Lambdaのブループリントのうちdatadog-process-rds-metricsを利用して、Lambda関数を作成してみます。

今回は、KMSを使わないこととします。

前提条件

Lambdaへの権限

Lambdaに対してフル権限があること。

AWS CLI

以下のバージョンで動作確認済

AWS CLI 1.11.28

コマンド

aws --version

結果(例):

  aws-cli/1.11.28 Python/2.7.10 Darwin/15.6.0 botocore/1.4.85

バージョンが古い場合は最新版に更新しましょう。

コマンド

sudo -H pip install -U awscli

IAM Role

'lambdaBasicExecution'ロールが存在すること。

変数の設定

IAM_ROLE_NAME='lambdaBasicExecution'

コマンド

aws iam get-role \
         --role-name ${IAM_ROLE_NAME}

結果(例):

  {
      "Role": {
        "AssumeRolePolicyDocument": {
            "Version": "2012-10-17",
            "Statement": [
                {
                    "Action": "sts:AssumeRole",
                    "Principal": {
                        "Service": "lambda.amazonaws.com"
                    },
                    "Effect": "Allow",
                    "Sid": ""
                }
            ]
        },
        "RoleId": "AROAXXXXXXXXXXXXXXXXX",
        "CreateDate": "2016-12-18T01:23:45Z",
        "RoleName": "lambdaBasicExecution",
        "Path": "/",
        "Arn": "arn:aws:iam::XXXXXXXXXXXX:role/lambdaBasicExecution"
      }
  }

IAMロールが存在しない場合、
http://qiita.com/tcsh/items/6353876a5c4fef63b4d8 の手順に従って作成し
てください。

準備
=======

0.1. リージョンの決定

変数の設定

export AWS_DEFAULT_REGION='ap-northeast-1'

0.2. 変数の確認

プロファイルが想定のものになっていることを確認します。

変数の確認

aws configure list

結果(例):

        Name                    Value             Type    Location
        ----                    -----             ----    --------
     profile       lambdaFull-prjz-mbp13        env    AWS_DEFAULT_PROFILE
  access_key     ****************XXXX shared-credentials-file
  secret_key     ****************XXXX shared-credentials-file
      region        ap-northeast-1        env    AWS_DEFAULT_REGION

事前作業
===========

1.1. IAM RoleのARN取得

コマンド

IAM_ROLE_ARN=$( \
        aws iam get-role \
          --role-name ${IAM_ROLE_NAME} \
          --query 'Role.Arn' \
          --output text \
) \
        && echo ${IAM_ROLE_ARN}

結果(例):

  arn:aws:iam::XXXXXXXXXXXX:role/lambdaBasicExecution

1.2. DatadogのAPIキーの設定

https://app.datadoghq.com/account/settings#api にアクセスします。

変数の設定

DD_API_KEY='<API KeysのKeyの値>'

New application keyに'lambda'と入力し、Create Application Keyボタンをクリックします。

Hashの値を変数に取り込みます。

変数の設定

DD_APP_KEY='<Application KeyのHashの値>'

1.3. Lambda関数名の決定

変数の設定

LAMBDA_FUNC_NAME="datadog_process_rds_metrics-$( date '+%Y%m%d' )" \
        && echo ${LAMBDA_FUNC_NAME}

同名のLambda関数の不存在確認

コマンド

aws lambda get-function \
        --function-name ${LAMBDA_FUNC_NAME}

結果(例):

  A client error (ResourceNotFoundException) occurred when calling the GetFunction operation: Function not found: arn:aws:lambda:ap-northeast-1:XXXXXXXXXXXX:function:datadog_process_rds_metrics-20161219

1.4. Lambda関数

変数の設定

FILE_LAMBDA_FUNC="${LAMBDA_FUNC_NAME}.py"
PY_FUNC_NAME='lambda_handler'

変数の確認

cat << ETX

          FILE_LAMBDA_FUNC: ${FILE_LAMBDA_FUNC}
          PY_FUNC_NAME:     ${PY_FUNC_NAME}
          DD_API_KEY:       ${DD_API_KEY}
          DD_APP_KEY:       ${DD_APP_KEY}

