前言
Terraform是一种开源基础设施及代码（IaC）的工具，可提供统一的CLI（命令行接口)工作流来治理数百个云服务，将云API编码为申明性的配置文件进行治理。
本文创立一个治理AWS Lightsail实例的例子来入门Terraform的应用。
装置Terraform CLI
要应用Terramform，首先要在本地零碎装置Terraform命令行工具。HashiCorp提供了预编译好的二进制散发包，能够通过(https://www.terraform.com/dow...) 间接下载相应平台的二进制包，解压后放到相应的执行门路。也能够通过一些软件包管理工具装置，例如在Linux/OS X上通过LinuxBrew/HomeBrew进行装置，在Windows上通过Chocolatey进行装置。
这里咱们示例在Linux上是应用LinuxBrew进行装置
> brew install terraform装置实现后，能够查看其版本
❯ terraform -versionTerraform v1.0.11on linux_amd64应用-help查看其可用命令，装置胜利后，咱们就能够应用Terraform来创立相应的基础设施我的项目了。
AWS账号筹备
本文将通过创立一个治理AWS Lightsial实例的我的项目来尝试Terraform，因而须要一个AWS账号，以及在本地环境装置和配置好AWS CLI工具的拜访凭据。
装置和配置AWS CLI，请参考其文档 (https://docs.aws.amazon.com/c...) 。 配置实现之后，能够在本地命令行终端拜访相应的AWS资源。
创立并初始化Terraform我的项目
Terraform在本地通过文件夹来治理一个基础设施我的项目的申明性代码，例如咱们在本地创立一个文件夹
> mkdir mylightsail> cd mylightsail/进入文件夹后，创立一个以 .tf 作为后缀的文件，例如 main.tf
> touch main.tf而后应用编辑器关上文件进行编辑，写入以下代码块
terraform { required_providers { aws = { source = "hashicorp/aws" version = "~> 3.65" } }}# Configure the AWS Providerprovider "aws" { region = "ap-southeast-1"}其中 terraform/required_providers 块定义了该我的项目须要的 Provider，Terraform是通过不同的Provider来治理相应的基础设施资源的，可到 (https://registry.terraform.io) 来查找须要的Providers，例如GCP，Azure以及阿里云等的Providers。这里因为咱们要治理的资源是AWS Lightsail实例，所以应用了Hashicorp官网提供的 hashicorp/aws 。
provider "aws" 局部配置了该Provider的一些可选项，例如这里配置了区域为 ap-southeast-1 ，因而请确保下面配置的AWS拜访凭据可能操作该区域的资源。
也就是这里咱们定义了咱们须要应用的Provider及其相应的选项配置，接下来咱们须要应用 terraform init 命令来初始化我的项目
> terraform initInitializing provider plugins......Terraform has been successfully initialized!初始化将会从 (https://registry.terraform.io/) 下载相应的Provider插件到 .terramorm/providers/ 目录，供接下來的命令应用。
同时，会生成一个 .terraform.lock.hcl 的文件来记录应用的具体Provider版本，其性能相似于NPM的package-lock文件，可将其提交到代码版本治理仓库，其余合作的成员就能够放弃应用雷同的插件版本。
创立基础设施资源
实现我的项目的初始化之后，咱们就能够编写须要创立的资源申明性配置，能够间接将相应的配置写入 main.tf 文件，也能够另外创立新的以 .tf 作为后缀的文件，这里咱们创立一个新的名为 resources.tf 的文件，并写入咱们须要的资源的定义
## LightSail Resourcesresource "aws_lightsail_static_ip" "Example-sig-ip" { name = "Example-EIP"}resource "aws_lightsail_instance" "Example-sig" { name = "Example-Sig" availability_zone = "ap-southeast-1c" blueprint_id = "ubuntu_20_04" bundle_id = "nano_2_0" key_pair_name = "LightsailDefaultKeyPair" tags = { Example = "" }}resource "aws_lightsail_static_ip_attachment" "Example-sig-ip-attache" { static_ip_name = aws_lightsail_static_ip.Example-sig-ip.id instance_name = aws_lightsail_instance.Example-sig.id}resource "aws_lightsail_instance_public_ports" "Example-sig-public-ports" { instance_name = aws_lightsail_instance.Example-sig.name port_info { protocol = "tcp" from_port = 0 to_port = 65535 cidrs = [ "0.0.0.0/0" ] } port_info { protocol = "udp" from_port = 0 to_port = 65535 cidrs = [ "0.0.0.0/0" ] }}定义资源的格局为 resource "[provider_resource _type]" "resource_name"，第一个参数为相应Provider反对的资源类型名称，第二个参数为本人定义的资源名称（可用于其余资源援用）。例如，咱们首先定义了一个Lightsail的动态IP资源，其中参数 name 指定了AWS资源的名称。
下面的定义中，咱们申明了以下资源
- 一个Lightsail动态IP地址
- 一个Lightsail计算实例，并绑定名为
LightsailDefaultKeyPair的SSH密钥 - 动态IP地址和计算实例的绑定
- 实例的凋谢的网络端口组（相似于AWS EC2实例的平安组定义）
保留文件之后，咱们能够应用 terraform fmt 命令来格式化文件格式，以及 terraform validate 来查看是否有语法错误。
定义好咱们想要的资源之后，咱们先通过命令 terraform plan 命令来执行打算，查看具体的执行更改（plan不会实际操作相应的资源）
