【サンプル付き】Terraform環境をDockerを使って一撃で整える

.
├── .gitignore
├── README.md
├── dockerfiles
│   ├── Dockerfile_terraform
│   └── docker-compose.yml
└── mountpoint
    ├── .aws
    │   ├── config
    │   └── credentials
    └── sample
        └── main.tf

# clone作成
$ git clone https://github.com/hgssnk/terraform-and-docker.git

# AWS CLI用のディレクトリ作成
mkdir terraform-and-docker/mountpoint/.aws

[default]
region = us-west-2
output = json

[default]
aws_access_key_id=*********************
aws_secret_access_key=*************************

# 移動
$ cd terraform-and-docker/dockerfiles

# コンテナ生成
$ docker-compose up -d --build
Building terraform
[+] Building 3.3s (7/7) FINISHED
 => [internal] load build definition from Dockerfile_terraform             0.0s
 => => transferring dockerfile: 395B                                       0.0s
 => [internal] load .dockerignore                                          0.0s
 => => transferring context: 2B                                            0.0s
 => [internal] load metadata for docker.io/hashicorp/terraform:1.3.1       3.2s
 => [auth] hashicorp/terraform:pull token for registry-1.docker.io         0.0s
 => [1/2] FROM docker.io/hashicorp/terraform:1.3.1@sha256:160c8cc975c35e9  0.0s
 => CACHED [2/2] WORKDIR /tmp/terraform                                    0.0s
 => exporting to image                                                     0.0s
 => => exporting layers                                                    0.0s
 => => writing image sha256:364f3a4fc6969058c8c8343abd88fc2f19b6ecfe2a01b  0.0s
 => => naming to docker.io/library/dockerfiles_terraform                   0.0s
Recreating terraform ... done

# コンテナ確認
$ docker ps
CONTAINER ID   IMAGE                   COMMAND                  CREATED          STATUS          PORTS     NAMES
90a93ac58aff   dockerfiles_terraform   "/bin/sh -c 'while :…"   53 seconds ago   Up 53 seconds             terraform

# sampleファイルをinit
# AMI IDが変わっていて、実行できないことがあるかもです(リージョンを変更した場合など)
$ docker exec -it terraform /bin/terraform -chdir=sample/ init

Initializing the backend...

Initializing provider plugins...
- Finding latest version of hashicorp/aws...
- Installing hashicorp/aws v4.33.0...
- Installed hashicorp/aws v4.33.0 (signed by HashiCorp)

Terraform has created a lock file .terraform.lock.hcl to record the provider
selections it made above. Include this file in your version control repository
so that Terraform can guarantee to make the same selections by default when
you run "terraform init" in the future.

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.



# plan実行
$ docker exec -it terraform /bin/terraform -chdir=sample/ 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.hoge will be created
  + resource "aws_instance" "hoge" {
      + ami                                  = "ami-08e2d37b6a0129927"
      + arn                                  = (known after apply)
................................ 省略
Plan: 1 to add, 0 to change, 0 to destroy.

────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

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.



# apply実行
$ docker exec -it terraform /bin/terraform -chdir=sample/ apply

# aws_instance.hoge:
resource "aws_instance" "hoge" {
    ami                                  = "ami-08e2d37b6a0129927"
    arn                                  = "arn:aws:ec2:us-west-2:293157066816:instance/i-0f5ea121b38a86941"
................................ 省略

# destroyを実行
$ docker exec -it terraform /bin/terraform -chdir=sample/ destroy

aws_instance.hoge: Refreshing state... [id=i-0f5ea121b38a86941]

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  - destroy

............................... 省略

Plan: 0 to add, 0 to change, 1 to destroy.

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.hoge: Destroying... [id=i-0f5ea121b38a86941]
aws_instance.hoge: Still destroying... [id=i-0f5ea121b38a86941, 10s elapsed]
aws_instance.hoge: Still destroying... [id=i-0f5ea121b38a86941, 20s elapsed]
aws_instance.hoge: Still destroying... [id=i-0f5ea121b38a86941, 30s elapsed]
aws_instance.hoge: Still destroying... [id=i-0f5ea121b38a86941, 40s elapsed]
aws_instance.hoge: Destruction complete after 41s

Destroy complete! Resources: 1 destroyed.

# 起動中のコンテナ確認
$ docker ps
CONTAINER ID   IMAGE                   COMMAND                  CREATED         STATUS         PORTS     NAMES
0a2a94056d3d   dockerfiles_terraform   "/bin/sh -c 'while :…"   2 seconds ago   Up 2 seconds             terraform

# terraformコンテナを廃棄
$ docker rm -f terraform
terraform

# 廃棄確認
$ docker ps -a
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

# 複数のコンテナを全て一気に廃棄する場合は以下（Bashの場合）
$ docker rm -f $(docker ps -qa)
aab12b441eb0