ETX

コマンド

cat << EOF > ${FILE_LAMBDA_FUNC}
from __future__ import print_function

import os
import gzip
import json
import re
import time
import urllib
import urllib2
from base64 import b64decode
from StringIO import StringIO

import boto3

# retrieve datadog options from KMS
#KMS_ENCRYPTED_KEYS = os.environ['kmsEncryptedKeys']
#kms = boto3.client('kms')
datadog_keys = json.loads('{"api_key":"${DD_API_KEY}", "app_key":"${DD_APP_KEY}"}')

print('INFO Lambda function initialized, ready to send metrics')


def _process_rds_enhanced_monitoring_message(ts, message, account, region):
    instance_id = message['instanceID']
    host_id = message['instanceResourceID']
    tags = [
        'dbinstanceidentifier:%s' % instance_id,
        'aws_account:%s' % account,
        'engine:%s' % message["engine"],
    ]

    # metrics generation

    uptime = 0
    uptime_msg = re.split(' days?, ', message['uptime'])
    if len(uptime_msg) == 2:
        uptime += 24 * 3600 * int(uptime_msg[0])
    uptime_day = uptime_msg[-1].split(':')
    uptime += 3600 * int(uptime_day[0])
    uptime += 60 * int(uptime_day[1])
    uptime += int(uptime_day[2])
    stats.gauge('aws.rds.uptime', uptime, timestamp=ts, tags=tags, host=host_id)

    stats.gauge('aws.rds.virtual_cpus', message['numVCPUs'], timestamp=ts, tags=tags, host=host_id)

    stats.gauge('aws.rds.load.1', message['loadAverageMinute']['one'], timestamp=ts, tags=tags, host=host_id)
    stats.gauge('aws.rds.load.5', message['loadAverageMinute']['five'], timestamp=ts, tags=tags, host=host_id)
    stats.gauge('aws.rds.load.15', message['loadAverageMinute']['fifteen'], timestamp=ts, tags=tags, host=host_id)

    for namespace in ['cpuUtilization', 'memory', 'tasks', 'swap']:
        for key, value in message[namespace].iteritems():
            stats.gauge('aws.rds.%s.%s' % (namespace.lower(), key), value, timestamp=ts, tags=tags, host=host_id)

    for network_stats in message['network']:
        network_tag = ['interface:%s' % network_stats.pop('interface')]
        for key, value in network_stats.iteritems():
            stats.gauge('aws.rds.network.%s' % key, value, timestamp=ts, tags=tags + network_tag, host=host_id)

    disk_stats = message['diskIO'][0]  # we never expect to have more than one disk
    for key, value in disk_stats.iteritems():
        stats.gauge('aws.rds.diskio.%s' % key, value, timestamp=ts, tags=tags, host=host_id)

    for fs_stats in message['fileSys']:
        fs_tag = [
            'name:%s' % fs_stats.pop('name'),
            'mountPoint:%s' % fs_stats.pop('mountPoint')
        ]
        for key, value in fs_stats.iteritems():
            stats.gauge('aws.rds.filesystem.%s' % key, value, timestamp=ts, tags=tags + fs_tag, host=host_id)

    for process_stats in message['processList']:
        process_tag = [
            'name:%s' % process_stats.pop('name'),
            'id:%s' % process_stats.pop('id')
        ]
        for key, value in process_stats.iteritems():
            stats.gauge('aws.rds.process.%s' % key, value, timestamp=ts, tags=tags + process_tag, host=host_id)


def ${PY_FUNC_NAME}(event, context):
    ''' Process a RDS enhenced monitoring DATA_MESSAGE,
        coming from CLOUDWATCH LOGS
    '''
    # event is a dict containing a base64 string gzipped
    event = json.loads(gzip.GzipFile(fileobj=StringIO(event['awslogs']['data'].decode('base64'))).read())

    account = event['owner']
    region = context.invoked_function_arn.split(':', 4)[3]

    log_events = event['logEvents']

    for log_event in log_events:
        message = json.loads(log_event['message'])
        ts = log_event['timestamp'] / 1000
        _process_rds_enhanced_monitoring_message(ts, message, account, region)

    stats.flush()
    return {'Status': 'OK'}


# Helpers to send data to Datadog, inspired from https://github.com/DataDog/datadogpy

class Stats(object):

    def __init__(self):
        self.series = []

