Unable to reach endpoint after QnAMaker migration - botframework

Question

We have a bot that has been in production for several months. The bot configured with the preview service is working great.
So I followed the steps in the migration document. I created a QnA Service in Azure, then created the knowledgebase. I imported my knowledgebase, save/trained, and published.
In my web.config I replaced the following values:
<add key="QnAKnowledgeBaseId" value="foo" />
<add key="QnaSubscriptionKey" value="bar" />
<add key="QnaMakerUpdateKnowledgeBaseEndpoint" value="https://westus.api.cognitive.microsoft.com/qnamaker/v2.0/knowledgebases" />
I used the values given after publishing my knowledgebase, so
POST /knowledgebases/<QnAKnowledgeBaseId>/generateAnswer
Host: <QnaMakerUpdateKnowledgeBaseEndpoint>
Authorization: EndpointKey <QnaSubscriptionKey>
After changing these three lines my bot stops retrieving answers. This leads me to suspect either 1) I have the source for these datapoints is incorrect, or 2) Larger changes are required to convert in my situation. Can anyone guide me in the right direction?
Edit: Ultimately my issue was the bot's original developer hiding the QnAMaker's endpoing somewhere. I'm still not sure where, the url isn't in the web.config or in any of the azure settings. I overwrote it and all seems fine.
The answers below were more clear to me than the official documentation, even if they just affirmed what I thought was the right answer on my initial reading. Great job people.

Answer 1

The new v4 uses an azure website for its generateAnswer end point with a different scheme inside the authorisation header. Log into the new v4 ui do a publish and you will see the url example has changed.
Caught me out initially too. Their are a few changes to the api too qnaquestions collection is now qnalist and also qnaid is now just id.
You will need to thoroughly compare the api, especially if you have handrolled your client.
Happy to help
Phil

Answer 2

After you publish your knowledge base, you will find the endpoint details that can be used in your application or bot code. As Phil mentioned, it uses an azure website for its generateAnswer end point, which is different from old version QnA services.
old version QnA services:
So if you make the following request to get answers to a question with new knowledge base, it would not work.
https://westus.api.cognitive.microsoft.com/qnamaker/v2.0/knowledgebases/<QnAKnowledgeBaseId>/generateAnswer

Answer 3

After publishing when you get all the necessary settings info you can add then in code like this.
Use the host address which you get at the time of publishing in qnamaker.
QnADialog.cs
namespace Test.Qna
{
[Serializable]
[QnAMaker(authKey: "AuthKey", knowledgebaseId: "KnowledgebaseId", defaultMessage: "please rephrase, I could not understand.", scoreThreshold: 0.5, top: 1, endpointHostName: "https://yourAccount.azurewebsites.net/qnamaker")]
public class QnADialog : QnAMakerDialog
{}
}
For Node js you can do like this
var server = restify.createServer();
server.listen(process.env.port || process.env.PORT || 3978, function () {
console.log('%s listening to %s', server.name, server.url);
});
var connector = new builder.ChatConnector({
appId: process.env.MICROSOFT_APP_ID,
appPassword: process.env.MICROSOFT_APP_PASSWORD
});
var bot = new builder.UniversalBot(connector);
bot.set('storage', new builder.MemoryBotStorage());
server.post('/api/messages', connector.listen());
var recognizer = new cognitiveservices.QnAMakerRecognizer({
knowledgeBaseId: '5abcde-cbfb-4yuio-92c5-052d3a806e78',
authKey: 'eb7uy78y-8a64-4e75-98uj-7f89987b67bc',
endpointHostName: 'https://name.azurewebsites.net/qnamaker'
});
var basicQnAMakerDialog = new cognitiveservices.QnAMakerDialog({
recognizers: [recognizer],
defaultMessage: 'No match! Try changing the query terms!',
qnaThreshold: 0.3
});
bot.dialog('/', basicQnAMakerDialog);
Hope this will help.