❯ terraform plan Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols: + createTerraform will perform the following actions: # aws_lightsail_instance.Example-sig will be created + resource "aws_lightsail_instance" "Example-sig" { + arn = (known after apply) + availability_zone = "ap-southeast-1c" + blueprint_id = "ubuntu_20_04" + bundle_id = "nano_2_0" + cpu_count = (known after apply) + created_at = (known after apply) + id = (known after apply) + ipv6_address = (known after apply) + ipv6_addresses = (known after apply) + is_static_ip = (known after apply) + key_pair_name = "LightsailDefaultKeyPair" + name = "Example-Sig" + private_ip_address = (known after apply) + public_ip_address = (known after apply) + ram_size = (known after apply) + tags = { + "Example" = "" } + tags_all = { + "Example" = (known after apply) } + username = (known after apply) } # aws_lightsail_instance_public_ports.Example-sig-public-ports will be created + resource "aws_lightsail_instance_public_ports" "Example-sig-public-ports" { + id = (known after apply) + instance_name = "Example-Sig" + port_info { + cidrs = [ + "0.0.0.0/0", ] + from_port = 0 + protocol = "tcp" + to_port = 65535 } + port_info { + cidrs = [ + "0.0.0.0/0", ] + from_port = 0 + protocol = "udp" + to_port = 65535 } } # aws_lightsail_static_ip.Example-sig-ip will be created + resource "aws_lightsail_static_ip" "Example-sig-ip" { + arn = (known after apply) + id = (known after apply) + ip_address = (known after apply) + name = "Example-EIP" + support_code = (known after apply) } # aws_lightsail_static_ip_attachment.Example-sig-ip-attache will be created + resource "aws_lightsail_static_ip_attachment" "Example-sig-ip-attache" { + id = (known after apply) + instance_name = (known after apply) + ip_address = (known after apply) + static_ip_name = (known after apply) }Plan: 4 to add, 0 to change, 0 to destroy.+示意将要减少的资源，(know after apply)的意思是要在具体只想（apply）之后，AWS依据定义创立相应资源之后才会返回的具体值。接下来就能够应用 terraform apply 来具体执行操作了，执行胜利之后，会生成 .terraform/terraform.state 文件来记录执行后的资源状态，也能够通过命令 terraform show 命令来查看
❯ terraform show# aws_lightsail_instance.Example-sig:resource "aws_lightsail_instance" "Example-sig" { arn = "arn:aws:lightsail:ap-southeast-1:090767794770:Instance/21cb0ea5-e814-4307-8606-01348d98be15" availability_zone = "ap-southeast-1c" blueprint_id = "ubuntu_20_04" bundle_id = "nano_2_0" cpu_count = 1 created_at = "2021-11-08T05:49:05Z" id = "Example-Sig" ipv6_address = "2406:da18:8ae:4b02:1f2:4ff1:daa1:6a8c" ipv6_addresses = [ "2406:da18:8ae:4b02:1f2:4ff1:daa1:6a8c", ] is_static_ip = true key_pair_name = "LightsailDefaultKeyPair" name = "Example-Sig" private_ip_address = "172.26.45.249" public_ip_address = "54.220.33.133" ram_size = 0.5 tags = { "Example" = "" } tags_all = { "Example" = "" } username = "ubuntu"}# aws_lightsail_instance_public_ports.Example-sig-public-ports:resource "aws_lightsail_instance_public_ports" "Example-sig-public-ports" { id = "Example-Sig-987241840" instance_name = "Example-Sig" port_info { cidrs = [ "0.0.0.0/0", ] from_port = 0 protocol = "tcp" to_port = 65535 } port_info { cidrs = [ "0.0.0.0/0", ] from_port = 0 protocol = "udp" to_port = 65535 }}# aws_lightsail_static_ip.Example-sig-ip:resource "aws_lightsail_static_ip" "Example-sig-ip" { arn = "arn:aws:lightsail:ap-southeast-1:090767794770:StaticIp/3f0298e0-efeb-4429-9574-156fef12a48f" id = "Example-EIP" ip_address = "54.220.33.133" name = "Example-EIP" support_code = "313963776615/54.220.33.133"}# aws_lightsail_static_ip_attachment.Example-sig-ip-attache:resource "aws_lightsail_static_ip_attachment" "exmaple-sig-ip-attache" { id = "Example-EIP" instance_name = "Example-Sig" ip_address = "54.220.33.133" static_ip_name = "Example-EIP"}之后咱们就能够通过更新资源定义文件，而后执行 plan & apply 来更新云上的资源了，如果资源不须要了，咱们也能够通过 terraform destroy 一条命令来销毁所有资源。
总结
本文以治理简略的AWS Lightsail资源为例，展现了如何应用Terraform来治理云上的资源。通过一申明性的代码来定义咱们须要的资源，同时资源定义代码能够通过版本管理工具进行版本化治理，进一步实现IaC的工作形式。
这么咱们应用的是Terraform的本地执行模式，除了在本地执行之外，Terraform还提供了执行后端（Backend）的性能，就能够将执行放到云上的一些执行环境，资源状态的治理也将会保护在Backend端，不便实现CI/CD Pipeline，以及GitOps的形式。其中Hashicorp的Terraform Cloud就是一个Backend。下一篇文章将示例将该我的项目放到Terraform Cloud下来执行。