cloudformation(SAM)でapi-gateway,lambda を生成する

# 作業エリア作成
$ mkdir test
$ cd test

# python 3.11.5 インストール＆設定
$ pyenv install 3.11.5
$ pyenv local 3.11.5

# sam インストール(python3.11.5 に sam がパッケージとしてインストールされるので注意。python3.11.5以外は使えない)
$ pip install aws-sam-cli
# sam バージョン確認
$ sam --version
SAM CLI, version 1.97.0

# sam アプリベース作成
$ sam init --runtime=python3.11
Which template source would you like to use?
        1 - AWS Quick Start Templates
        2 - Custom Template Location
Choice: 1

Choose an AWS Quick Start application template
        1 - Hello World Example
        2 - Hello World Example With Powertools for AWS Lambda
        3 - Infrastructure event management
        4 - Multi-step workflow
        5 - Lambda EFS example
        6 - Serverless Connector Hello World Example
        7 - Multi-step workflow with Connectors
Template: 1

Based on your selections, the only Package type available is Zip.
We will proceed to selecting the Package type as Zip.

Based on your selections, the only dependency manager available is pip.
We will proceed copying the template using pip.

Would you like to enable X-Ray tracing on the function(s) in your application?  [y/N]: # 追加料金が必要らしいのでやめ

Would you like to enable monitoring using CloudWatch Application Insights?
For more info, please view https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch-application-insights.html [y/N]: # 追加料金が必要らしいのでやめ

Project name [sam-app]: apitest-app

Cloning from https://github.com/aws/aws-sam-cli-app-templates (process may take a moment)

    -----------------------
    Generating application:
    -----------------------
    Name: apitest-app
    Runtime: python3.11
    Architectures: x86_64
    Dependency Manager: pip
    Application Template: hello-world
    Output Directory: .
    Configuration file: apitest-app/samconfig.toml

    Next steps can be found in the README file at apitest-app/README.md


Commands you can use next
=========================
[*] Create pipeline: cd apitest-app && sam pipeline init --bootstrap
[*] Validate SAM template: cd apitest-app && sam validate
[*] Test Function in the Cloud: cd apitest-app && sam sync --stack-name {stack-name} --watch

$ tree
.
└── apitest-app
    ├── README.md
    ├── __init__.py
    ├── events
    │   └── event.json
    ├── hello_world
    │   ├── __init__.py
    │   ├── app.py
    │   └── requirements.txt
    ├── samconfig.toml
    ├── template.yaml
    └── tests
        ├── __init__.py
        ├── integration
        │   ├── __init__.py
        │   └── test_api_gateway.py
        ├── requirements.txt
        └── unit
            ├── __init__.py
            └── test_handler.py

6 directories, 14 files

$ cd apitest-app
# sam 実行
#  初回はdocker imageをダウンロードしてくるので遅い。。。
$ sam local start-api
Initializing the lambda functions containers.
Local image is out of date and will be updated to the latest runtime. To skip this, pass in the parameter --skip-pull-image
Building image..............................................................................................................................................................................................................................
Using local image: public.ecr.aws/lambda/python:3.11-rapid-x86_64.

Mounting /home/developer/test/apitest-app/hello_world as /var/task:ro,delegated, inside runtime container
Containers Initialization is done.
Mounting HelloWorldFunction at http://127.0.0.1:3000/hello [GET]
You can now browse to the above endpoints to invoke your functions. You do not need to restart/reload SAM CLI while working on your
functions, changes will be reflected instantly/automatically. If you used sam build before running local commands, you will need to re-run
sam build for the changes to be picked up. You only need to restart SAM CLI if you update your AWS SAM template
2023-11-06 14:00:33 WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on http://127.0.0.1:3000
2023-11-06 14:00:33 Press CTRL+C to quit

# 別ターミナルから以下を実施
$ curl http://127.0.0.1:3000/hello 
{"message": "hello world"}

$ cd apitest-app
# このディレクトリ配下は python 3.11.5 を使うことを明示(venv使うために必要)
$ pyenv local 3.11.5
$ git init
hint: Using 'master' as the name for the initial branch. This default branch name
hint: is subject to change. To configure the initial branch name to use in all
hint: of your new repositories, which will suppress this warning, call:
hint:
hint:   git config --global init.defaultBranch <name>
hint:
hint: Names commonly chosen instead of 'master' are 'main', 'trunk' and
hint: 'development'. The just-created branch can be renamed via this command:
hint:
hint:   git branch -m <name>
# 上記のようなヒント表示されるが無視しておくことにする。

