Cloud Enterprise Network：使用企業版轉寄路由器實現流量安全互訪

第一步：建立資源

本文情境對應的Terraform代碼如下：

variable "pname" {
  description = "The prefix name for the resources"
  type        = string
  default     = "tf-CenSec"
}
variable "default_region" {
  description = "Default region"
  type        = string
  default     = "cn-hangzhou"
}
variable "az" {
  description = "List of availability zones to use"
  type        = list(string)
  default     = ["cn-hangzhou-i", "cn-hangzhou-j", "cn-hangzhou-k"]
}
variable "vpc_count" {
  description = "Number of VPCs to create"
  type        = number
  default     = 3
}
provider "alicloud" {
  region = var.default_region
}
# vpc
resource "alicloud_vpc" "main" {
  count      = var.vpc_count
  vpc_name   = "${var.pname}-vpc${count.index + 1}"
  cidr_block = "10.${count.index}.0.0/16"
}
# vsw
resource "alicloud_vswitch" "main" {
  count        = var.vpc_count * length(var.az)
  vpc_id       = alicloud_vpc.main[floor(count.index / length(var.az))].id
  cidr_block   = "10.${floor(count.index / length(var.az))}.${count.index % length(var.az)}.0/24"
  zone_id      = var.az[count.index % length(var.az)]
  vswitch_name = "${var.pname}-vsw${count.index + 1}"
}
# ecs
resource "alicloud_instance" "main" {
  count                = var.vpc_count
  instance_name        = "${var.pname}-ecs${count.index + 1}"
  instance_type        = "ecs.e-c1m1.large"
  security_groups      = [alicloud_security_group.main[count.index].id]
  vswitch_id           = alicloud_vswitch.main[count.index * length(var.az)].id
  image_id             = "aliyun_3_x64_20G_qboot_alibase_20230727.vhd"
  system_disk_category = "cloud_essd"
  private_ip           = "10.${count.index}.0.1"
  instance_charge_type = "PostPaid"
  user_data = base64encode(<<-EOT
    #!/bin/bash
    ${count.index == 0 ? "echo 1 > /proc/sys/net/ipv4/ip_forward" : ""} 
    yum install -y traceroute
    yum install -y mtr
  EOT
  ) # ecs1 enable ip_forward
}
# sg
resource "alicloud_security_group" "main" {
  count               = var.vpc_count
  security_group_name = "${var.pname}-${count.index + 1}"
  vpc_id              = alicloud_vpc.main[count.index].id
}
resource "alicloud_security_group_rule" "allow_inbound_ssh" {
  count             = var.vpc_count
  type              = "ingress"
  ip_protocol       = "tcp"
  nic_type          = "intranet"
  policy            = "accept"
  port_range        = "22/22"
  priority          = 1
  security_group_id = alicloud_security_group.main[count.index].id
  cidr_ip           = "0.0.0.0/0"
}
resource "alicloud_security_group_rule" "allow_inbound_icmp" {
  count             = var.vpc_count
  type              = "ingress"
  ip_protocol       = "icmp"
  nic_type          = "intranet"
  policy            = "accept"
  port_range        = "-1/-1"
  priority          = 1
  security_group_id = alicloud_security_group.main[count.index].id
  cidr_ip           = "0.0.0.0/0"
}
resource "alicloud_security_group_rule" "allow_all_outbound" {
  count             = var.vpc_count
  type              = "egress"
  ip_protocol       = "tcp"
  nic_type          = "intranet"
  policy            = "accept"
  port_range        = "1/65535"
  priority          = 1
  security_group_id = alicloud_security_group.main[count.index].id
  cidr_ip           = "0.0.0.0/0"
}
# cen
resource "alicloud_cen_instance" "cen1" {
  cen_instance_name = var.pname
}
# tr
resource "alicloud_cen_transit_router" "tr1" {
  transit_router_name = var.pname
  cen_id              = alicloud_cen_instance.cen1.id
}
# attach1  to vsw2 vsw3 in vpc1
resource "alicloud_cen_transit_router_vpc_attachment" "attach1" {
  cen_id            = alicloud_cen_instance.cen1.id
  transit_router_id = alicloud_cen_transit_router.tr1.transit_router_id
  vpc_id            = alicloud_vpc.main[0].id
  zone_mappings {
    zone_id    = var.az[1]
    vswitch_id = alicloud_vswitch.main[1].id # vsw2, vpc1-2
  }
  zone_mappings {
    zone_id    = var.az[2]
    vswitch_id = alicloud_vswitch.main[2].id # vsw3, vpc1-3
  }
  transit_router_vpc_attachment_name = "attach1"
}
# attach2 to vsw1 vsw2 in vpc2
resource "alicloud_cen_transit_router_vpc_attachment" "attach2" {
  cen_id            = alicloud_cen_instance.cen1.id
  transit_router_id = alicloud_cen_transit_router.tr1.transit_router_id
  vpc_id            = alicloud_vpc.main[1].id
  zone_mappings {
    zone_id    = var.az[0]
    vswitch_id = alicloud_vswitch.main[3].id # vsw4, vpc2-1
  }
  zone_mappings {
    zone_id    = var.az[1]
    vswitch_id = alicloud_vswitch.main[4].id # vsw5, vpc2-2
  }
  transit_router_vpc_attachment_name = "attach2"
}
# attach3 to vsw1 vsw2 in vpc3
resource "alicloud_cen_transit_router_vpc_attachment" "attach3" {
  cen_id            = alicloud_cen_instance.cen1.id
  transit_router_id = alicloud_cen_transit_router.tr1.transit_router_id
  vpc_id            = alicloud_vpc.main[2].id
  zone_mappings {
    zone_id    = var.az[0]
    vswitch_id = alicloud_vswitch.main[6].id # vsw6, vpc3-1
  }
  zone_mappings {
    zone_id    = var.az[1]
    vswitch_id = alicloud_vswitch.main[7].id # vsw7, vpc3-2
  }
  transit_router_vpc_attachment_name = "attach3"
}
# 2 rt for vpc1
resource "alicloud_route_table" "rt" {
  count            = 2
