OAuth-Upstream-Call.js

var auth0OAuthClientCredMiddleware = new TykJS.TykMiddleware.NewMiddleware({});

// "Cache"
zendeskAccessToken = {
  token: "",
  expiry: 0,
}

salesforceAccessToken = {
  token: "",
  expiry: 0,
}

auth0OAuthClientCredMiddleware.NewProcessRequest(function(request, session, spec) {
  log("OAuth2 Access Token Flow Init")
  
  // There is a separate access token for EACH API (zendesk, salesforce, etc)
  // This plugin gets called by each API
  // Pulls access token from cache
  accessToken = null
  switch (spec.config_data.upstream_client) {
      case "zendesk": 
        accessToken = zendeskAccessToken
        log("Using zendesk token!")
        break;
      case "salesforce":
        accessToken = salesforceAccessToken
        log("Using salesforce token!")
        break;
  }

  // If no access token, should return early with error
  // Means we haven't set up an API correctly
  if (!accessToken) {
    log("NO upstream vendor found")
    return auth0OAuthClientCredMiddleware.ReturnData(request, {});
  }
  
  // Need to refresh the upstream token..
  log(accessToken.token)
  log(accessToken.expiry)
  if (accessToken.expiry < new Date().getTime()) {

    log("EXPIRED token.. fetching new one!")

    //Make api call to IDP
    oauthClientRequest = JSON.stringify({
      "Method": "POST",
      "Body": "{\"client_id\":\"{PASTE-YOUR-OWN-CLIEND-ID}\",\"client_secret\":\"{PASTE-YOUR-OWN-CLIEND-SECRET}\",\"audience\":\"auth0-id\",\"grant_type\":\"client_credentials\"}",
      "Headers": {"content-type":"application/json"},
      "Domain": "https://webhook.site",
      "Resource": "/8b0f6813-4b91-4345-b8fb-975dae93e161"
    });

    rawResponse = TykMakeHttpRequest(oauthClientRequest);
    usableResponse = JSON.parse(rawResponse);

    log("IDP Response Code: " + usableResponse.Code);
    log("IDP Response Body: " + usableResponse.Body); 

    // Save to "cache"
    newToken = "FAKETOKEN"
    newExpiry = Date.now() + 10000; // 10 seconds
    
    // Should be a separate function, but laziness
    switch (spec.config_data.upstream_client) {
      case "zendesk": 
        zendeskAccessToken.token = newToken
        zendeskAccessToken.expiry = newExpiry
        log("Using zendesk token!")
        break;
      case "salesforce":
        salesforceAccessToken.token = newToken
        salesforceAccessToken.expiry = newExpiry
        log("Using salesforce token!")
        break;
    }

  }
  
  request.SetHeaders["Authorization"] = "Bearer " + newToken;


  log("Virtual endpoint about to end")
  log ('----')
  return auth0OAuthClientCredMiddleware.ReturnData(request, {});
});

// Log that middleware is initialised
log("JavaScript middleware is initialised");