# git 登録(.gitignore は sam が初期設定したものが生成済みである)
$ git add .
$ git status
On branch master
No commits yet
Changes to be committed:
  (use "git rm --cached <file>..." to unstage)
        new file:   .gitignore
        new file:   README.md
        new file:   __init__.py
        new file:   events/event.json
        new file:   hello_world/__init__.py
        new file:   hello_world/app.py
        new file:   hello_world/requirements.txt
        new file:   samconfig.toml
        new file:   template.yaml
        new file:   tests/__init__.py
        new file:   tests/integration/__init__.py
        new file:   tests/integration/test_api_gateway.py
        new file:   tests/requirements.txt
        new file:   tests/unit/__init__.py
        new file:   tests/unit/test_handler.py

$ git commit -m "first commit"

$ cd apitest-app
$ cp -r hello_world my_get_function

...
    return {
        "statusCode": 200,
        "body": json.dumps({
            "message": "get api",     # <-- ここ変更しただけ
            # "location": ip.text.replace("\n", "")
        }),
    }

# Resources 節に追加
Resources:
  # ↓ここから追加
  MyGetFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: my_get_function/
      Handler: app.lambda_handler
      Runtime: python3.11
      Architectures:
        - x86_64
      Events:
        MyGet:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /myget
            Method: get
  # ↑まで追加
  ...
  # 最下部にある Outputs 節にも追加したならしていい。ログが出力されるだけなので追加しなくてもいい
  Outputs:
    # ↓ここから追加
    MyGetApi:
      Description: "API Gateway endpoint URL for Prod stage for my get function"
      Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/myget/"
    MyGetFunction:
      Description: "My Get Lambda Function ARN"
      Value: !GetAtt MyGetFunction.Arn
    MyGetFunctionIamRole:
      Description: "Implicit IAM Role created for My Get function"
      Value: !GetAtt MyGetFunctionRole.Arn
    # ↑まで追加

# api スタート
$ sam local start-api

# 別ターミナルから以下を実施
$ curl http://127.0.0.1:3000/myget
{"message": "get api"}

diff --git a/template.yaml b/template.yaml
index a216784..692648d 100644
--- a/template.yaml
+++ b/template.yaml
@@ -26,6 +26,21 @@ Resources:
             Path: /hello
             Method: get

+  MyGetFunction:
+    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
+    Properties:
+      CodeUri: my_get_function/
+      Handler: app.lambda_handler
+      Runtime: python3.11
+      Architectures:
+        - x86_64
+      Events:
+        MyGet:
+          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
+          Properties:
+            Path: /myget
+            Method: get
+
 Outputs:
   # ServerlessRestApi is an implicit API created out of Events key under Serverless::Function
   # Find out more about other implicit resources you can reference within SAM
@@ -39,3 +54,14 @@ Outputs:
   HelloWorldFunctionIamRole:
     Description: "Implicit IAM Role created for Hello World function"
     Value: !GetAtt HelloWorldFunctionRole.Arn
+
+  MyGetApi:
+    Description: "API Gateway endpoint URL for Prod stage for my get function"
+    Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/myget/"
+  MyGetFunction:
+    Description: "My Get Lambda Function ARN"
+    Value: !GetAtt MyGetFunction.Arn
+  MyGetFunctionIamRole:
+    Description: "Implicit IAM Role created for My Get function"
+    Value: !GetAtt MyGetFunctionRole.Arn
+

$ git add .
$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        new file:   my_get_function/__init__.py
        new file:   my_get_function/app.py
        new file:   my_get_function/requirements.txt
        modified:   template.yaml
$ git commit -m "add GET method api(myget)"

$ cd apitest-app
$ cp -r hello_world my_post_function

...
    return {
        "statusCode": 200,
        "body": json.dumps({
            "message": "post api",     # <-- ここ変更しただけ
            # "location": ip.text.replace("\n", "")
        }),
    }

# Resources 節に追加
Resources:
  # ↓ここから追加
  MyPostFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: my_post_function/
      Handler: app.lambda_handler
      Runtime: python3.11
      Architectures:
        - x86_64
      Events:
        MyGet:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /mypost
            Method: post
  # ↑まで追加
  ...
  # 最下部にある Outputs 節にも追加したならしていい。ログが出力されるだけなので追加しなくてもいい
  Outputs:
    # ↓ここから追加
    MyPostApi:
      Description: "API Gateway endpoint URL for Prod stage for my post function"
      Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/mypost/"
    MyGetFunction:
      Description: "My Post Lambda Function ARN"
      Value: !GetAtt MyPostFunction.Arn
    MyGetFunctionIamRole:
      Description: "Implicit IAM Role created for My Post function"
      Value: !GetAtt MyPostFunctionRole.Arn
    # ↑まで追加

# api スタート
$ sam local start-api

# 別ターミナルから以下を実施
$ curl -X POST http://127.0.0.1:3000/mypost
{"message": "post api"}

$ git add .
$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        new file:   my_get_function/__init__.py
        new file:   my_get_function/app.py
        new file:   my_get_function/requirements.txt
        modified:   template.yaml
$ git commit -m "add POST method api(mypost)"

diff --git a/template.yaml b/template.yaml
index 1b1c5ec..617555e 100644
--- a/template.yaml
+++ b/template.yaml
@@ -41,6 +41,21 @@ Resources:
             Path: /myget
             Method: get