  vpc_id           = alicloud_vpc.main[0].id
  route_table_name = "${var.pname}-rt${count.index}"
  associate_type   = "VSwitch"
}
# 2 rt attach， rt1 to vsw1， rt2 to vsw2、vsw3
locals {
  # rt and vsw map
  rt_attachments = {
    "rt1_vsw1" = {
      route_table_index = 0
      vswitch_index     = 0
    }
    "rt2_vsw2" = {
      route_table_index = 1
      vswitch_index     = 1
    }
    "rt2_vsw3" = {
      route_table_index = 1
      vswitch_index     = 2
    }
  }
}
resource "alicloud_route_table_attachment" "rt_attach" {
  for_each = local.rt_attachments
  vswitch_id     = alicloud_vswitch.main[each.value.vswitch_index].id
  route_table_id = alicloud_route_table.rt[each.value.route_table_index].id
}
# rt entry, vpc1
resource "alicloud_route_entry" "rt-entry1" { # nexthop tr
  route_table_id        = alicloud_route_table.rt[0].id
  destination_cidrblock = "0.0.0.0/0"
  nexthop_type          = "Attachment"
  nexthop_id            = alicloud_cen_transit_router_vpc_attachment.attach1.transit_router_attachment_id
}
resource "alicloud_route_entry" "rt-entry2" { # nexthop ecs1
  route_table_id        = alicloud_route_table.rt[1].id
  destination_cidrblock = "0.0.0.0/0"
  nexthop_type          = "Instance"
  nexthop_id            = alicloud_instance.main[0].id # ecs1
}
# rt entry, vpc2 vpc3
resource "alicloud_route_entry" "rt-entry4" {
  route_table_id        = alicloud_vpc.main[1].route_table_id
  destination_cidrblock = "0.0.0.0/0"
  nexthop_type          = "Attachment"
  nexthop_id            = alicloud_cen_transit_router_vpc_attachment.attach2.transit_router_attachment_id
}
resource "alicloud_route_entry" "rt-entry5" {
  route_table_id        = alicloud_vpc.main[2].route_table_id
  destination_cidrblock = "0.0.0.0/0"
  nexthop_type          = "Attachment"
  nexthop_id            = alicloud_cen_transit_router_vpc_attachment.attach3.transit_router_attachment_id
}
# new 2 tr_rt
resource "alicloud_cen_transit_router_route_table" "tr_rt1" {
  transit_router_id               = alicloud_cen_transit_router.tr1.transit_router_id
  transit_router_route_table_name = "tr_rt1"
}
resource "alicloud_cen_transit_router_route_table" "tr_rt2" {
  transit_router_id               = alicloud_cen_transit_router.tr1.transit_router_id
  transit_router_route_table_name = "tr_rt2"
}
# ass rt1 attach2 3
resource "alicloud_cen_transit_router_route_table_association" "ass1" {
  transit_router_route_table_id = alicloud_cen_transit_router_route_table.tr_rt1.transit_router_route_table_id
  transit_router_attachment_id  = alicloud_cen_transit_router_vpc_attachment.attach2.transit_router_attachment_id
}
resource "alicloud_cen_transit_router_route_table_association" "ass2" {
  transit_router_route_table_id = alicloud_cen_transit_router_route_table.tr_rt1.transit_router_route_table_id
  transit_router_attachment_id  = alicloud_cen_transit_router_vpc_attachment.attach3.transit_router_attachment_id
}
# ass rt2 attach1
resource "alicloud_cen_transit_router_route_table_association" "ass3" {
  transit_router_route_table_id = alicloud_cen_transit_router_route_table.tr_rt2.transit_router_route_table_id
  transit_router_attachment_id  = alicloud_cen_transit_router_vpc_attachment.attach1.transit_router_attachment_id
}
# tr_rt_entry
resource "alicloud_cen_transit_router_route_entry" "tr_rt1_entry1" {
  transit_router_route_table_id                     = alicloud_cen_transit_router_route_table.tr_rt1.transit_router_route_table_id
  transit_router_route_entry_destination_cidr_block = "0.0.0.0/0"
  transit_router_route_entry_next_hop_type          = "Attachment"
  transit_router_route_entry_next_hop_id            = alicloud_cen_transit_router_vpc_attachment.attach1.transit_router_attachment_id
}
resource "alicloud_cen_transit_router_route_entry" "tr_rt2_entry1" {
  transit_router_route_table_id                     = alicloud_cen_transit_router_route_table.tr_rt2.transit_router_route_table_id
  transit_router_route_entry_destination_cidr_block = "10.1.0.0/16"
  transit_router_route_entry_next_hop_type          = "Attachment"
  transit_router_route_entry_next_hop_id            = alicloud_cen_transit_router_vpc_attachment.attach2.transit_router_attachment_id
}
resource "alicloud_cen_transit_router_route_entry" "tr_rt2_entry2" {
  transit_router_route_table_id                     = alicloud_cen_transit_router_route_table.tr_rt2.transit_router_route_table_id
  transit_router_route_entry_destination_cidr_block = "10.2.0.0/16"
  transit_router_route_entry_next_hop_type          = "Attachment"
  transit_router_route_entry_next_hop_id            = alicloud_cen_transit_router_vpc_attachment.attach3.transit_router_attachment_id
}
output "ecs1_login_address" {
  value = "https://ecs-workbench.aliyun.com/?from=EcsConsole&instanceType=ecs&regionId=${var.default_region}&instanceId=${alicloud_instance.main[0].id}"
}
output "ecs2_login_address" {
  value = "https://ecs-workbench.aliyun.com/?from=EcsConsole&instanceType=ecs&regionId=${var.default_region}&instanceId=${alicloud_instance.main[1].id}"
}
output "ecs3_login_address" {
  value = "https://ecs-workbench.aliyun.com/?from=EcsConsole&instanceType=ecs&regionId=${var.default_region}&instanceId=${alicloud_instance.main[2].id}"
}

