(Ruby) Auth0 Server-to-Server Access Token (Client Credentials flow)

Demonstrates how to obtain an Auth0 access token using client credentials (client_id and client_secret).

This is just a matter of duplicating this CURL command:

curl --request POST
  --url 'https://chilkat.auth0.com/oauth/token' \
  --header 'content-type: application/json' \
  --data '{"grant_type":"client_credentials","client_id": "xxxx","client_secret": "xxxx","audience": "https://api.example.com/geocoding/v1/"}'

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# We want to duplicate this curl command:
# 
# curl --request POST
#   --url 'https://chilkat.auth0.com/oauth/token' \
#   --header 'content-type: application/json' \
#   --data '{"grant_type":"client_credentials","client_id": "my_client_id","client_secret": "my_client_secret","audience": "https://api.example.com/geocoding/v1/"}'

# Build the JSON body of the request.
json = Chilkat::CkJsonObject.new()
json.UpdateString("grant_type","client_credentials")
json.UpdateString("client_id","AUTH0-CLIENT-ID")
json.UpdateString("client_secret","AUTH0-CLIENT-SECRET")
json.UpdateString("audience","https://api.example.com/geocoding/v1/")

# IMPORTANT: You would use your own url.  You would not use "chilkat.auth0.com".  
# Instead you would use "your_name.auth0.com"
http = Chilkat::CkHttp.new()
# resp is a CkHttpResponse
resp = http.PostJson3("https://chilkat.auth0.com/oauth/token","application/json",json)
if (http.get_LastMethodSuccess() != true)
    print http.lastErrorText() + "\n";
    exit
end

# A 200 response status code indicates success.  In the success case, the response body
# contains the JSON access token, such as: 
# {
#   "access_token": "eyJz93a...k4laUWw",
#   "token_type":"Bearer",
#   "expires_in":86400
# }
# 

print "response status code = " + resp.get_StatusCode().to_s() + "\n";

# The repsonse is JSON if successful and also JSON for errors.
jsonResp = Chilkat::CkJsonObject.new()
jsonResp.put_EmitCompact(false)
jsonResp.Load(resp.bodyStr())

if (resp.get_StatusCode() != 200)
    # The response body contains error information in JSON format.
    print jsonResp.emit() + "\n";

    # An example of an error response:
    # 		{
    # 		  "error": "access_denied",
    # 		  "error_description": "Client is not authorized to access \"https://api.example.com/geocoding/v1/\". You might probably want to create a \"client-grant\" associated to this API. See: https://auth0.com/docs/api/v2#!/Client_Grants/post_client_grants"
    # 		}
    exit
end

print "Success!" + "\n";
print jsonResp.emit() + "\n";

# A successful JSON response body looks like this:

# {
#   "access_token": "eyJz93a...k4laUWw",
#   "token_type":"Bearer",
#   "expires_in":86400
# }