以 Terraform 供基

實基為碼以 Terraform 供、版、管雲資於 AWS、Azure、GCP 等。

用

• 供新雲基（VPC、算、儲、庫）→用
• 自 ClickOps 或 CloudFormation 遷至宣 IaC→用
• 管多環基（dev、staging、prod）→用
• 跨團實可重基式→用
• 與應碼共版基變→用
• 過可重模強基準→用

入

• 必：Terraform CLI 裝（terraform --version）
• 必：雲憑（AWS、Azure、GCP 服戶）
• 必：遠態後配（S3、Azure Storage、Terraform Cloud）
• 可：欲入或遷之現基
• 可：團共之 Terraform Cloud/Enterprise
• 可：驗式之預提鉤

行

見 Extended Examples 為完配檔與模。

一：始 Terraform 案構

立組目構含後配與供設。

# Create project structure
mkdir -p terraform/{modules,environments/{dev,staging,prod}}
cd terraform

# Create backend configuration
cat > backend.tf <<'EOF'
terraform {
  required_version = ">= 1.6"

  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }

  backend "s3" {
    bucket         = "my-terraform-state"
    key            = "infrastructure/terraform.tfstate"
    region         = "us-east-1"
    encrypt        = true
    dynamodb_table = "terraform-lock"

    # Workspace-specific state files
    workspace_key_prefix = "env"
  }
}

provider "aws" {
  region = var.aws_region

  default_tags {
    tags = {
      ManagedBy   = "Terraform"
      Environment = terraform.workspace
      Project     = var.project_name
    }
  }
}
EOF

# Create variables file
cat > variables.tf <<'EOF'
variable "aws_region" {
  description = "AWS region for resources"
  type        = string
  default     = "us-east-1"
}

variable "project_name" {
  description = "Project name for resource naming and tagging"
  type        = string
  validation {
    condition     = length(var.project_name) > 0 && length(var.project_name) <= 32
    error_message = "Project name must be 1-32 characters"
  }
}

variable "environment" {
  description = "Environment name (dev, staging, prod)"
  type        = string
  validation {
    condition     = contains(["dev", "staging", "prod"], var.environment)
    error_message = "Environment must be dev, staging, or prod"
  }
}
EOF

# Initialize Terraform
terraform init

得：Terraform 始成、下供件、配遠後。.terraform/ 目立含供二進。態後連驗。

敗：後始敗→驗 S3 桶在、IAM 許 s3:GetObject、s3:PutObject、dynamodb:GetItem、dynamodb:PutItem。供下敗→察網與企代設。terraform init -upgrade 更供。

二：立可重基模

建組模為 VPC、算、資基含入驗。

# modules/vpc/main.tf
variable "vpc_cidr" {
  description = "CIDR block for VPC"
  type        = string
  default     = "10.0.0.0/16"
}

variable "availability_zones" {
  description = "List of AZs to use"
  type        = list(string)
}

variable "project_name" {
  description = "Project name for resource naming"
  type        = string
}

variable "environment" {
  description = "Environment name"
  type        = string
}

locals {
  common_tags = {
    Project     = var.project_name
    Environment = var.environment
    Module      = "vpc"
  }
}

resource "aws_vpc" "main" {
  cidr_block           = var.vpc_cidr
  enable_dns_hostnames = true
  enable_dns_support   = true

  tags = merge(local.common_tags, {
    Name = "${var.project_name}-${var.environment}-vpc"
  })
}

resource "aws_subnet" "public" {
  count             = length(var.availability_zones)
  vpc_id            = aws_vpc.main.id
  cidr_block        = cidrsubnet(var.vpc_cidr, 8, count.index)
  availability_zone = var.availability_zones[count.index]

  map_public_ip_on_launch = true

  tags = merge(local.common_tags, {
    Name = "${var.project_name}-${var.environment}-public-${var.availability_zones[count.index]}"
    Type = "public"
  })
}

resource "aws_subnet" "private" {
  count             = length(var.availability_zones)
  vpc_id            = aws_vpc.main.id
  cidr_block        = cidrsubnet(var.vpc_cidr, 8, count.index + 100)
  availability_zone = var.availability_zones[count.index]

  tags = merge(local.common_tags, {
    Name = "${var.project_name}-${var.environment}-private-${var.availability_zones[count.index]}"
    Type = "private"
  })
}

resource "aws_internet_gateway" "main" {
  vpc_id = aws_vpc.main.id

  tags = merge(local.common_tags, {
    Name = "${var.project_name}-${var.environment}-igw"
  })
}

resource "aws_eip" "nat" {
  count  = length(var.availability_zones)
  domain = "vpc"

  tags = merge(local.common_tags, {
    Name = "${var.project_name}-${var.environment}-nat-eip-${var.availability_zones[count.index]}"
  })

  depends_on = [aws_internet_gateway.main]
}

resource "aws_nat_gateway" "main" {
  count         = length(var.availability_zones)
  allocation_id = aws_eip.nat[count.index].id
  subnet_id     = aws_subnet.public[count.index].id

  tags = merge(local.common_tags, {
    Name = "${var.project_name}-${var.environment}-nat-${var.availability_zones[count.index]}"
  })

  depends_on = [aws_internet_gateway.main]
}

# modules/vpc/outputs.tf
output "vpc_id" {
  description = "VPC ID"
  value       = aws_vpc.main.id
}

output "public_subnet_ids" {
  description = "List of public subnet IDs"
  value       = aws_subnet.public[*].id
}

output "private_subnet_ids" {
  description = "List of private subnet IDs"
  value       = aws_subnet.private[*].id
}

output "nat_gateway_ips" {
  description = "List of NAT Gateway public IPs"
  value       = aws_eip.nat[*].public_ip
}