+  MyPostFunction:
+    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
+    Properties:
+      CodeUri: my_post_function/
+      Handler: app.lambda_handler
+      Runtime: python3.11
+      Architectures:
+        - x86_64
+      Events:
+        MyGet:
+          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
+          Properties:
+            Path: /mypost
+            Method: post
+
 Outputs:
   # ServerlessRestApi is an implicit API created out of Events key under Serverless::Function
   # Find out more about other implicit resources you can reference within SAM
@@ -65,3 +80,12 @@ Outputs:
     Description: "Implicit IAM Role created for My Get function"
     Value: !GetAtt MyGetFunctionRole.Arn

+  MyPostApi:
+    Description: "API Gateway endpoint URL for Prod stage for my post function"
+    Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/mypost/"
+  MyPostFunction:
+    Description: "My Post Lambda Function ARN"
+    Value: !GetAtt MyPostFunction.Arn
+  MyPostFunctionIamRole:
+    Description: "Implicit IAM Role created for My Post function"
+    Value: !GetAtt MyPostFunctionRole.Arn

$ git add .
$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        new file:   my_post_function/__init__.py
        new file:   my_post_function/app.py
        new file:   my_post_function/requirements.txt
        modified:   template.yaml
$ git commit -m "add POST method api(mypost)"

$ cd apitest-app
$ rm -rf hello_world

diff --git a/template.yaml b/template.yaml
index 617555e..b76360f 100644
--- a/template.yaml
+++ b/template.yaml
@@ -11,21 +11,6 @@ Globals:
     Timeout: 3

 Resources:
-  HelloWorldFunction:
-    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
-    Properties:
-      CodeUri: hello_world/
-      Handler: app.lambda_handler
-      Runtime: python3.11
-      Architectures:
-        - x86_64
-      Events:
-        HelloWorld:
-          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
-          Properties:
-            Path: /hello
-            Method: get
-
   MyGetFunction:
     Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
     Properties:
     
 Outputs:
  # ServerlessRestApi is an implicit API created out of Events key under Serverless::Function
  # Find out more about other implicit resources you can reference within SAM
  # https://github.com/awslabs/serverless-application-model/blob/master/docs/internals/generated_resources.rst#api
-  HelloWorldApi:
-    Description: "API Gateway endpoint URL for Prod stage for Hello World function"
-    Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/hello/"
-  HelloWorldFunction:
-    Description: "Hello World Lambda Function ARN"
-    Value: !GetAtt HelloWorldFunction.Arn
-  HelloWorldFunctionIamRole:
-    Description: "Implicit IAM Role created for Hello World function"
-    Value: !GetAtt HelloWorldFunctionRole.Arn
     

$ git add .
$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        deleted:    hello_world/__init__.py
        deleted:    hello_world/app.py
        deleted:    hello_world/requirements.txt
        modified:   template.yaml
$ git commit -m "remove hello_world api"

$ cd apitest-app
$ mkdir client

<!doctype html>
<html lang="en">
  <head>
    <!-- Required meta tags -->
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">

    <!-- Bootstrap CSS -->
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
    <title>Local</title>
  </head>
  <body>
    <h1>Local</h1>
    <button type="button" class="btn btn-primary" onclick="GetSimpleRequest()">GET単純リクエスト</button>
    <button type="button" class="btn btn-primary" onclick="GetNonSimpleRequest()">GET非単純リクエスト</button>
    <br>
    <button type="button" class="btn btn-warning" onclick="PostSimpleRequest()">POST単純リクエスト</button>
    <button type="button" class="btn btn-warning" onclick="PostNonSimpleRequest()">POST非単純リクエスト</button>

    <script>
    // GET 単純リクエスト
    function GetSimpleRequest() {
        axios({
            method: 'get',
            url: 'http://127.0.0.1:3000/myget',
            headers: {
                'Content-Type': 'text/plain'
            },
        })
        .then(function (response) {
           console.log(response);
        })
        .catch(function (error) {
           console.log(error);
        });
     }
    // GET 非単純リクエスト
    function GetNonSimpleRequest() {
        axios({
            method: 'get',
            url: 'http://127.0.0.1:3000/myget',
            headers: {
                'Content-Type': 'application/json'
            },
            data: {
                message: 'Hello, world!'
            }
        })
        .then(function (response) {
            console.log(response);
        })
        .catch(function (error) {
            console.log(error);
        });
     }

