RDSを利用したECSサーバ基盤の構築

前述、SLBを利用したECSサーバ基盤の構築が出来たら、今度はこれにRDSをアタッチしてみます。

構成図

  TerraformでデータベースサービスであるRDSを作ってみます。ゴールの構成図は以下の通りです。

またECSからRDS for MySQLへ接続するためにdocker-composeを使います。docker-composeはコンテナオーケストレーションの一つで、環境構築を再現するのが楽になる手法です。docker-compose.ymlファイルは以下の通りです。

version: '3'
services:
  # MySQL
  db:
    image: mysql:5.7
    container_name: mysql_host
    environment:
     - MYSQL_HOST='rds-sample.mysql.japan.rds.aliyuncs.com'
     - MYSQL_DATABASE='rds_setting_sample'
     - MYSQL_USER='test_user'
     - MYSQL_PASSWORD='!Password2019'
     - TZ='Asia/Tokyo'
    command: mysqld --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
    volumes:
      - ./docker/db/data:/var/lib/mysql
      - ./docker/db/my.cnf:/etc/mysql/conf.d/my.cnf
      - ./docker/db/sql:/docker-entrypoint-initdb.d
    ports:
    - 3306:3306

パラメータ構成

それぞれのパラメータは以下の通りです。

ネットワーク構成:

ECSインスタンスセキュリティグループ構成:

ECSインスタンス構成:

SLB構成:

RDS構成:

ソース

ソースは以下になります。

main.tf

provider "alicloud" {
  access_key = "${var.access_key}"
  secret_key = "${var.secret_key}"
  region = "${var.region}"
}

resource "alicloud_vpc" "vpc" {
  vpc_name = "${var.project_name}-vpc"
  cidr_block = "192.168.1.0/24"
  description = "Enable RDS Setting Sample vpc"
}

resource "alicloud_vswitch" "vsw" {
  vswitch_name      = "${var.project_name}-vswitch"
  vpc_id            = "${alicloud_vpc.vpc.id}"
  cidr_block        = "192.168.1.0/28"
  zone_id           = "${var.zone}"
  description = "Enable RDS Setting Sample vswitch"
}


# DBを作成する
resource "alicloud_db_instance" "db_instance" {
  engine = "MySQL"
  engine_version = "5.7"
  instance_type = "rds.mysql.t1.small"
  instance_storage = 5
  vswitch_id = "${alicloud_vswitch.vsw.id}"
  security_ips = ["192.168.1.0/28"]
}

resource "alicloud_db_database" "default" {
  name = "${var.database_name}"
  instance_id = "${alicloud_db_instance.db_instance.id}"
  character_set = "utf8"
}

resource "alicloud_db_account" "default" {
  db_instance_id = "${alicloud_db_instance.db_instance.id}"
  account_name = "${var.db_user}"
  account_password = "${var.db_password}"
}

resource "alicloud_db_account_privilege" "default" {
  instance_id = "${alicloud_db_instance.db_instance.id}"
  account_name = "${alicloud_db_account.default.name}"
  db_names = ["${alicloud_db_database.default.name}"]
  privilege = "ReadWrite"
}

resource "alicloud_db_connection" "default" {
  instance_id = "${alicloud_db_instance.db_instance.id}"
  connection_prefix = "rds-sample"
  port = "3306"
}


resource "alicloud_security_group" "sg" {
  name   = "${var.project_name}_security_group"
  description = "Enable RDS Setting Sample security group"
  vpc_id = "${alicloud_vpc.vpc.id}"
}

resource "alicloud_security_group_rule" "allow_ssh" {
  type              = "ingress"
  ip_protocol       = "tcp"
  nic_type          = "intranet"
  policy            = "accept"
  port_range        = "22/22"
  priority          = 1
  security_group_id = "${alicloud_security_group.sg.id}"
  cidr_ip           = "0.0.0.0/0"
}

