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第一階段 — 建置

第一階段使用 Terraform 在 F5 Distributed Cloud 上部署具有權威性的主要 DNS 區域,並以 Azure Blob Storage 作為遠端狀態儲存後端。本頁說明計畫中的每個檔案、解釋必要的變數與密鑰,並涵蓋本機執行與 GitHub Actions 管線兩種方式。

  • system 命名空間中為您委派的網域建立一個 xcsh_dns_zone,並包含一個 demo-records 群組的 A 記錄(wwwappapi)。
  • Terraform 狀態儲存於 Azure Blob Storage 容器中,讓您的本機與 CI 環境共享相同的狀態。

計畫位於 terraform/ 目錄下:一個精簡的根模組,負責將輸入傳入 dns-zone 模組。

固定 Terraform 及提供者的版本。提供者版本限制為 >= 3.62.0 — 此版本開始,僅限系統使用的 DNS 資源會自動預設其命名空間。

terraform {
required_version = ">= 1.5"
required_providers {
xcsh = {
source = "f5-sales-demo/xcsh"
# >= 3.62.0: the namespace attribute for system-only DNS resources defaults
# to "system" (spec-driven), so it can be omitted. Locally the provider is
# consumed via dev_overrides, which ignores this constraint.
version = ">= 3.62.0"
}
}
}

提供者在程式碼中不帶任何參數 — 它從環境變數進行驗證,因此不會有密鑰被提交至版本庫。

# The xcsh provider authenticates from the environment — no secrets in code.
# Export one of the following credential sets before running Terraform:
#
# Token auth: XCSH_API_URL + XCSH_API_TOKEN
# P12 auth: XCSH_API_URL + XCSH_P12_FILE + XCSH_P12_PASSWORD
# PEM auth: XCSH_API_URL + XCSH_CERT + XCSH_KEY
#
# See terraform/README.md for local dev setup (dev_overrides + env).
provider "xcsh" {}

一個部分azurerm 後端設定:不在此處寫死任何環境特定的值。座標資訊在 init 時提供(來自本機檔案,或在 CI 中來自 GitHub Actions 變數)。

terraform {
# Azure Blob Storage remote state, configured as a PARTIAL backend:
# no environment-specific values are hardcoded here. Supply them at init time.
#
# CI: terraform init -backend-config="resource_group_name=$RG" ...
# (values from GitHub Actions repository variables)
# Local: terraform init -backend-config=backend.hcl (copy backend.hcl.example; gitignored)
#
# Auth is the storage account access key via the ARM_ACCESS_KEY environment
# variable (never committed). Keyless auth (use_oidc / use_azuread_auth) is not
# used: our Contributor-only RBAC cannot assign the "Storage Blob Data
# Contributor" role those methods require.
backend "azurerm" {}
}

domain 為必填項目(在執行時提供,不寫死);a_records 將每個記錄名稱對應至其 IPv4 位址。此處沒有 namespace 變數 — 提供者依據 API 規格的限制,將 DNS 物件固定至 system 命名空間,因此無需在此設定。

variable "domain" {
description = "DNS zone FQDN (required; supplied via TF_VAR_domain / a GitHub variable / tfvars)."
type = string
}
variable "labels" {
description = "Labels applied to managed DNS objects."
type = map(string)
default = {
managed_by = "terraform"
use_case = "dns"
}
}
variable "a_records" {
description = "A records: record name (\"\" = apex) to list of IPv4 addresses."
type = map(list(string))
default = {
www = ["203.0.113.10"]
app = ["203.0.113.20"]
api = ["203.0.113.30"]
}
}

根模組將輸入傳入 ./modules/dns-zone

module "dns_zone" {
source = "./modules/dns-zone"
domain = var.domain
labels = var.labels
a_records = var.a_records
}

該模組負責建立區域(命名空間已省略 — 提供者預設為 system)。一個 dynamic "rr_set" 區塊將 a_records 對應表轉換為每個項目一組記錄集:

resource "xcsh_dns_zone" "this" {
name = var.domain
labels = var.labels
primary {
default_soa_parameters {}
rr_set_group {
metadata {
name = "demo-records"
}
dynamic "rr_set" {
for_each = var.a_records
content {
ttl = var.record_ttl
a_record {
name = rr_set.key
values = rr_set.value
}
}
}
}
}
}

根目錄的 outputs.tf 從模組重新匯出區域名稱與 F5 XC 識別碼。

.tf 檔案中不內嵌任何環境特定的資訊。所有內容均在執行時提供 — 在 CI 中來自 GitHub Actions 的變數密鑰,或在本機來自本機檔案及環境變數。

用途CI 來源本機來源
resource_group_namestorage_account_namecontainer_namekeyazurerm 後端座標儲存庫變數 TFSTATE_RESOURCE_GROUPTFSTATE_STORAGE_ACCOUNTTFSTATE_CONTAINERTFSTATE_KEY(透過 -backend-config 傳入)backend.hcl(複製自 backend.hcl.example;已加入 gitignore)
domainTerraform 輸入值儲存庫變數 DNS_DOMAIN(作為 TF_VAR_domainterraform.tfvars(複製範例檔案)或 TF_VAR_domain
ARM_ACCESS_KEYazurerm 後端驗證(儲存帳戶金鑰)儲存庫密鑰export ARM_ACCESS_KEY=...
XCSH_API_URLXCSH_API_TOKENxcsh 提供者驗證儲存庫密鑰export XCSH_API_URL=... XCSH_API_TOKEN=...