    // POST 単純リクエスト
    function PostSimpleRequest() {
        axios({
            method: 'post',
            url: 'http://127.0.0.1:3000/mypost',
            headers: {
                'Content-Type': 'text/plain'
            },
            data: 'Hello, world!'
        })
        .then(function (response) {
            console.log(response);
        })
        .catch(function (error) {
            console.log(error);
        });
         // alert("Simple");
     }
    // POST 非単純リクエスト
    function PostNonSimpleRequest() {
        axios({
            method: 'post',
            url: 'http://127.0.0.1:3000/mypost',
            headers: {
                'Content-Type': 'application/json'
            },
            data: {
                message: 'Hello, world!'
            }
        })
        .then(function (response) {
            console.log(response);
        })
        .catch(function (error) {
            console.log(error);
        });
         // alert("NonSimple");
     }
    </script>

    <!-- Optional JavaScript; choose one of the two! -->
    <script src="https://cdn.jsdelivr.net/npm/axios/dist/axios.min.js"></script>

    <!-- Option 1: Bootstrap Bundle with Popper -->
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.bundle.min.js" integrity="sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM" crossorigin="anonymous"></script>

    <!-- Option 2: Separate Popper and Bootstrap JS -->
    <script src="https://cdn.jsdelivr.net/npm/@popperjs/core@2.9.2/dist/umd/popper.min.js" integrity="sha384-IQsoLXl5PILFhosVNubq5LC7Qb9DXgDA9i+tQ8Zj3iwWAwPtgFTxbJ8NT4GN1R8p" crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.min.js" integrity="sha384-cVKIPhGWiC2Al4u+LWgxfKTRIcfu0JTxR+EQDz/bgldoEyl4H0zUF0QKbrJ0EcQF" crossorigin="anonymous"></script>
  </body>
</html>

$ google-chrome client/local.html

$ git add .
$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        new file:   client/local.html
$ git commit -m "add client/local.html"

Resources:
  MyGetFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: my_get_function/
      Handler: app.lambda_handler
      Runtime: python3.11
      Architectures:
        - x86_64
      Events:
        MyGet:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /myget
            Method: get
            RestApiId: # <--- ここに MyApi 参照追加
              Ref: MyApi

  MyPostFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: my_post_function/
      Handler: app.lambda_handler
      Runtime: python3.11
      Architectures:
        - x86_64
      Events:
        MyGet:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /mypost
            Method: post
            RestApiId: # <--- ここに MyApi 参照追加
              Ref: MyApi

  MyApi: # <-- ここ追加
    Type: AWS::Serverless::Api
    Properties:
      StageName: Prod
      Cors:
        AllowOrigin: "'*'"
        AllowMethods: "'OPTIONS,GET,POST'"
        AllowHeaders: "'Content-Type'"

    res = { # <-- レスポンスにCORS対応情報追記
        "statusCode": 200,
        "headers": {
            "Access-Control-Allow-Origin": "*",  # ここを適切なオリジンに設定
            "Access-Control-Allow-Methods": "GET,OPTIONS",  # 許可するメソッドを設定
            "Access-Control-Allow-Headers": "Content-Type"  # 許可するヘッダーを設定
        },
        "body": json.dumps({
            "message": "get api",
            # "location": ip.text.replace("\n", "")
        }),
    }
    return res

...
    res = { # <-- レスポンスにCORS対応情報追記
        "statusCode": 200,
        "headers": {
            "Access-Control-Allow-Origin": "*",  # ここを適切なオリジンに設定
            "Access-Control-Allow-Methods": "POST,OPTIONS",  # 許可するメソッドを設定
            "Access-Control-Allow-Headers": "Content-Type"  # 許可するヘッダーを設定
        },
        "body": json.dumps({
            "message": "post api",
            # "location": ip.text.replace("\n", "")
        }),
    }
    return res

$ sam local start-api

# 別ターミナルから以下を実施
$ google-chrome client/local.html

$ git add .
$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        modified:   my_get_function/app.py
        modified:   my_post_function/app.py
        modified:   template.yaml
$ git commit -m "add CORS"

$ mkdir -p my_layer/python

class DBInfo():
    def __init__(self):
        super().__init__()
        self.connections = {}
        self.connections['host'] = 'locahost'
        self.connections['port'] = 8081
        self.connections['dbname'] = 'dbname'
        self.connections['user'] = 'user'
        self.connections['password'] = 'password'

...
Resources:
  MyGetFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: my_get_function/
      Handler: app.lambda_handler
      Runtime: python3.11
      Architectures:
        - x86_64
      Events:
        MyGet:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /myget
            Method: get
            RestApiId:
              Ref: MyApi
      Layers: # <-- ここに layer 参照追加
        - !Ref MyLayer

  MyPostFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: my_post_function/
      Handler: app.lambda_handler
      Runtime: python3.11
      Architectures:
        - x86_64
      Events:
        MyGet:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /mypost
            Method: post
            RestApiId:
              Ref: MyApi
      Layers: # <-- ここに layer 参照追加
        - !Ref MyLayer

