Configuring multiple API paths with Azure Application Gateway

Question

Configuring multiple API paths with Azure Application Gateway

Pallab Chakraborty 401

I have this query. Can i get a reply as to how to configure this

My query is in the below link

https://stackoverflow.com/questions/75631445/how-to-use-multiple-wildcard-hosttype-in-azure-application-gateway-for-various-a

KapilAnanth 49,851 Reputation points Moderator

2023-03-07T04:57:34.0566667+00:00
@Anonymous

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I am afraid that your requirement is not clear.

From what I can see,

You have a MultiSite Listener with HostType Single and HostName my-api-dev.contoso.com

This hostname represents the BE WebApp.

Since your backend also has a custom domain as "my-api-dev.contoso.com",

All the calls to the BE WebApp with this domain should succeed.

Your examples, "my-api-dev.contoso.com//token", "my-api-dev.contoso.com/api/shippingnotice" should work and App Gw will redirect the request to the BE Webapp as long as the Listener is attached to the BackendPool containing the BE Webapp via a Request Routing Rule.

Can you please elaborate what issue you are facing here?

Cheers,

Kapil
Pallab Chakraborty 401 Reputation points

2023-03-07T12:17:00.9033333+00:00

@KapilAnanth The user reported that when they are trying to get a token for the API and trying to access the API from Mulesoft which is in AWS, they are getting :

HTTP/1.1 403 Forbidden

Connection: close

If they use Postman and tries the URL from within the organization VPN, it works fine. This is not working when trying to hit the App Gateway from outside

So what i have done is in the screenshot attached, will this make any difference you think? Any idea if the backend is exposed using the URL as mentioned in my question, why then are the APIs not working which are like sub pages of the backend
KapilAnanth 49,851 Reputation points Moderator

2023-03-07T12:55:18.5133333+00:00
@Anonymous

Was this set up working previously?

Or a completely new setup?

Also, if you are redirecting different paths to the same Backend Pool with same HTTP Settings, then why not just use the default backend pool (and not use Path based routing at all).

This is how Path Based Routing is expected to be configured.

Wrt to the fact that the same is working within the Organisation,

Do you mean the set-up is working with a Private Listener?

And not working with a Public Listener?

Via Internet, (i.e, Outside the Organisation) , if you bypass the App gateway and directly access the BE Webapp, does it work?

It is quite possible that the culprit is BE Webapp and not App gateway. To check this,
Please check the AccessLogs and check if the backend is giving a 4XX error
The parameter "httpStatus" and "serverStatus" should tell us if the HTTP Response is from the Appgateway or WebApp.

Cheers,

Kapil
KapilAnanth 49,851 Reputation points Moderator

2023-03-08T09:02:50.0266667+00:00

@Anonymous

Could you please provide an update on this post?

Kindly let us know if the below helps or you need further assistance on this issue.

Thanks,

Kapil
Pallab Chakraborty 401 Reputation points

2023-03-08T12:30:59.39+00:00

@KapilAnanth This is a new setup. Front End web app works fine, but issue is with the API, which is the BE web app. We didn't try accessing the BE just from the internet. It won't serve the purpose. The API needs to be called from Mulesoft which is sitting in AWS using App Gateway, that is the reason we had to expose these web apps as they are behind private endpoints

After making the changes and putting multiple paths, i am waitin for an answer from the user

Once i hear back from the user, i will update you here about the status

Thanks
KapilAnanth 49,851 Reputation points Moderator

2023-03-10T09:52:28.56+00:00

@Anonymous

Reaching out to check if there are any updates on this.

Please let us know if we can be of any further assistance here.

Thanks,

Kapil
KapilAnanth 49,851 Reputation points Moderator

2023-03-13T03:35:07.5833333+00:00

@Anonymous

May I know if you got a chance to get any details from the user?

Please let me know if you are facing any challenges or if there are any follow-up questions, I shall be glad to address them.

Thanks,

Kapil
Pallab Chakraborty 401 Reputation points

2023-03-14T19:53:35.86+00:00

Hello,not yet.I will revert back if things do not work after the last changes.Thanks

Your answer

KapilAnanth 49,851 Reputation points Moderator

2023-03-07T04:57:34.0566667+00:00

@Anonymous

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I am afraid that your requirement is not clear.

From what I can see,

You have a MultiSite Listener with HostType Single and HostName my-api-dev.contoso.com

This hostname represents the BE WebApp.

Since your backend also has a custom domain as "my-api-dev.contoso.com",

All the calls to the BE WebApp with this domain should succeed.

Your examples, "my-api-dev.contoso.com//token", "my-api-dev.contoso.com/api/shippingnotice" should work and App Gw will redirect the request to the BE Webapp as long as the Listener is attached to the BackendPool containing the BE Webapp via a Request Routing Rule.

Can you please elaborate what issue you are facing here?

Cheers,

Kapil
Pallab Chakraborty 401 Reputation points

2023-03-07T12:17:00.9033333+00:00

@KapilAnanth The user reported that when they are trying to get a token for the API and trying to access the API from Mulesoft which is in AWS, they are getting :

HTTP/1.1 403 Forbidden

Connection: close

If they use Postman and tries the URL from within the organization VPN, it works fine. This is not working when trying to hit the App Gateway from outside

So what i have done is in the screenshot attached, will this make any difference you think? Any idea if the backend is exposed using the URL as mentioned in my question, why then are the APIs not working which are like sub pages of the backend
KapilAnanth 49,851 Reputation points Moderator

2023-03-07T12:55:18.5133333+00:00

@Anonymous

Was this set up working previously?

Or a completely new setup?

Also, if you are redirecting different paths to the same Backend Pool with same HTTP Settings, then why not just use the default backend pool (and not use Path based routing at all).

This is how Path Based Routing is expected to be configured.

Wrt to the fact that the same is working within the Organisation,

Do you mean the set-up is working with a Private Listener?

And not working with a Public Listener?

Via Internet, (i.e, