ラムダでエラーが発生した場合、CloudWatchLogsを検索してSNSに通知する。(要AWS SDK for Ruby V3)

Gemfile

# frozen_string_literal: true

source "https://rubygems.org"

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

# gem "rails"
gem 'aws-sdk', '~> 3'
gem "activesupport"

lambda_send_sns.rb

# -*- coding: utf-8 -*-
# frozen_string_literal: true
#
# https://qiita.com/onooooo/items/f59c69e30dc5b477f9fd よりRubyに移植し、全CloudWatchLogsからロググループを探索するように修正。
#
require 'aws-sdk'
require 'json'
require 'time'
require 'active_support/core_ext'

# SNSトピックのARN
TOPIC_ARN = 'arn:aws:sns:ap-northeast-1:0123456789:SendEmail_Lambda_Alert_TOPIC_NAME'

# 抽出するログデータの最大件数
OUTPUT_LIMIT = 5
# 何分前までを抽出対象期間とするか
TIME_FROM_MIN = 10

def lambda_handler(event, context)
  print event
  message = event['Records'][0]['Sns']['Message']
  print 'SNS Message:' + message
  message = JSON.parse(message)
  message['AlarmDescription'] ||= ''

  print message
  print 'step1'

  begin
    logs = Aws::CloudWatchLogs::Client.new(
      region: 'ap-northeast-1'
    )
    print message['Trigger']['MetricName']
    print message['Trigger']['NameSpace']
    logs.describe_log_groups({
      log_group_name_prefix: '/aws/lambda/'
    }).each_page do |resp|
      log_groups = resp['logGroups']
      print log_groups
      log_groups.each do |log_group|
        print 'step2'
        # "StateChangeTime": "2019-10-02T03:06:09.551+0000"
        timeto = Time.strptime(message['StateChangeTime'][0, 19], '%Y-%m-%dT%H:%M:%S').since(1.minute)
        u_to = timeto.to_i * 1000
        timefrom = timeto.ago(TIME_FROM_MIN.minutes)
        u_from = timefrom.to_i * 1000
        print 'step3'
        logs.filter_log_events({
          logGroupName: log_group['logGroupName'] ,
          filterPattern: 'Error',
          startTime: u_from,
          endTime: u_to,
          limit: OUTPUT_LIMIT
        }).each_page do |log_event|
          print log_event
          log_message = ''
          log_event['events'].each do |e|
            date = Time.at(e['timestamp'][10]).since(9.hour)
            log_message = log_message + '\n' + str(date) + ' : ' + e['message']
          end
          title = 'ラムダでエラー発生：' + log_group['logGroupName']
          sns_message = message['AlarmDescription'] + '\n' + log_message
          print sns_message
          sns = Aws::Sns::Client.new(
            region: 'ap-northeast-1'
          )
          sns.publish({
            TopicArn: TOPIC_ARN,
            Message: sns_message,
            Subject: title
          })
        end
      end
    end
  rescue
    puts '何か問題が発生しました。'
  end


end