    def gauge(self, metric, value, timestamp=None, tags=None, host=None):
        base_dict = {
            'metric': metric,
            'points': [(int(timestamp or time.time()), value)],
            'type': 'gauge',
            'tags': tags,
        }
        if host:
            base_dict.update({'host': host})
        self.series.append(base_dict)

    def flush(self):
        metrics_dict = {
            'series': self.series,
        }
        self.series = []

        creds = urllib.urlencode(datadog_keys)
        data = json.dumps(metrics_dict)
        url = '%s?%s' % (datadog_keys.get('api_host', 'https://app.datadoghq.com/api/v1/series'), creds)
        req = urllib2.Request(url, data, {'Content-Type': 'application/json'})
        response = urllib2.urlopen(req)
        print('INFO Submitted data with status {}'.format(response.getcode()))

stats = Stats()
EOF

cat ${FILE_LAMBDA_FUNC}

コマンド

zip ${LAMBDA_FUNC_NAME}.zip ${FILE_LAMBDA_FUNC}

結果(例):

  adding: datadog_process_rds_metrics-20161219.py (deflated 43%)

Lambda関数の作成
===================

2.1. Lambda関数の作成

変数の設定

LAMBDA_FUNC_DESC='Pushes RDS Enhanced metrics to Datadog.'
LAMBDA_RUNTIME='python2.7'
LAMBDA_HANDLER="${LAMBDA_FUNC_NAME}.${PY_FUNC_NAME}"
FILE_LAMBDA_ZIP="${LAMBDA_FUNC_NAME}.zip"

変数の確認

cat << ETX

        LAMBDA_FUNC_NAME:  ${LAMBDA_FUNC_NAME}
        LAMBDA_FUNC_DESC: "${LAMBDA_FUNC_DESC}"
        LAMBDA_RUNTIME:    ${LAMBDA_RUNTIME}
        FILE_LAMBDA_ZIP    ${FILE_LAMBDA_ZIP}
        IAM_ROLE_ARN:      ${IAM_ROLE_ARN}
        LAMBDA_HANDLER:    ${LAMBDA_HANDLER}

ETX

コマンド

aws lambda create-function \
        --function-name ${LAMBDA_FUNC_NAME} \
        --description "${LAMBDA_FUNC_DESC}" \
        --zip-file fileb://${FILE_LAMBDA_ZIP} \
        --runtime ${LAMBDA_RUNTIME} \
        --role ${IAM_ROLE_ARN} \
        --handler ${LAMBDA_HANDLER}

結果(例):

  {
    "CodeSha256": "lKbgNPMuV0D2blwwCSWwKLwlTrzoPAsFAdB6/FxJ+Q4=",
    "FunctionName": "datadog_process_rds_metrics-20161219",
    "CodeSize": 1962,
    "MemorySize": 128,
    "FunctionArn": "arn:aws:lambda:ap-northeast-1:XXXXXXXXXXXX:function:datadog_process_rds_metrics-20161219",
    "Version": "$LATEST",
    "Role": "arn:aws:iam::XXXXXXXXXXXX:role/lambdaBasicExecution",
    "Timeout": 3,
    "LastModified": "2016-12-18T01:23:45.678+0000",
    "Handler": "datadog_process_rds_metrics-20161219.lambda_handler",
    "Runtime": "python2.7",
    "Description": "Pushes RDS Enhanced metrics to Datadog."
  }

コマンド

aws lambda get-function \
        --function-name ${LAMBDA_FUNC_NAME}

結果(例):

