この記事は、Terraform Advent Calendar 2021 23日目のエントリです。
はじめに
Terraformは名前だけ知ってました。なお、Windows端末で立てていきます。
まとめ
Terraformでガワを作って、Ansibleで中身整えるで良さそう。
あと勉強しながらこの記事を書いていましたが、ながら執筆って良いかもしれない。
こういうログのほうが記事に良いなって思うたびにやり直すので。
AzureでVM作成と比較した
なるほど、Terraformってほぼ同じ感じで使いまわせるんだなぁと思いました。
まずは用語や雰囲気をおさえた
まずは、社内でお勧めされていた以下の動画を視聴し、用語と雰囲気を知りました。
https://www.youtube.com/watch?v=h1MDCp7blmg
次にWindows端末で環境構築した
1. Pathが通ってるフォルダ（例えばc:\Windows直下）に、terraform.exeを置きます。
https://www.terraform.io/downloads
2. AWS CLIをインストールします。
https://docs.aws.amazon.com/ja_jp/cli/latest/userguide/install-cliv2-windows.html
公式ドキュメントだと、Chocolateyを利用する方法のようです（本記事では未実施）
https://learn.hashicorp.com/tutorials/terraform/install-cli?in=terraform/aws-get-started
コマンドを打った
まずはバージョンの確認とhelpを見てみます。
C:\Users\ユーザ名>terraform version Terraform v1.1.0 on windows_amd64 C:\Users\ユーザ名>aws --version aws-cli/2.4.6 Python/3.8.8 Windows/10 exe/AMD64 prompt/off C:\Users\ユーザ名>terraform -help Usage: terraform [global options] <subcommand> [args] The available commands for execution are listed below. The primary workflow commands are given first, followed by less common or more advanced commands. Main commands: init Prepare your working directory for other commands validate Check whether the configuration is valid plan Show changes required by the current configuration apply Create or update infrastructure destroy Destroy previously-created infrastructure All other commands: console Try Terraform expressions at an interactive command prompt fmt Reformat your configuration in the standard style force-unlock Release a stuck lock on the current workspace get Install or upgrade remote Terraform modules (略) Global options (use these before the subcommand, if any): -chdir=DIR Switch to a different working directory before executing the given subcommand. -help Show this help output, or the help for a specified subcommand. -version An alias for the "version" subcommand.
いろいろ機能があるんだなぁと思いつつ、Main commandsを実行するため、各種ファイルを作成していきます。
- 認証情報の作成
「C:\Users\ユーザ名\」配下に「.aws」フォルダを作り、「credentials」ファイルを作成します。
メモ帳で作成、改行コードもCRLFで大丈夫です。
しばらくCMDでコマンド打ってなかったので、lsでもviでもcatでもない、なんだっけと調べるほうが時間かかりました。
[default] aws_access_key_id=AKI*********** aws_secret_access_key=***********
- 学習用ディレクトリの作成
適当な名前のディレクトリを作って、移動しましょう。
C:\Users\ユーザ名>mkdir study_terraform C:\Users\ユーザ名>cd study_terraform
- main.tfの作成
main.tfファイルに、作成するインスタンスのリソース情報を記載します。
リソース情報はなるべく少なくし、デフォルト設定任せにしています。
AMIは好きなものを選んでください。
main.tfも、認証情報同様メモ帳などで作って大丈夫です。
provider "aws" { region = "ap-northeast-1" } resource "aws_instance" "mito-ec2" { ami = "ami-********" instance_type = "t2.micro" key_name = "キー名" associate_public_ip_address = "true" tags = { Name = "mito-ec2" } } output "ec2-ip"{ value = aws_instance.mito-ec2.public_ip }
- terraform initの実行
ワークスペースの初期化や、実行に必要なバイナリファイルをダウンロードします。
C:\Users\ユーザ名\study_terraform>terraform init Initializing the backend... Initializing provider plugins... - Reusing previous version of hashicorp/aws from the dependency lock file - Using previously-installed hashicorp/aws v3.69.0 Terraform has been successfully initialized! You may now begin working with Terraform. Try running "terraform plan" to see any changes that are required for your infrastructure. All Terraform commands should now work. If you ever set or change modules or backend configuration for Terraform, rerun this command to reinitialize your working directory. If you forget, other commands will detect it and remind you to do so if necessary. C:\Users\ユーザ名\study_terraform> C:\Users\ユーザ名\study_terraform>dir Volume in drive C is Windows Volume Serial Number is **** Directory of C:\Users\ユーザ名\study_terraform 2021/12/22 23:07 <DIR> . 2021/12/22 23:07 <DIR> .. 2021/12/22 23:07 <DIR> .terraform 2021/12/22 23:07 1,077 .terraform.lock.hcl 2021/12/22 22:36 358 main.tf 2 File(s) 1,435 bytes 3 Dir(s) 53,891,817,472 bytes free C:\Users\ユーザ名\study_terraform>
- terraform validateの実行
構文チェックを行います。
C:\Users\ユーザ名\study_terraform>terraform validate Success! The configuration is valid. C:\Users\ユーザ名\study_terraform>
