[Issue #193] Integrate OAuth2 Authentication into Core Repository

[prayascoriolis]

[Issue #193] Implement OAuth2 Authentication in Core Repository

Fixes Issue: 193

PR Branch
https://github.com/prayascoriolis/zerocode/tree/ISSUE-193-OAuth2-Support

Motivation and Context

The integration of OAuth2 authentication into the core repository is a key enhancement that will make the library more versatile and secure. By aligning this effort with the successful example from the zerocode-hello-world repository, you are paving the way for a robust authentication mechanism that can be leveraged across various use cases.

PR Description:

This pull request integrates OAuth2 authentication into the core repository. The following tasks have been undertaken:

1. Created a unit runner class with OAuth2 specification.
2. Included necessary Java, properties, and JSON files for the custom HTTP client.
3. Made minor path adjustments in the Java files to ensure successful test execution.

Checklist:

• New Unit tests were added

• Integration tests were added

• Test names are meaningful

• Feature manually tested and outcome is successful

• PR doesn't break any of the earlier features for end users

• Branch build passed in CI

• No 'package.*' in the imports

• Http test added to http-testing module(if applicable)

• Not applicable. The changes did not affect Kafka automation flow

[authorjapps]

@prayascoriolis , can you rebase or merge "master" to this PR branch please?

[prayascoriolis]

@authorjapps i've merged branch "master" to this PR branch.

[authorjapps]

@authorjapps i've merged branch "master" to this PR branch.

ok. Thank you. Let me check if the build gets through(earlier it was stuck due to the Ubuntu image issue from GitHub Actions)

[authorjapps]

You can check here as well @prayascoriolis :
https://github.com/authorjapps/zerocode/pull/676/checks

[prayascoriolis]

You can check here as well @prayascoriolis : https://github.com/authorjapps/zerocode/pull/676/checks

Thankyou, @authorjapps, All the checks have passed.

[nirmalchandra]

@prayascoriolis , thanks for trying to impl this.
Here are some observations and suggestions:

• What you have implemented is a "refresh token" flow
  • See here how "refresh_token" flow works(Section 6): https://datatracker.ietf.org/doc/html/rfc6749#section-6
  • i.e. "Refreshing an Access Token"
• What is needed is preferrably is: "access_token" flow
  • See here (Section 4.4.2 and 4.4.3): https://datatracker.ietf.org/doc/html/rfc6749#section-4.4.2
  • This flow should be implemented I think
• I think both flow should be supported, but "access_token" first, then "refresh_token"

[prayascoriolis]

@authorjapps @nirmalchandra I've completed the end to end implementation of oauth2 access token alog with refresh_token, can you please review it ?