  {
    "Code": {
      "RepositoryType": "S3",
      "Location": "https://awslambda-ap-ne-1-tasks.s3-ap-northeast-1.amazonaws.com/snapshots/XXXXXXXXXXXX/HelloWorld-2979ba79-b08f-495d-9ee6-46397c95ba13?x-amz-security-token=AQoDYXdzEDoa8AMR6t8h66eOXhN3%2Fx7XpuRxvf7pVn7IuWV4cEmwx0CtZT6yxCJ1%2BWmigYXqGoyQHuBYOWnxbhmwEcTg839qMuhSu1fk0fXpXf0oJOLkhKMudNqhdElyFQpzyT6Q8GDfhAsfbX9wvwCDTty4imxz7MczF%2FQl6tgvTYdip08ap5fAyrknZGV1%2B1Ggnp5w6JOjydYxuUsWwhoxoEWzi7SoVTmpRQQA91c4VW9lNotOAHACFxo6klzDPM8mxR9RJl66WxFugL0wQJyLUpmtjS9XoArD86sEWWiIccMpV2BQipTPQlzL%2F1Hoy%2BDF6QUxyPUihlDjPBoJTISTP8W1wxmzW%2BLbilAfFQRPY7CFjzR0k%2FA%2FIX5x9iyz52Pu1Q0ASTw1l%2Fq%2Fo3pRbvzWR79QS%2BpxXrwbYzoQHKiK62DSTsQo5tqKPsiDCYzrPxbq8lm7pNBPG%2FsxjePRWBVJeRl08WxEjSjoRRwBOPX5mz1BCUoUBPGG5tEENp87A%2FCdDgibFWM5DdYhwtaYPY7FTmi8DvqjQHL9jOmP8YuVteBTBcv8nFW6UbErPjwwn79FKG1u5M9HoTWUqUMBByz6D4tTRSEw6iJU7XdCujFnhnHe5V8imZ1KGI7fDWpciJhrhml0wnKPCK%2Fe9lK1P2kO7ldSWc7zn5hcIOD2tbEF&AWSAccessKeyId=ASIAJFVALOKV5SJVYPPA&Expires=1445825978&Signature=bvwu1Ny34LgTmZeOO3q4sn7x3Fg%3D"
    },
    "Configuration": {
      "Version": "$LATEST",
      "CodeSha256": "lKbgNPMuV0D2blwwCSWwKLwlTrzoPAsFAdB6/FxJ+Q4=",
      "FunctionName": "datadog_process_rds_metrics-20161219",
      "MemorySize": 128,
      "CodeSize": 350,
      "FunctionArn": "arn:aws:lambda:ap-northeast-1:XXXXXXXXXXXX:function:datadog_process_rds_metrics-20161219",
      "Handler": "datadog_process_rds_metrics-20161219.lambda_handler",
      "Role": "arn:aws:iam::XXXXXXXXXXXX:role/lambdaBasicExecution",
      "Timeout": 3,
      "LastModified": "2016-12-18T01:23:45.678+0000",
      "Runtime": "python2.7",
      "Description": "Pushes RDS Enhanced metrics to Datadog."
    }
  }

2.2. Lambda関数の更新

デフォルトの3秒ではタイムアウトする可能性が高いので、ここでは30秒に変更します。

変数の設定

LAMBDA_TIMEOUT='30'

変数の確認

cat << ETX

        LAMBDA_FUNC_NAME: ${LAMBDA_FUNC_NAME}
        LAMBDA_TIMEOUT:   ${LAMBDA_TIMEOUT}

ETX

コマンド

aws lambda update-function-configuration \
        --function-name ${LAMBDA_FUNC_NAME} \
        --timeout "${LAMBDA_TIMEOUT}"

結果(例):

  {
    "CodeSha256": "lKbgNPMuV0D2blwwCSWwKLwlTrzoPAsFAdB6/FxJ+Q4=",
    "FunctionName": "datadog_process_rds_metrics-20161219",
    "VpcConfig": {
        "SubnetIds": [],
        "SecurityGroupIds": []
    },
    "CodeSize": 350,
    "MemorySize": 128,
    "FunctionArn": "arn:aws:lambda:ap-northeast-1:XXXXXXXXXXXX:function:datadog_process_rds_metrics-20161219",
    "Version": "$LATEST",
    "Role": "arn:aws:iam::XXXXXXXXXXXX:role/lambdaBasicExecution",
    "Timeout": 30,
    "LastModified": "2016-12-18T01:23:45.678+0000",
    "Handler": "datadog_process_rds_metrics-20161219.handler",
    "Runtime": "python2.7",
    "Description": "Pushes RDS Enhanced metrics to Datadog."
  }