  MyLayer: # <-- ここに layer 設定追加
    Type: AWS::Serverless::LayerVersion
    Properties:
      LayerName: my_layer
      Description: My layer description
      ContentUri: my_layer/
      CompatibleRuntimes:
        - python3.11
    Metadata:
      BuildMethod: python3.11
...

from db_info import DBInfo # <--- layer にあるクラス参照追記
...
    dbinfo = DBInfo() # <--- layer にあるクラス生成

    res = {
        "statusCode": 200,
        "headers": {
            "Access-Control-Allow-Origin": "*",  # ここを適切なオリジンに設定
            "Access-Control-Allow-Methods": "GET,OPTIONS",  # 許可するメソッドを設定
            "Access-Control-Allow-Headers": "Content-Type"  # 許可するヘッダーを設定
        },
        "body": json.dumps({
            "message": "get api(host:{}/port:{}/)".format(dbinfo.connections['host'], dbinfo.connections['port']), # <--- db情報参照
            # "location": ip.text.replace("\n", "")
        }),
    }
    return res

from db_info import DBInfo # <--- layer にあるクラス参照追記
...
    dbinfo = DBInfo() # <--- layer にあるクラス生成

    res = {
        "statusCode": 200,
        "headers": {
            "Access-Control-Allow-Origin": "*",  # ここを適切なオリジンに設定
            "Access-Control-Allow-Methods": "POST,OPTIONS",  # 許可するメソッドを設定
            "Access-Control-Allow-Headers": "Content-Type"  # 許可するヘッダーを設定
        },
        "body": json.dumps({
            "message": "post api(host:{}/port:{}/)".format(dbinfo.connections['host'], dbinfo.connections['port']), # <--- db情報参照
            # "location": ip.text.replace("\n", "")
        }),
    }
    return res

# layer を参照するために build が必要（か、手動で各apiに配置する必要がある)
$ sam build
# 実行
$ sam local start-api
Initializing the lambda functions containers.
MyLayer is a local Layer in the template            <--- layer追加するとこのログが出力される

# 別ターミナルから以下を実施
$ google-chrome client/local.html

# sam build を実施すると直下に.aws-sam ディレクトリが生成されるので.gitignoreに追記しておく
$ emacs .gitingore
...
.aws-sam/  <-- 追記

# 登録
$ git add .
$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        modified:   .gitignore
        modified:   my_get_function/app.py
        new file:   my_layer/python/db_info.py
        modified:   my_post_function/app.py
        modified:   template.yaml
$ git commit -m "add layer"

$ sam deploy --guided --profile XXX

Configuring SAM deploy
======================

        Looking for config file [samconfig.toml] :  Found
        Reading default arguments  :  Success

        Setting default arguments for 'sam deploy'
        =========================================
        Stack Name [apitest-app]:
        AWS Region [ap-northeast-1]:
        ## デプロイが行われる前に、どのリソースがどのように変更されるかを表示し、ユーザーがそれらの変更を確認するかどうか
        #Shows you resources changes to be deployed and require a 'Y' to initiate deploy
        Confirm changes before deploy [Y/n]:
        ## SAM CLIがAWS Identity and Access Management (IAM) ロールを作成することを許可するかどうか
        #SAM needs permission to be able to create roles to connect to the resources in your template
        Allow SAM CLI IAM role creation [Y/n]:
        ## プロビジョニングされたリソースの状態を保持するかどうか
        ## 'y’を入力すると、操作が失敗した場合でも以前にプロビジョニングされたリソースの状態が保持される
        ## 'N’を入力すると（これがデフォルトです）、操作が失敗した場合にはロールバックが行われ、変更が元に戻される
        #Preserves the state of previously provisioned resources when an operation fails
        Disable rollback [y/N]:
        ## 認証を持っていないことを指摘し、それが問題ないかどうかを尋ねている
        ## 'y’を入力すると、認証なしでHelloWorldFunctionをデプロイすることを許可
        MyGetFunction has no authentication. Is this okay? [y/N]: y
        MyPostFunction has no authentication. Is this okay? [y/N]: y
        ## 保存確認
        Save arguments to configuration file [Y/n]:
        SAM configuration file [samconfig.toml]:
        SAM configuration environment [default]:

        Looking for resources needed for deployment:
        Creating the required resources...
        Successfully created! 

        Managed S3 bucket: aws-sam-cli-managed-default-samclisourcebucket-1eli41thgg4jk
        A different default S3 bucket can be set in samconfig.toml and auto resolution of buckets turned off by setting resolve_s3=False

        Parameter "stack_name=apitest-app" in [default.deploy.parameters] is defined as a global parameter [default.global.parameters].
        This parameter will be only saved under [default.global.parameters] in /home/developer/test/apitest-app/samconfig.toml.