得：模立 VPC 含跨多 AZ 之公/私子網、網關、含 EIP 之 NAT 關。出值露資 ID 為下游模。

敗：CIDR 疊誤→調 cidrsubnet() 算或驗 VPC CIDR 不衝現網。依誤→驗 depends_on 塊確正資立序。terraform graph | dot -Tpng > graph.png 視依。

三：實環特配

立環工區含變覆與資源。

# environments/prod/main.tf
terraform {
  required_version = ">= 1.6"
}

# Import shared backend and provider config
# ... (see EXAMPLES.md for complete configuration)

得：環特配立產級含 3 AZ、大實型、產安設。資源解末 AMI。模檔渲含環變。

敗：工區誤→terraform workspace new prod 立。資源敗→驗 AWS 憑有 ec2:DescribeImages 許。模渲誤→驗變型合模期。

四：行計與施程

行 Terraform 計、察變、施含批程。

# Format code
terraform fmt -recursive

# Validate configuration
terraform validate

# ... (see EXAMPLES.md for complete configuration)

為自 CI/CD 整：

# .github/workflows/terraform.yml
name: Terraform

on:
  pull_request:
    paths:
# ... (see EXAMPLES.md for complete configuration)

得：計示資加/變/除。無漂察。施立/更資無誤。出含預值。CI 程於 PR 注計、合主時自施。

敗：計敗→terraform validate 捉法誤。態鎖誤→aws dynamodb get-item --table-name terraform-lock --key '{"LockID":{"S":"terraform-state-bucket/key"}}' 識持者、陳則強解。施敗→察 CloudWatch 為供特誤。terraform show 察今態。

五：管態與實漂察

配態鎖、備、自漂察。

# Create DynamoDB table for state locking
cat > state-backend.tf <<'EOF'
resource "aws_dynamodb_table" "terraform_lock" {
  name           = "terraform-lock"
  billing_mode   = "PAY_PER_REQUEST"
  hash_key       = "LockID"
# ... (see EXAMPLES.md for complete configuration)

為自漂察：

# Create drift detection script
cat > scripts/detect-drift.sh <<'EOF'
#!/bin/bash
set -euo pipefail

cd terraform
# ... (see EXAMPLES.md for complete configuration)

得：態後配含版與密。漂察識帶外變。態操（list、show、mv、import）行無誤。自漂察按時行而發警。

敗：態鎖逾時→驗 DynamoDB 表在含正鍵綱。版誤→aws s3api get-bucket-versioning --bucket bucket-name 察 S3 桶版態。入敗→驗資存且 Terraform 配合實資屬。

六：實模試與文

加 Terratest 自試而生文。

// test/vpc_test.go
package test

import (
    "testing"

# ... (see EXAMPLES.md for complete configuration)

生文：

# Install terraform-docs
go install github.com/terraform-docs/terraform-docs@latest

# Generate module documentation
terraform-docs markdown table modules/vpc > modules/vpc/README.md

# ... (see EXAMPLES.md for complete configuration)

得：Terratest 驗模立期資含正配。文自變述與出定生。預提鉤強提前式與驗。

敗：Terratest 敗→察 AWS 憑與配。長試→t.Parallel() 並。文生誤→驗諸變有 description 屬。預提敗→手 terraform fmt 並修驗誤。

驗

• 後配含密、版、態鎖
• 諸模有入驗與出值
• 工區隔環特態
• 施後 terraform plan 無未期變
• 漂察自行而於變時警
• 模以 Terratest 或類框試
• 文自生而新
• 密由 AWS Secrets Manager 管、非硬碼
• 本估整（Infracost 或類）
• 各環獨態以減爆半徑

忌

• 硬碼值：避硬碼 AMI ID、AZ、戶特值。用資源與變

• 缺生命塊：資意外重立。加 lifecycle { create_before_destroy = true } 防更時停

• 無態鎖：並施壞態。S3 後必用 DynamoDB 表為鎖

• 過寬 IAM：Terraform 服戶有全管。實最少權於管資

• 無版限：供更破基。version = "~> 5.0" 限釘供版

• 態中密：感值存於明態檔。出用 sensitive = true、密存於 AWS Secrets Manager、由資源引

• 無備策：態檔失或壞無復計。S3 版啟、定期態備、試復程

• 單塊配：單態檔管全基。分為邏界（網、算、資）以減爆半徑

參

• configure-git-repository - Terraform 碼之版控
• build-ci-cd-pipeline - 含 GitHub Actions 之自 Terraform 程
• implement-gitops-workflow - ArgoCD/Flux 與 Terraform 整
• manage-kubernetes-secrets - Terraform 供之集中之密管
• deploy-to-kubernetes - Terraform Kubernetes 供用