Lambda関数の動作確認
=======================

3.1. サンプルデータの作成

変数の設定

FILE_INPUT="${LAMBDA_FUNC_NAME}-log-data.json" \
          && echo ${FILE_INPUT}

サンプルデータ

cat << EOF > ${FILE_INPUT}
{
        "messageType":"DATA_MESSAGE",
        "owner":"123456789123",
        "logGroup":"testLogGroup",
        "logStream":"testLogStream",
        "subscriptionFilters":[
          "testFilter"
        ],
        "logEvents":[
          {
            "id":"eventId1",
            "timestamp":1440442987000,
            "message": "{\"engine\":\"Postgres\",\"instanceID\":\"postgresql-redmine-20161211\",\"instanceResourceID\":\"db-7ZOMGTEKHCZNLIFRXB3TOTR2XQ\",\"timestamp\":\"2016-12-13T06:11:44Z\",\"version\":1.00,\"uptime\":\"2 days, 0:40:25\",\"numVCPUs\":1,\"cpuUtilization\":{\"guest\":0.00,\"irq\":0.00,\"system\":0.27,\"wait\":0.20,\"idle\":98.80,\"user\":0.67,\"total\":1.21,\"steal\":0.00,\"nice\":0.07},\"loadAverageMinute\":{\"fifteen\":0.05,\"five\":0.01,\"one\":0.00},\"memory\":{\"writeback\":12,\"hugePagesFree\":0,\"hugePagesRsvd\":0,\"hugePagesSurp\":0,\"cached\":591812,\"hugePagesSize\":2048,\"free\":103168,\"hugePagesTotal\":0,\"inactive\":388232,\"pageTables\":4740,\"dirty\":164,\"mapped\":33312,\"active\":428844,\"total\":1020188,\"slab\":44440,\"buffers\":56164},\"tasks\":{\"sleeping\":146,\"zombie\":0,\"running\":4,\"stopped\":0,\"total\":150,\"blocked\":0},\"swap\":{\"cached\":0,\"total\":4095996,\"free\":4095928},\"network\":[{\"interface\":\"eth0\",\"rx\":451.53,\"tx\":3785.40}],\"diskIO\":[{\"writeKbPS\":16.80,\"readIOsPS\":0.00,\"await\":3.87,\"readKbPS\":0.00,\"rrqmPS\":0.00,\"util\":0.08,\"avgQueueLen\":0.24,\"tps\":4.20,\"readKb\":0,\"device\":\"rdsdev\",\"writeKb\":252,\"avgReqSz\":4.00,\"wrqmPS\":0.00,\"writeIOsPS\":4.20}],\"fileSys\":[{\"used\":625804,\"name\":\"rdsfilesys\",\"usedFiles\":1910,\"usedFilePercent\":0.58,\"maxFiles\":327040,\"mountPoint\":\"/rdsdbdata\",\"total\":5017092,\"usedPercent\":12.47}],\"processList\":[{\"vss\":407876,\"name\":\"postgres: pgadmin redmine 172.18.16.8(35898) idle\",\"tgid\":3097,\"parentID\":3320,\"memoryUsedPc\":1.44,\"cpuUsedPc\":0.00,\"id\":3097,\"rss\":14740},{\"vss\":68748,\"name\":\"postgres: logger process   \",\"tgid\":3321,\"parentID\":3320,\"memoryUsedPc\":0.16,\"cpuUsedPc\":0.00,\"id\":3321,\"rss\":1660},{\"vss\":289936,\"name\":\"postgres: checkpointer process   \",\"tgid\":3323,\"parentID\":3320,\"memoryUsedPc\":1.43,\"cpuUsedPc\":0.00,\"id\":3323,\"rss\":14636},{\"vss\":289936,\"name\":\"postgres: writer process   \",\"tgid\":3324,\"parentID\":3320,\"memoryUsedPc\":0.51,\"cpuUsedPc\":0.00,\"id\":3324,\"rss\":5216},{\"vss\":289936,\"name\":\"postgres: wal writer process   \",\"tgid\":3325,\"parentID\":3320,\"memoryUsedPc\":0.79,\"cpuUsedPc\":0.00,\"id\":3325,\"rss\":8100},{\"vss\":289936,\"name\":\"postgres: autovacuum launcher process   \",\"tgid\":3326,\"parentID\":3320,\"memoryUsedPc\":0.27,\"cpuUsedPc\":0.00,\"id\":3326,\"rss\":2784},{\"vss\":68744,\"name\":\"postgres: archiver process   last was 00000001000000020000002B\",\"tgid\":3327,\"parentID\":3320,\"memoryUsedPc\":0.16,\"cpuUsedPc\":0.00,\"id\":3327,\"rss\":1672},{\"vss\":68744,\"name\":\"postgres: stats collector process   \",\"tgid\":3328,\"parentID\":3320,\"memoryUsedPc\":0.19,\"cpuUsedPc\":0.00,\"id\":3328,\"rss\":1968},{\"vss\":399712,\"name\":\"postgres: pgadmin redmine 172.18.16.8(36634) idle\",\"tgid\":6552,\"parentID\":3320,\"memoryUsedPc\":0.89,\"cpuUsedPc\":0.00,\"id\":6552,\"rss\":9128},{\"vss\":393516,\"name\":\"postgres: rdsadmin rdsadmin localhost(63217) idle\",\"tgid\":27304,\"parentID\":3320,\"memoryUsedPc\":0.77,\"cpuUsedPc\":0.00,\"id\":27304,\"rss\":7832},{\"vss\":289936,\"name\":\"postgres\",\"tgid\":3320,\"parentID\":1,\"memoryUsedPc\":1.78,\"cpuUsedPc\":0.00,\"id\":3320,\"rss\":18140},{\"vss\":657332,\"name\":\"OS processes\",\"tgid\":0,\"parentID\":0,\"memoryUsedPc\":2.22,\"cpuUsedPc\":0.00,\"id\":0,\"rss\":22472},{\"vss\":887200,\"name\":\"RDS processes\",\"tgid\":0,\"parentID\":0,\"memoryUsedPc\":15.71,\"cpuUsedPc\":0.07,\"id\":0,\"rss\":160176}]}"
          }
        ]
}
EOF