        Saved arguments to config file
        Running 'sam deploy' for future deployments will use the parameters saved above.
        The above parameters can be changed by modifying samconfig.toml
        Learn more about samconfig.toml syntax at
        https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-config.html

        Uploading to apitest-app/d006400a8973740f15f568f9fd522821  547413 / 547413  (100.00%)
        Uploading to apitest-app/548c139a208e531d252a6f1827bd30e7  547414 / 547414  (100.00%)
        Uploading to apitest-app/a31e2576d4db1b6dcebe12cd4840c3ae  270 / 270  (100.00%)

        Deploying with following values
        ===============================
        Stack name                   : apitest-app
        Region                       : ap-northeast-1
        Confirm changeset            : True
        Disable rollback             : False
        Deployment s3 bucket         : aws-sam-cli-managed-default-samclisourcebucket-1eli41thgg4jk
        Capabilities                 : ["CAPABILITY_IAM"]
        Parameter overrides          : {}
        Signing Profiles             : {}

Initiating deployment
=====================

        Uploading to apitest-app/9a3bcae16046c5ec82be9d9bd2aaa848.template  3113 / 3113  (100.00%)


Waiting for changeset to be created..

Error: Failed to create changeset for the stack: apitest-app, ex: Waiter ChangeSetCreateComplete failed: Waiter encountered a terminal failure state: For expression "Status" we matched expected path: "FAILED" Status: FAILED. Reason: Unresolved resource dependencies [ServerlessRestApi] in the Outputs block of the template

...
[default.deploy.parameters]
capabilities = "CAPABILITY_IAM"
confirm_changeset = true
resolve_s3 = true
s3_prefix = "apitest-app"   <--- ここ追加
region = "ap-northeast-1"   <--- ここ追加
profile = "XXX"             <--- ここ追加
image_repositories = []     <--- ここ追加
...

   # Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/myget/"
   Value: !Sub "https://${MyApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/myget/"
   ...  
   # Value: !Sub "https://${ServerlessRestApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/mypost/"
   Value: !Sub "https://${MyApi}.execute-api.${AWS::Region}.amazonaws.com/Prod/mypost/"
   ...

# なぜか template.yaml を指定しておかないといつまでもエラーが消えない様子。古い template.yaml をどこかで覚えている?
$ sam deploy -t template.yaml
...
Previewing CloudFormation changeset before deployment
======================================================
Deploy this changeset? [y/N]: y    # <--- 反映していいか聞いてきているので Y
...
CloudFormation outputs from deployed stack
---------------------------------------------------------------------------------------------------------------------------------------------
Outputs
---------------------------------------------------------------------------------------------------------------------------------------------
Key                 MyGetFunction
Description         My Get Lambda Function ARN
Value               arn:aws:lambda:ap-northeast-1:9999999999999:function:apitest-app-MyGetFunction-zzzz1

Key                 MyPostFunctionIamRole
Description         Implicit IAM Role created for My Post function
Value               arn:aws:iam::9999999999999:role/apitest-app-MyPostFunctionRole-zzzz2

Key                 MyPostApi
Description         API Gateway endpoint URL for Prod stage for my post function
Value               https://xxxxxxx.execute-api.ap-northeast-1.amazonaws.com/Prod/mypost/

Key                 MyGetApi
Description         API Gateway endpoint URL for Prod stage for my get function
Value               https://xxxxxxx.execute-api.ap-northeast-1.amazonaws.com/Prod/myget/

Key                 MyPostFunction
Description         My Post Lambda Function ARN
Value               arn:aws:lambda:ap-northeast-1:9999999999999:function:apitest-app-MyPostFunction-zzzz3

Key                 MyGetFunctionIamRole
Description         Implicit IAM Role created for My Get function
Value               arn:aws:iam::9999999999999:role/apitest-app-MyGetFunctionRole-zzzz4
---------------------------------------------------------------------------------------------------------------------------------------------

Successfully created/updated stack - apitest-app in ap-northeast-1

$ git add .
    $ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        modified:   samconfig.toml
        modified:   template.yaml
$ git commit -m "add deploy paramters"

$ cp client/local.html client/aws.html

$ google-chrome client/aws.html

$ git add .
$ git status
On branch master
Changes to be committed:
  (use "git restore --staged <file>..." to unstage)
        new file:   client/aws.html
$ git commit -m "add client/aws.html"

$ tree .
.
├── README.md
├── __init__.py
├── client
│   ├── aws.html
│   └── local.html
├── events
│   └── event.json
├── my_get_function
│   ├── __init__.py
│   ├── app.py
│   └── requirements.txt
├── my_layer
│   └── python
│       └── db_info.py
├── my_post_function
│   ├── __init__.py
│   ├── app.py
│   └── requirements.txt
├── samconfig.toml
├── template.yaml
└── tests
    ├── __init__.py
    ├── integration
    │   ├── __init__.py
    │   └── test_api_gateway.py
    ├── requirements.txt
    └── unit
        ├── __init__.py
        └── test_handler.py

9 directories, 20 files

...
[default.global.parameters]
stack_name = "apitest-app"
parameter_overrides = [
  "UserName=testman",
  "UserType=1111",
]
...

