To support token based authentication

[sgadisetti]

The change is to support token based authentication using OAuth2

[liderman]

It seems to me that it is not worth adding a new dependency just to put down one HTTP header. This can be done like this:

if c.AuthorizationHeader != "" {
    req.Header.Set("Authorization", c.AuthorizationHeader)
} else {
    req.SetBasicAuth(c.apiUser, c.apiPassword)
}

[sgadisetti]

Hi @liderman Thanks for quick review!

As Oauth2 provides different popular flows like Authorization Code Flow, Client Credentials Flow.. and also supports refresh token, I thought it would be good to use it and client applications can pass the token that it gets from authorization server as is without having any conversion in the client code.

Token object as follows..

type Token struct {
// AccessToken is the token that authorizes and authenticates
// the requests.
AccessToken string json:"access_token"

// TokenType is the type of token.
// The Type method returns either this or "Bearer", the default.
TokenType string `json:"token_type,omitempty"`

// RefreshToken is a token that's used by the application
// (as opposed to the user) to refresh the access token
// if it expires.
RefreshToken string `json:"refresh_token,omitempty"`

// Expiry is the optional expiration time of the access token.
//
// If zero, TokenSource implementations will reuse the same
// token forever and RefreshToken or equivalent
// mechanisms for that TokenSource will not be used.
Expiry time.Time `json:"expiry,omitempty"`

// raw optionally contains extra metadata from the server
// when updating a token.
raw interface{}

}

Please let me know your thoughts. I am flexible either way!

[liderman]

@sgadisetti
You are using the "SetAuthHeader" method, which only sets the "Authorization" HTTP header:
https://cs.opensource.google/go/x/oauth2/+/refs/tags/v0.9.0:token.go;l=84

// SetAuthHeader sets the Authorization header to r using the access
// token in t.
//
// This method is unnecessary when using Transport or an HTTP Client
// returned by this package.
func (t *Token) SetAuthHeader(r *http.Request) {
	r.Header.Set("Authorization", t.Type()+" "+t.AccessToken)
}

[sgadisetti]

@liderman Please check the latest changes and see if they make sense!

[liderman]

Why are files README.md and go.sum deleted?

[liderman]

Why was this file removed? Looks like a mistake

[sgadisetti]

I am sorry. Something got messed up in my local during previous pull request. Files are restored now. Please check!

[liderman]

Why was this file removed? Looks like a mistake

[sgadisetti]

I am sorry. Something got messed up in my local during previous pull request. Files are restored now. Please check!