cat ${FILE_INPUT}

JSONファイルを作成したら、フォーマットが壊れてないか必ず確認します。

コマンド

jsonlint -q ${FILE_INPUT}

エラーが出力されなければOKです。

コマンド

gzip ${FILE_INPUT}

コマンド

STR_DATA=$( cat ${FILE_INPUT}.gz | base64 ) \
        && echo ${STR_DATA}

変数の設定

FILE_INPUT="${LAMBDA_FUNC_NAME}-data.json" \
          && echo ${FILE_INPUT}

サンプルデータ

cat << EOF > ${FILE_INPUT}
{
        "awslogs": {
          "data": "${STR_DATA}"
        }
}
EOF

cat ${FILE_INPUT}

JSONファイルを作成したら、フォーマットが壊れてないか必ず確認します。

コマンド

jsonlint -q ${FILE_INPUT}

エラーが出力されなければOKです。

3.2. lambda関数の手動実行

変数の設定

FILE_OUTPUT_LAMBDA="${LAMBDA_FUNC_NAME}-out.txt"
FILE_LOG_LAMBDA="${LAMBDA_FUNC_NAME}-$(date +%Y%m%d%H%M%S).log"

変数の確認

cat << ETX

        LAMBDA_FUNC_NAME:   ${LAMBDA_FUNC_NAME}
        FILE_INPUT:         ${FILE_INPUT}
        FILE_OUTPUT_LAMBDA: ${FILE_OUTPUT_LAMBDA}
        FILE_LOG_LAMBDA:    ${FILE_LOG_LAMBDA}

ETX

コマンド

aws lambda invoke \
        --function-name ${LAMBDA_FUNC_NAME} \
        --log-type Tail \
        --payload file://${FILE_INPUT} \
        ${FILE_OUTPUT_LAMBDA} \
        > ${FILE_LOG_LAMBDA}

コマンド

cat ${FILE_LOG_LAMBDA} \
        | jp.py 'StatusCode'

結果(例):

3.3. lambda関数の実行結果の確認

コマンド

cat ${FILE_OUTPUT_LAMBDA}

結果(例):

  {"Status": "OK"}

3.4. lambda関数のログの確認

コマンド

cat ${FILE_LOG_LAMBDA} \
        | jp.py 'LogResult' \
        | sed 's/"//g' \
        | base64 --decode

結果(例):

  START RequestId: 4620fd3f-c0fb-11e6-be7f-5d539d6c06cd Version: $LATEST
  INFO Submitted data with status 202
  END RequestId: 4620fd3f-c0fb-11e6-be7f-5d539d6c06cd
  REPORT RequestId: 4620fd3f-c0fb-11e6-be7f-5d539d6c06cd      Duration: 1019.04 ms    Billed Duration: 1100 ms        Memory Size: 128 MB     Max Memory Used: 31 MB

完了