Feat/296 allow access from cross origin in lambda and api gateway

[taniguchiiqqq]

Overviews of implementation

Allow access from localhost:3000. I ensured that the CORS error were resolved using front app and my personal AWS env.

Review points

I began to think about whether I should define those addresses somewhere instead of hard coding. What do you think about it?

[hitohata]

These values are static, so I prefer defining them in the settings file.

I began to think about whether I should define those addresses somewhere instead of hard coding. What do you think about it?

How about hosting on the Dyanamo? Or, in the environment value?
If you get this value on the top of the code, it can be used for a whole until the lambda is shouted down. This means this value works as a constant while the lambda is alive. So, we don't need to get this value from the DB after the init phase.
https://docs.aws.amazon.com/lambda/latest/dg/lambda-runtime-environment.html

To the sake of understanding, I deployed a lambda function on our account of AWS named the "random". Please run the test. I set it to show a random value as a body. If you invoke it two more times, you will find the random value is completely the same.

Anyway for the speed of development, I approve this PR.

[taniguchiiqqq]

Thank you so much for sharing the idea and even making the example! I'll take a look later. for now I prioritize deploying this change