resource "alicloud_security_group_rule" "allow_http" {
  type              = "ingress"
  ip_protocol       = "tcp"
  nic_type          = "intranet"
  policy            = "accept"
  port_range        = "80/80"
  priority          = 1
  security_group_id = "${alicloud_security_group.sg.id}"
  cidr_ip           = "0.0.0.0/0"
}

resource "alicloud_instance" "ECS_instance" {
  instance_name   = "${var.project_name}-ECS-instance"
  host_name   = "${var.project_name}-ECS-instance"
  instance_type   = "ecs.sn1.medium"
  image_id        = "centos_7_04_64_20G_alibase_201701015.vhd"
  system_disk_category = "cloud_efficiency"
  security_groups = ["${alicloud_security_group.sg.id}"]
  availability_zone = "${var.zone}"
  vswitch_id = "${alicloud_vswitch.vsw.id}"
  password = "${var.ecs_password}"
  internet_max_bandwidth_out = 20
  user_data = "${file("provisioning.sh")}"
}

resource "alicloud_slb_load_balancer" "default" {
  load_balancer_name = "${var.project_name}-slb"
  vswitch_id = "${alicloud_vswitch.vsw.id}"
  address_type = "internet"
  internet_charge_type = "paybytraffic"
  load_balancer_spec = "slb.s2.small"
  bandwidth = 5
}

resource "alicloud_slb_listener" "http" {
  load_balancer_id = "${alicloud_slb_load_balancer.default.id}"
  backend_port              = 80
  frontend_port             = 80
  health_check_connect_port = 80
  bandwidth                 = 10
  protocol = "http"
  sticky_session = "on"
  sticky_session_type = "insert"
  cookie = "slblistenercookie"
  cookie_timeout = 86400
}

resource "alicloud_slb_attachment" "default" {
  load_balancer_id = "${alicloud_slb_load_balancer.default.id}"
  instance_ids = ["${alicloud_instance.ECS_instance.id}"]
}

data "template_file" "user_data" {
  template = "${file("provisioning.sh")}"
  vars = {
    DB_HOST_IP = "${alicloud_db_instance.db_instance.connection_string}"
    DB_NAME = "${var.database_name}"
    DB_USER = "${var.db_user}"
    DB_PASSWORD = "${var.db_password}"
  }
}

variables.tf

variable "access_key" {}
variable "secret_key" {}
variable "region" {}
variable "zone" {}
variable "project_name" {}
variable "database_name" {}
variable "ecs_password" {}
variable "db_user" {}
variable "db_password" {}

output.tf

output "ECS_instance_ip" {
  value = "${alicloud_instance.ECS_instance.*.public_ip}"
}
output "slb_ip" {
  value = "${alicloud_slb_load_balancer.default.address}"
}
output "rds_host" {
  value = "${alicloud_db_instance.db_instance.connection_string}"
}

confing.tfvars

access_key = "xxxxxxxxxxxxxxxxxxxx"
secret_key = "xxxxxxxxxxxxxxxxxxxx"
region = "ap-northeast-1"
zone = "ap-northeast-1a"
project_name = "RDS-Setting-Sample-for-Terraform"
database_name = "rds_setting_sample"
ecs_password = "!Password2019"
db_user = "test_user"
db_password = "!Password2019"

provisioning.sh

#!/bin/sh
export MYSQL_HOST=${DB_HOST_IP}
export MYSQL_DATABASE=${DB_NAME}
export MYSQL_USER=${DB_USER}
export MYSQL_PASSWORD=${DB_PASSWORD}

sudo yum install -y yum-utils unzip mysql
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
sudo yum makecache fast
sudo yum install docker-ce
curl -L https://github.com/docker/compose/releases/download/1.24.0/docker-compose-$(uname -s)-$(uname -m) -o /usr/local/bin/docker-compose
chmod +x /usr/local/bin/docker-compose

