[PHY-29] Create basic `etsy` package

[bennobuilder]

DoD

• [X] Etsy API is integrated based on the POC backend
• [X] Think about good solution regarding auth flow which requires the use of the 'Authorization Code Flow' as Etsy does not offer any 'Client Credentials Flow'

_{From SyncLinear.com | PHY-29}

[bennobuilder]

Options

Option 1: Puppeteer Login

A browser automation like Puppeteer will be used to complete the Etsy OAuth2 Flow automatically by logging in with the user data in a stripped down Chrome browser. However, this method requires deactivating 2FA, which is not recommended for security reasons.

Disadvantages

• Doesn't work with 2FA
• Increases bundle size
• Considered an antipattern

Advantages

• No user interaction required (if 2FA disabled)

Option 2: Manual Login

The refresh token will be set as an environment variable with its expiration timestamp. The refresh token has to be manually and locally fetched by calling http://localhost:9000/v1/auth/etsy/oauth/challenge (this route is only accessible on StageLOCAL) and completing the OAuth2 Flow manually with 2FA. Once the refresh token is received, it has to be added to the environment variable with the expiration timestamp wherever the @pda/etsy package is in use (backend services only). To avoid forgetting to renew the refresh token, an alert will be set up. Additionally, the returned expiration timestamp has a five-day buffer.

Disadvantages

• More complex process.
• Requires user interaction as soon as the refresh token expires.

• Advantages

• Works with 2FA
• More secure (due to 2FA)
• No antipattern (auth flow is done as expected)
• Easier to set up

Decision

• Option 2
• Has more advantages and is overall cleaner