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  apitest-app

  Sample SAM Template for apitest-app  

Parameters:  # <--- Paramters節を追記。外部参照パラメータを定義
  UserName:
    Type: String
  UserType:
    Type: Number
...
# myget/mypostに外部パラメータ参照定義追加
Resources:
  MyGetFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: my_get_function/
      Handler: app.lambda_handler
      Runtime: python3.11
      Architectures:
        - x86_64
      Events:
        MyGet:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /myget
            Method: get
            RestApiId:
              Ref: MyApi
      Environment:  # <--- Environment節を追記
        Variables:
          UserName: !Ref UserName
          UserType: !Ref UserType
      Layers:
        - !Ref MyLayer

  MyPostFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: my_post_function/
      Handler: app.lambda_handler
      Runtime: python3.11
      Architectures:
        - x86_64
      Events:
        MyGet:
          Type: Api # More info about API Event Source: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#api
          Properties:
            Path: /mypost
            Method: post
            RestApiId:
              Ref: MyApi
      Environment:  # <--- Environment節を追記
        Variables:
          UserName: !Ref UserName
          UserType: !Ref UserType
      Layers:
        - !Ref MyLayer

import os  # <--- 環境変数アクセスに必要
...
        "body": json.dumps({
            "message": "xxx api(host:{}/port:{}/)".format(dbinfo.connections['host'], dbinfo.connections['port']),
            "UserName": os.environ.get('UserName', "UserNameError"), # <-- ここに外部参照追加(UserName)
            "UserType": os.environ.get('UserType', 9999), # <-- ここに外部参照追加(UserType)
            # "location": ip.text.replace("\n", "")
        }),
...

$ sam build -t template.yaml --config-file samconfig.toml
$ sam local start-api -t template.yaml --config-file samconfig.toml

# 別ターミナル
$ google-chrome client/local.html

$ sam build -t template.yaml --config-file samconfig.toml
$ sam deploy -t template.yaml --config-fiele samconfig.toml
...
        Deploying with following values
        ===============================
        Stack name                   : apitest-app
        Region                       : ap-northeast-1
        Confirm changeset            : True
        Disable rollback             : False
        Deployment s3 bucket         : aws-sam-cli-managed-default-samclisourcebucket-1eli41thgg4jk
        Capabilities                 : ["CAPABILITY_IAM"]
        Parameter overrides          : {"UserName": "testman", "UserType": "1111"}  <--- ここに外部パラメータが表示される
        Signing Profiles             : {}
...
Previewing CloudFormation changeset before deployment
======================================================
Deploy this changeset? [y/N]:y <--- 変更があるので更新確認 y
...
Successfully created/updated stack - apitest-app in ap-northeast-1

# 上記、更新が成功した旨、表示されればOK。また接続先も変更されることはない
# 別ターミナル
$ google-chrome client/aws.html

$ aws cloudformation delete-stack --stack-name apitest-app --profile XXX

<!doctype html>
<html lang="en">
  <head>
    <!-- Required meta tags -->
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">

    <!-- Bootstrap CSS -->
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
    <title>aws</title>
  </head>
  <body>
    <h1>aws</h1>
    <div>
      <label for="requestUrlInput" class="form-label">request url</label>
      <input type="text" class="form-control" id="requestUrlInput" placeholder="https://3k3wg0s3w4.execute-api.ap-northeast-1.amazonaws.com/Prod">
    </div>
    <button type="button" class="btn btn-primary" onclick="GetSimpleRequest()">GET単純リクエスト</button>
    <button type="button" class="btn btn-primary" onclick="GetNonSimpleRequest()">GET非単純リクエスト</button>
    <br>
    <button type="button" class="btn btn-warning" onclick="PostSimpleRequest()">POST単純リクエスト</button>
    <button type="button" class="btn btn-warning" onclick="PostNonSimpleRequest()">POST非単純リクエスト</button>

    <script>
    // ↓ここから追加
    let request_url = 'https://3k3wg0s3w4.execute-api.ap-northeast-1.amazonaws.com/Prod'
    // input要素を取得
    var inputElement = document.getElementById("requestUrlInput");
    inputElement.value = request_url
    // input要素の値が変化したときのイベントリスナーを設定
    inputElement.addEventListener("change", function() {
        // グローバル変数に新しい値を代入
        request_url = this.value;
    });
    // ↑ここまで追加。以下は request_url を参照するように変更している
    // GET 単純リクエスト
    function GetSimpleRequest() {
        axios({
            method: 'get',
            url: `${request_url}/myget`,
            headers: {
                'Content-Type': 'text/plain'
            },
        })
        .then(function (response) {
           console.log(response);
        })
        .catch(function (error) {
           console.log(error);
        });
     }
    // GET 非単純リクエスト
    function GetNonSimpleRequest() {
        axios({
            method: 'get',
            url: `${request_url}/myget`,
            headers: {
                'Content-Type': 'application/json'
            },
            data: {
                message: 'Hello, world!'
            }
        })
        .then(function (response) {
            console.log(response);
        })
        .catch(function (error) {
            console.log(error);
        });
     }