echo "version: '3'" >> docker-compose.yml
echo "services:" >> docker-compose.yml
echo "  # MySQL" >> docker-compose.yml
echo "  db:" >> docker-compose.yml
echo "    image: mysql:5.7" >> docker-compose.yml
echo "    container_name: mysql_host" >> docker-compose.yml
echo "    environment:" >> docker-compose.yml
echo "     - MYSQL_HOST=db_host" >> docker-compose.yml
echo "     - MYSQL_DATABASE=db_name" >> docker-compose.yml
echo "     - MYSQL_USER=db_user" >> docker-compose.yml
echo "     - MYSQL_PASSWORD=db_password" >> docker-compose.yml
echo "     - TZ='Asia/Tokyo'" >> docker-compose.yml
echo "    command: mysqld --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci" >> docker-compose.yml
echo "    volumes:" >> docker-compose.yml
echo "      - ./docker/db/data:/var/lib/mysql" >> docker-compose.yml
echo "      - ./docker/db/my.cnf:/etc/mysql/conf.d/my.cnf" >> docker-compose.yml
echo "      - ./docker/db/sql:/docker-entrypoint-initdb.d" >> docker-compose.yml
echo "    ports:" >> docker-compose.yml
echo "    - 3306:3306" >> docker-compose.yml
sed -i "s/=db_host/='$MYSQL_HOST'/g" docker-compose.yml
sed -i "s/=db_name/='$MYSQL_DATABASE'/g" docker-compose.yml
sed -i "s/=db_user/='$MYSQL_USER'/g" docker-compose.yml
sed -i "s/=db_password/='$MYSQL_PASSWORD'/g" docker-compose.yml

sudo service docker start
docker-compose up -d

実行

  ソースの準備ができたら実行します。

terraform init
terraform plan -var-file="confing.tfvars"
terraform apply -var-file="confing.tfvars"

これで完了です。問題なく実行できたら、ECSとSLBそれぞれのIP、DBのhostが表示されます。 DBのhostはECSから手動接続するにあたり必要なのでメモを残してください。

alicloud_db_account_privilege.default: Creation complete after 2m29s (ID: rm-e9b9hkm8u33h8cd3x:test_user:ReadWrite)
alicloud_db_connection.default: Creation complete after 2m32s (ID: rm-e9b9hkm8u33h8cd3x:rds-sample)
data.template_file.user_data: Refreshing state...

Apply complete! Resources: 14 added, 0 changed, 0 destroyed.

Outputs:

ECS_instance_ip = [
    47.74.52.124
]
rds_host = rm-e9b9hkm8u33h8cd3x.mysql.japan.rds.aliyuncs.com
slb_ip = 47.74.1.41
$

それではECSに入り、RDSへ接続してみます。先ほどのDB host名が必要になります。

$ ssh root@47.74.52.124
The authenticity of host '47.74.52.124 (47.74.52.124)' can't be established.
ECDSA key fingerprint is SHA256:XaQ96OPhtGZQPyQXlYin5qF+cqxS2Arle41wTqkOinE.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '47.74.52.124' (ECDSA) to the list of known hosts.
root@47.74.52.124's password:

Welcome to Alibaba Cloud Elastic Compute Service !

[root@RDS-Setting-Sample-for-Terraform-ECS-instance ~]#
[root@RDS-Setting-Sample-for-Terraform-ECS-instance ~]# mysql --version
mysql  Ver 15.1 Distrib 5.5.60-MariaDB, for Linux (x86_64) using readline 5.1
[root@RDS-Setting-Sample-for-Terraform-ECS-instance ~]#
[root@RDS-Setting-Sample-for-Terraform-ECS-instance ~]#
[root@RDS-Setting-Sample-for-Terraform-ECS-instance ~]# mysql -u test_user -p -h rm-e9b9hkm8u33h8cd3x.mysql.japan.rds.aliyuncs.com
Enter password:
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 51312248
Server version: 5.5.18.1 Source distribution

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MySQL [(none)]>
MySQL [(none)]> exit;
Bye
[root@RDS-Setting-Sample-for-Terraform-ECS-instance ~]#

無事MySQLへ接続できたことを確認できました。

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