- terraform planの実行
作成されるリソースが確認できます。
なお、作成だけでなく、コードを更新した場合は既存環境との差分やリソースの変更なども確認できます。
C:\Users\ユーザ名\study_terraform>terraform plan Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols: + create Terraform will perform the following actions: # aws_instance.mito-ec2 will be created + resource "aws_instance" "mito-ec2" { + ami = "ami-********" + arn = (known after apply) + associate_public_ip_address = true + availability_zone = (known after apply) + cpu_core_count = (known after apply) + cpu_threads_per_core = (known after apply) + disable_api_termination = (known after apply) + ebs_optimized = (known after apply) + get_password_data = false + host_id = (known after apply) + id = (known after apply) + instance_initiated_shutdown_behavior = (known after apply) + instance_state = (known after apply) + instance_type = "t2.micro" + ipv6_address_count = (known after apply) + ipv6_addresses = (known after apply) + key_name = "キー名" + monitoring = (known after apply) + outpost_arn = (known after apply) + password_data = (known after apply) + placement_group = (known after apply) + placement_partition_number = (known after apply) + primary_network_interface_id = (known after apply) + private_dns = (known after apply) + private_ip = (known after apply) + public_dns = (known after apply) + public_ip = (known after apply) + secondary_private_ips = (known after apply) + security_groups = (known after apply) + source_dest_check = true + subnet_id = (known after apply) + tags = { + "Name" = "mito-ec2" } + tags_all = { + "Name" = "mito-ec2" } + tenancy = (known after apply) + user_data = (known after apply) + user_data_base64 = (known after apply) + vpc_security_group_ids = (known after apply) + capacity_reservation_specification { + capacity_reservation_preference = (known after apply) + capacity_reservation_target { + capacity_reservation_id = (known after apply) } } + ebs_block_device { + delete_on_termination = (known after apply) + device_name = (known after apply) + encrypted = (known after apply) + iops = (known after apply) + kms_key_id = (known after apply) + snapshot_id = (known after apply) + tags = (known after apply) + throughput = (known after apply) + volume_id = (known after apply) + volume_size = (known after apply) + volume_type = (known after apply) } + enclave_options { + enabled = (known after apply) } + ephemeral_block_device { + device_name = (known after apply) + no_device = (known after apply) + virtual_name = (known after apply) } + metadata_options { + http_endpoint = (known after apply) + http_put_response_hop_limit = (known after apply) + http_tokens = (known after apply) } + network_interface { + delete_on_termination = (known after apply) + device_index = (known after apply) + network_interface_id = (known after apply) } + root_block_device { + delete_on_termination = (known after apply) + device_name = (known after apply) + encrypted = (known after apply) + iops = (known after apply) + kms_key_id = (known after apply) + tags = (known after apply) + throughput = (known after apply) + volume_id = (known after apply) + volume_size = (known after apply) + volume_type = (known after apply) } } Plan: 1 to add, 0 to change, 0 to destroy. Changes to Outputs: + ec2-ip = (known after apply) ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── Note: You didn't use the -out option to save this plan, so Terraform can't guarantee to take exactly these actions if you run "terraform apply" now. C:\Users\ユーザ名\study_terraform>
- terraform applyの実行
main.tfで設定したリソースを一気に作ります。
