[PLUGIN-1872] Added GrantType and Client Authentication for the HttpOauth2

[Amit-CloudSufi]

https://cdap.atlassian.net/browse/PLUGIN-1872

Update UI:

1. Grant Type: Refresh Token

2. Grant Type: Client Credentials and Client Authentication: Body

3. Grant Type: Client Credentials and Client Authentication: Request parameter

Older UI vs When pipeline upgraded to latest build

1. Older Pipeline:
   

2. Older pipeline upgraded to latest UI:
   
   

[itsankit-google]

How does UI looks like for existing pipelines?

I think we should handle the case where oauth2GrantType is null for older pipelines.

[itsankit-google]

please add unit tests

Add screenshots & test evidences in PR description.

[itsankit-google]

please create a JIRA and add it to PR title

[itsankit-google]

May I know the reference documentation used to implement this authentication flow?

AFAIK, in client_credentials flow there is only one request to get access token from oauth server:

Request

curl -X POST "https://auth.example.com/oauth/token" \
     -H "Content-Type: application/x-www-form-urlencoded" \
     -d "grant_type=client_credentials" \
     -d "client_id=your-client-id" \
     -d "client_secret=your-client-secret" \
     -d "scope=read:data"

Response

{
  "access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "token_type": "Bearer",
  "expires_in": 3600
}

I am unable to understand & find oauth2ClientAuthentication method used in this PR.

[vikasrathee-cs]

May I know the reference documentation used to implement this authentication flow?

AFAIK, in client_credentials flow there is only one request to get access token from oauth server:

Request

curl -X POST "https://auth.example.com/oauth/token" \
     -H "Content-Type: application/x-www-form-urlencoded" \
     -d "grant_type=client_credentials" \
     -d "client_id=your-client-id" \
     -d "client_secret=your-client-secret" \
     -d "scope=read:data"

Response

{
  "access_token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...",
  "token_type": "Bearer",
  "expires_in": 3600
}

I am unable to understand & find oauth2ClientAuthentication method used in this PR.

Hi Ankit, It was addressed in Design doc also for one of your comment. Also we got this from customer side, that in some cases they are passing details in query params and in some cases as part of the body. Postman interface also has both the options.

[itsankit-google]

At some places we are using OAuth2 and in some places we are using OAuth interchangeably. Please ensure we either use OAuth2 or OAuth so that it does not confuse people looking at the code.

[itsankit-google]

please fix build failures.

[Amit-CloudSufi]

please fix build failures.

Success. It failed sometime, due to connection timeout..