)
    if(_.isNull(counter)) {
      counter = 0
    }
    client.set('counter', counter + 1, function(err) {
      console.log(err)
      cb(null, {counter: counter})
    })
  });
}

exports.handler = handler

结果我在日志中看到了这样的东西：

?
15:33:41
START RequestId: d8024ec2-7f36-11e6-996c-1bfcb60572c6 Version: $LATEST
?
15:33:42
2016-09-20T13:33:42.632Z    d8024ec2-7f36-11e6-996c-1bfcb60572c6    before client initialization
?
15:33:42
2016-09-20T13:33:42.813Z    d8024ec2-7f36-11e6-996c-1bfcb60572c6    after client initialization
?
15:33:44
END RequestId: d8024ec2-7f36-11e6-996c-1bfcb60572c6
?
15:33:44
REPORT RequestId: d8024ec2-7f36-11e6-996c-1bfcb60572c6  Duration: 3002.67 ms    Billed Duration: 3000 ms Memory Size: 128 MB    Max Memory Used: 19 MB
?
15:33:44
2016-09-20T13:33:44.620Z d8024ec2-7f36-11e6-996c-1bfcb60572c6 Task timed out after 3.00 seconds

当我为某些毫无意义的内容更改 redis url 时，我多了一行：

2016-09-20T13:29:42.953Z    48fcb071-7f36-11e6-bc52-c5ac58c12843    { attempt: 1, error: { [Error: Redis connection to some-url.euw1.cache.amazonaws.com:6379 failed - getaddrinfo ENOTFOUND some-url.euw1.cache.amazonaws.com some-url.euw1.cache.amazonaws.com:6379] code: 'ENOTFOUND', errno: 'ENOTFOUND', syscall: 'getaddrinfo', hostna

有任何想法吗？

Answer 1

您需要在与 Lambda 相同的 VPC 中安装 Redis。检查您的安全组设置。然后如果您有 EC2 访问权限，请安装 redis-cli 并尝试连接 Redis。如果此连接成功，您的 Lambda Redis 也将连接。如前所述，您需要将 lambda 放在同一个 VPC 中。以下是演示连接到 Lambda 的样板代码：

console.log('before client initialization')
const redisOptions = {
  host: 'xxxx.xxx.xxx.xxx.xxx.amazonaws.com',
  port: 6379,
}

var client =  redis.createClient(redisOptions);
console.log('after client initialization');

client.on('connect', function(result) {
  console.log('connected');
}