第二步：驗證測試

1. 登入ECS2執行個體（名稱為tf-CenSec-ecs2）：

   您可以在Terraform的Outputs輸出中，找到ECS2的登入地址並複製到瀏覽器開啟，登入時注意認證方式選擇臨時SSH密鑰認證。

   Terraform 執行完成後，輸出樣本如下，其中 ecs2_login_address 即為 ECS2 的登入地址。

   Outputs:
   ecs1_login_address = "https://ecs-workbench.aliyun.com/?from=EcsConsole&instanceType=ecs&regionId=cn-hangzhou&instanceId=i-bp1xxx"
   ecs2_login_address = "https://ecs-workbench.aliyun.com/?from=EcsConsole&instanceType=ecs&regionId=cn-hangzhou&instanceId=i-bp1xxx"
   ecs3_login_address = "https://ecs-workbench.aliyun.com/?from=EcsConsole&instanceType=ecs&regionId=cn-hangzhou&instanceId=i-bp1xxx"

2. 在ECS2執行mtr命令，測試ECS2到ECS3的流量路徑：

   mtr 10.2.0.1 -i 5

   參數說明：-i 5指的是每5秒發送一次ping請求。

   My traceroute  [v0.92]
   iZbp1xxx (10.1.0.1)                          2024-12-04T20:40:46+0800
   Keys:  Help   Display mode   Restart statistics   Order of fields   quit
                                            Packets               Pings
    Host                                  Loss%   Snt   Last   Avg  Best  Wrst StDev
    1. 10.0.0.1                            0.0%     9    3.8   3.8   3.8   4.1   0.1
    2. 10.0.0.1                            0.0%     9    5.0   4.0   3.8   5.0   0.4
    3. 10.2.0.1                            0.0%     9    8.2   8.3   8.2   8.6   0.1

   結果顯示，從ECS2發往ECS3的報文，經過了10.0.0.1（ECS1）轉寄，表明VPC2和VPC3之間互訪的流量已經繞行ECS1（安全ECS）。

第三步：釋放資源

驗證完畢後，如果您不再使用資源，請執行以下命令釋放資源，防止繼續計費。

terraform destroy --auto-approve