[AWS] Create a Python Lambda environment with CodeStar and do Hello World

Introduction

Overview

Recently, we are developing using AWS CodeStar. CodeStar is roughly understood as a service that combines a CI / CD service and a dashboard. The CI / CD tool is also packaged and created, so the code you write will be reflected immediately, which is convenient when you want to give it a try. However, when I made it (I am a beginner of AWS), I often stumbled around the authority. We plan to update S3 access, Lambda VPC placement, and EC2 projects from time to time.

First, edit and push the code with a local text editor to check the changes.

Premise

--Work date: 2020/4/11 --Local environment

• PC：Mac
• OS：Catalina --Installed commands: Git CLI, AWS CLI --AWS environment --User: root --AWS Region: Tokyo (ap-northeast-1)

• ** Please note that as of April 11, 2020, CodeStar in the Tokyo region does not support Cloud9 as a development environment **

CodeStar project creation procedure

1. Open the CodeStar service by searching for codestar from the AWS Management Console

2. Create a new project

3. This time select the "Python Web Service Lambda" template

4. This time, the project name is "hello-world-codestar", the project ID is "codestar-test", and the repository uses CodeCommit.

• ** Please note that the project ID can be edited up to 15 characters, and this ID will affect various parts of the service created by CodeStar (URL, service name, ARN) described later and cannot be changed **

5. Press "Create Project" with the "AWS CodeStar ~ (Omitted) ~" checkbox checked.

• ** Please note that related services will be deployed as soon as you press **
• ** Also note that public URLs will be published **
• 7-8 services are automatically created by creating a CodeStar project, so if you create them carelessly, the environment will be messed up at once ...

6. Creating repository ... (When the repository is created, the URL of the repository created in CodeCommit will be displayed.) Select "Skip".

• You can set the code editing environment later.

7. Creating a project ... after the creation is completed

8. In this state, you can check the response from Lambda of the initial template by accessing "Application Endpoint" in the dashboard.

Code editing on a local PC ~ Text editor ~

1. Select "Connect to Tool" from the dashboard screen of the created project and copy the repository URL.

• Target user Git credentials

2. Clone the URL copied by the CLI of the local machine, in the case of the first clone [Git credentials](https://docs.aws.amazon.com/ja_jp/codestar/latest/userguide/getting-started.html#git- You need to enter the user name / password of credentials)

3. The hierarchy of the cloned code is as follows, this time edit "index.py" and check that the response of Lambda changes

• I won't go into detail here, but you can test Lambda build tests and update deployment settings by properly setting buyspec.yml, template.yml, and IAM roles / policies.

4. Edit and save index.py, in the example below, "Code Star!" Is added to the output value.

index.py

import json
import datetime


def handler(event, context):
    data = {
        # 'output': 'Hello World',
        'output': 'Hello World CodeStar!',
        'timestamp': datetime.datetime.utcnow().isoformat()
    }
    return {'statusCode': 200,
            'body': json.dumps(data),
            'headers': {'Content-Type': 'application/json'}}

5. Add → commit → push to reflect the changes in the remote repository

• At this time, push will fail unless the AWS CLI configuration exists in the environment where the cloned repository exists. The setting method is here /cli-chap-configure.html)

6. If the push is successful, the PipeLine status will be updated on the CodeStar dashboard.

7. Confirm that Deploy is completed and the status of all phases is Green, access the endpoint of the app, and confirm that the code change is reflected.

at the end

--The following describes how to create a CodeStar project and how to edit code with a text editor, but you can also edit code and push with IDE. ――Looking back, I realized that there is a surprising process just by editing and pushing locally.

(Remarks) About CodeStar project ID

Select the project at the bottom left of the dashboard

When opened, you will see the project details and a list of resources created by CodeStar. As you can see, the project ID set in creation step 4 is used everywhere, which is why you need to be careful because the project ID cannot be changed as mentioned above. (If anyone knows how to change the project ID, please let me know!)