儲存庫中附帶的兩個範例檔案:

resource_group_name = "f5-sales-demo-tfstate"
storage_account_name = "f5salesdemotfstate"
container_name = "tfstate"
key = "dns.tfstate"

後端儲存無法儲存其自身的啟動設定,因此需透過已驗證的 Azure CLI 工作階段,在帶外一次性建立。儲存庫附帶 scripts/bootstrap-azure-state.sh

Terminal window
az group create --name f5-sales-demo-tfstate --location eastus2 \
--tags managed_by=terraform use_case=dns purpose=tfstate
az storage account create --name f5salesdemotfstate --resource-group f5-sales-demo-tfstate \
--location eastus2 --sku Standard_LRS --kind StorageV2 \
--min-tls-version TLS1_2 --allow-blob-public-access false
# State safety: keep prior versions and allow recovery of deleted state blobs.
az storage account blob-service-properties update \
--account-name f5salesdemotfstate --resource-group f5-sales-demo-tfstate \
--enable-versioning true \
--enable-delete-retention true --delete-retention-days 7 \
--enable-container-delete-retention true --container-delete-retention-days 7
KEY="$(az storage account keys list \
--account-name f5salesdemotfstate --resource-group f5-sales-demo-tfstate \
--query '[0].value' -o tsv)"
az storage container create --name tfstate \
--account-name f5salesdemotfstate --auth-mode key --account-key "$KEY"

接著匯出金鑰供本機執行使用,並將其(連同提供者憑證)設定為 GitHub 密鑰:

Terminal window
export ARM_ACCESS_KEY="$KEY"
gh secret set ARM_ACCESS_KEY -R f5-sales-demo/dns
gh secret set XCSH_API_URL -R f5-sales-demo/dns
gh secret set XCSH_API_TOKEN -R f5-sales-demo/dns
  1. 設定輸入值。 複製範例檔案並填入您的值:

    Terminal window
    cp terraform/backend.hcl.example terraform/backend.hcl
    cp terraform/terraform.tfvars.example terraform/terraform.tfvars
  2. 匯出憑證:

    Terminal window
    export XCSH_API_URL="https://<tenant>.console.ves.volterra.io"
    export XCSH_API_TOKEN="<api-token>"
    export ARM_ACCESS_KEY="<storage-account-key>"
  3. 使用部分設定初始化後端:

    Terminal window
    cd terraform
    terraform init -backend-config=backend.hcl
  4. 檢查格式並驗證:

    Terminal window
    terraform fmt -check -recursive
    terraform validate
  5. 計畫並套用:

    Terminal window
    terraform plan
    terraform apply

成功套用後,系統會建立區域並將狀態寫入 Azure 容器。請繼續前往第二階段 — 驗證以確認解析是否正常運作。

.github/workflows/terraform.yml 工作流程會在每次拉取請求時執行計畫,並在合併至 main 時執行套用。它從儲存庫變數讀取後端座標與輸入值,從密鑰讀取憑證,並僅將每個值注入至需要它的步驟中,同時透過並行群組序列化執行,確保兩個套用操作不會同時競爭共享的狀態 blob。

name: Terraform
on:
pull_request:
branches: [main]
paths: ['terraform/**', '.github/workflows/terraform.yml']
push:
branches: [main]
paths: ['terraform/**']
permissions:
contents: read
concurrency:
group: terraform-state
cancel-in-progress: false
env:
TF_IN_AUTOMATION: 'true'
jobs:
terraform:
name: ${{ github.event_name == 'push' && 'apply' || 'plan' }}
runs-on: ubuntu-latest
defaults:
run:
working-directory: terraform
steps:
- name: Checkout
uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
- name: Setup Terraform
uses: hashicorp/setup-terraform@dfe3c3f87815947d99a8997f908cb6525fc44e9e # v4.0.1
- name: Init
env:
ARM_ACCESS_KEY: ${{ secrets.ARM_ACCESS_KEY }}
RESOURCE_GROUP: ${{ vars.TFSTATE_RESOURCE_GROUP }}
STORAGE_ACCOUNT: ${{ vars.TFSTATE_STORAGE_ACCOUNT }}
CONTAINER: ${{ vars.TFSTATE_CONTAINER }}
STATE_KEY: ${{ vars.TFSTATE_KEY }}
run: |
terraform init -input=false \
-backend-config="resource_group_name=${RESOURCE_GROUP}" \
-backend-config="storage_account_name=${STORAGE_ACCOUNT}" \
-backend-config="container_name=${CONTAINER}" \
-backend-config="key=${STATE_KEY}"
- name: Format check
run: terraform fmt -check -recursive
- name: Validate
run: terraform validate -no-color
- name: Plan
if: github.event_name == 'pull_request'
env:
ARM_ACCESS_KEY: ${{ secrets.ARM_ACCESS_KEY }}
XCSH_API_URL: ${{ secrets.XCSH_API_URL }}
XCSH_API_TOKEN: ${{ secrets.XCSH_API_TOKEN }}
TF_VAR_domain: ${{ vars.DNS_DOMAIN }}
run: terraform plan -input=false -no-color
- name: Apply
if: github.event_name == 'push'
env:
ARM_ACCESS_KEY: ${{ secrets.ARM_ACCESS_KEY }}
XCSH_API_URL: ${{ secrets.XCSH_API_URL }}
XCSH_API_TOKEN: ${{ secrets.XCSH_API_TOKEN }}
TF_VAR_domain: ${{ vars.DNS_DOMAIN }}
run: terraform apply -input=false -auto-approve -no-color

Actions 已固定至提交 SHA(並附有版本註解),密鑰的作用域限定於 initplanapply 步驟,而非整個工作。