terraform

Terraform 基础设施即代码

概述

HCL 编写、状态管理、模块开发等技能。

基础命令

# 初始化
terraform init
terraform init -upgrade             # 升级 provider

# 格式化
terraform fmt
terraform fmt -recursive

# 验证
terraform validate

# 计划
terraform plan
terraform plan -out=plan.tfplan

# 应用
terraform apply
terraform apply plan.tfplan
terraform apply -auto-approve

# 销毁
terraform destroy
terraform destroy -auto-approve

# 查看状态
terraform show
terraform state list
terraform state show resource_type.name

# 输出
terraform output
terraform output -json

HCL 语法

Provider 配置

# providers.tf
terraform {
  required_version = ">= 1.0"
  
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
  
  backend "s3" {
    bucket = "my-terraform-state"
    key    = "prod/terraform.tfstate"
    region = "us-east-1"
  }
}

provider "aws" {
  region = var.aws_region
  
  default_tags {
    tags = {
      Environment = var.environment
      ManagedBy   = "Terraform"
    }
  }
}

变量定义

# variables.tf
variable "aws_region" {
  description = "AWS region"
  type        = string
  default     = "us-east-1"
}

variable "instance_type" {
  description = "EC2 instance type"
  type        = string
  default     = "t3.micro"
}

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

variable "tags" {
  description = "Resource tags"
  type        = map(string)
  default     = {}
}

variable "subnets" {
  description = "Subnet configuration"
  type = list(object({
    cidr_block = string
    az         = string
  }))
}

资源定义

# main.tf
resource "aws_vpc" "main" {
  cidr_block           = "10.0.0.0/16"
  enable_dns_hostnames = true
  
  tags = {
    Name = "${var.environment}-vpc"
  }
}

resource "aws_subnet" "public" {
  count             = length(var.subnets)
  vpc_id            = aws_vpc.main.id
  cidr_block        = var.subnets[count.index].cidr_block
  availability_zone = var.subnets[count.index].az
  
  tags = {
    Name = "${var.environment}-public-${count.index + 1}"
  }
}

resource "aws_instance" "web" {
  ami           = data.aws_ami.ubuntu.id
  instance_type = var.instance_type
  subnet_id     = aws_subnet.public[0].id
  
  tags = merge(var.tags, {
    Name = "${var.environment}-web"
  })
}