    // POST 単純リクエスト
    function PostSimpleRequest() {
        axios({
            method: 'post',
            url: `${request_url}/mypost`,
            headers: {
                'Content-Type': 'text/plain'
            },
            data: 'Hello, world!'
        })
        .then(function (response) {
            console.log(response);
        })
        .catch(function (error) {
            console.log(error);
        });
         // alert("Simple");
     }
    // POST 非単純リクエスト
    function PostNonSimpleRequest() {
        axios({
            method: 'post',
            url: `${request_url}/mypost`,
            headers: {
                'Content-Type': 'application/json'
            },
            data: {
                message: 'Hello, world!'
            }
        })
        .then(function (response) {
            console.log(response);
        })
        .catch(function (error) {
            console.log(error);
        });
         // alert("NonSimple");
     }
    </script>

    <!-- Optional JavaScript; choose one of the two! -->
    <script src="https://cdn.jsdelivr.net/npm/axios/dist/axios.min.js"></script>

    <!-- Option 1: Bootstrap Bundle with Popper -->
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.bundle.min.js" integrity="sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM" crossorigin="anonymous"></script>

    <!-- Option 2: Separate Popper and Bootstrap JS -->
    <script src="https://cdn.jsdelivr.net/npm/@popperjs/core@2.9.2/dist/umd/popper.min.js" integrity="sha384-IQsoLXl5PILFhosVNubq5LC7Qb9DXgDA9i+tQ8Zj3iwWAwPtgFTxbJ8NT4GN1R8p" crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.min.js" integrity="sha384-cVKIPhGWiC2Al4u+LWgxfKTRIcfu0JTxR+EQDz/bgldoEyl4H0zUF0QKbrJ0EcQF" crossorigin="anonymous"></script>
  </body>
</html>

...
  MyApi:
    Type: AWS::Serverless::Api
    Properties:
      StageName: Prod
      EndpointConfiguration: REGIONAL  # ここに追加
      Cors:
        AllowOrigin: "'*'"
        AllowMethods: "'OPTIONS,GET,POST'"
        AllowHeaders: "'Content-Type'"
...

# 全体に適用する場合：
Globals:
  Function:
    Timeout: 3
    VpcConfig: # <--- vpcはセキュリティグループとサブネットから自動判断される様子
      SecurityGroupIds:
        - sg-0abcd1234efgh5678 # <--- 事前にセキュリティグループ作成必要
      SubnetIds:
        - subnet-a1b2c3d4 # <--- 事前にサブネット１作成必要
        - subnet-e5f6g7h8 # <--- 事前にサブネット２作成必要

# API 単位に適用する場合：
MyGetFunction:
  Type: AWS::Serverless::Function
  Properties:
    ...
    VpcConfig: # <--- vpcはセキュリティグループとサブネットから自動判断される様子
      SecurityGroupIds:
        - sg-0abcd1234efgh5678 # <--- 事前にセキュリティグループ作成必要
      SubnetIds:
        - subnet-a1b2c3d4 # <--- 事前にサブネット１作成必要
        - subnet-e5f6g7h8 # <--- 事前にサブネット２作成必要

Resources:
  MyVPC:
    Type: 'AWS::EC2::VPC'
    Properties:
      CidrBlock: 10.0.0.0/16

  MySubnet:
    Type: 'AWS::EC2::Subnet'
    Properties:
      VpcId: !Ref MyVPC
      CidrBlock: 10.0.1.0/24

  MySecurityGroup:
    Type: 'AWS::EC2::SecurityGroup'
    Properties:
      GroupDescription: My security group
      VpcId: !Ref MyVPC
    
    ...
    VpcConfig:
      SecurityGroupIds:
        - !Ref MySecurityGroup
      SubnetIds:
        - !Ref MySubnet
    ...

  MyApi:
    Type: AWS::Serverless::Api
    Properties:
      StageName: Prod
      Domain: # <--- Domain節追加
          DomainName: example.com # ここにドメイン名を指定
          CertificateArn: arn:aws:acm:us-east-1:123456789012:certificate/abc123def456 # ここに ACM 証明書の ARN を指定
      Cors:
        AllowOrigin: "'*'"
        AllowMethods: "'OPTIONS,GET,POST'"
        AllowHeaders: "'Content-Type'"