C:\Users\ユーザ名\study_terraform>terraform apply Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols: + create Terraform will perform the following actions: # aws_instance.mito-ec2 will be created + resource "aws_instance" "mito-ec2" { + ami = "ami-********" + arn = (known after apply) + associate_public_ip_address = true + availability_zone = (known after apply) + cpu_core_count = (known after apply) + cpu_threads_per_core = (known after apply) + disable_api_termination = (known after apply) + ebs_optimized = (known after apply) + get_password_data = false + host_id = (known after apply) + id = (known after apply) + instance_initiated_shutdown_behavior = (known after apply) + instance_state = (known after apply) + instance_type = "t2.micro" + ipv6_address_count = (known after apply) + ipv6_addresses = (known after apply) + key_name = "キー名" + monitoring = (known after apply) + outpost_arn = (known after apply) + password_data = (known after apply) + placement_group = (known after apply) + placement_partition_number = (known after apply) + primary_network_interface_id = (known after apply) + private_dns = (known after apply) + private_ip = (known after apply) + public_dns = (known after apply) + public_ip = (known after apply) + secondary_private_ips = (known after apply) + security_groups = (known after apply) + source_dest_check = true + subnet_id = (known after apply) + tags = { + "Name" = "mito-ec2" } + tags_all = { + "Name" = "mito-ec2" } (略) } Plan: 1 to add, 0 to change, 0 to destroy. Changes to Outputs: + ec2-ip = (known after apply) Do you want to perform these actions? Terraform will perform the actions described above. Only 'yes' will be accepted to approve. Enter a value: yes aws_instance.mito-ec2: Creating... aws_instance.mito-ec2: Still creating... [10s elapsed] aws_instance.mito-ec2: Still creating... [20s elapsed] aws_instance.mito-ec2: Still creating... [30s elapsed] aws_instance.mito-ec2: Creation complete after 36s [id=i-02abe6f0e4497ed52] Apply complete! Resources: 1 added, 0 changed, 0 destroyed. Outputs: ec2-ip = "52.199.5.247" C:\Users\ユーザ名\study_terraform> C:\Users\ユーザ名\study_terraform>dir Volume in drive C is Windows Volume Serial Number is **** Directory of C:\Users\ユーザ名\study_terraform 2021/12/22 23:15 <DIR> . 2021/12/22 23:15 <DIR> .. 2021/12/22 23:07 <DIR> .terraform 2021/12/22 23:07 1,077 .terraform.lock.hcl 2021/12/22 22:36 358 main.tf 2021/12/22 23:15 3,943 terraform.tfstate 3 File(s) 5,378 bytes 3 Dir(s) 53,894,037,504 bytes free C:\Users\ユーザ名\study_terraform>
ステータスチェック中であり、すぐ起動が完了するわけではないよね。
起動まで待つ仕組みはあるでしょう。
また、tfstateファイルに作成したリソース情報が記載されます。
{ "version": 4, "terraform_version": "1.1.0", "serial": 2, "lineage": "*********", "outputs": { "ec2-ip": { "value": "52.199.5.247", "type": "string" } }, "resources": [ { "mode": "managed", "type": "aws_instance", "name": "mito-ec2", "provider": "provider[\"registry.terraform.io/hashicorp/aws\"]", "instances": [ { "schema_version": 1, "attributes": { "ami": "ami-******", (略) } ] } ] }
- terraform destroyの実行
作成した環境を一気に壊します！
C:\Users\ユーザ名\study_terraform>terraform destroy aws_instance.mito-ec2: Refreshing state... [id=i-02abe6f0e4497ed52] Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols: - destroy Terraform will perform the following actions: # aws_instance.mito-ec2 will be destroyed - resource "aws_instance" "mito-ec2" { - ami = "ami-********" -> null - arn = "arn:aws:ec2:ap-northeast-1:*******:instance/i-02abe6f0e4497ed52" -> null - associate_public_ip_address = true -> null - availability_zone = "ap-northeast-1a" -> null - cpu_core_count = 1 -> null - cpu_threads_per_core = 1 -> null (略) - tags = { - "Name" = "mito-ec2" } -> null - tags_all = { - "Name" = "mito-ec2" } -> null (略) } Plan: 0 to add, 0 to change, 1 to destroy. Changes to Outputs: - ec2-ip = "52.199.5.247" -> null Do you really want to destroy all resources? Terraform will destroy all your managed infrastructure, as shown above. There is no undo. Only 'yes' will be accepted to confirm. Enter a value: yes aws_instance.mito-ec2: Destroying... [id=i-02abe6f0e4497ed52] aws_instance.mito-ec2: Still destroying... [id=i-02abe6f0e4497ed52, 10s elapsed] aws_instance.mito-ec2: Still destroying... [id=i-02abe6f0e4497ed52, 20s elapsed] (略) aws_instance.mito-ec2: Still destroying... [id=i-02abe6f0e4497ed52, 2m20s elapsed] aws_instance.mito-ec2: Destruction complete after 2m25s Destroy complete! Resources: 1 destroyed. C:\Users\キー名\study_terraform>
気持ちいい。。。
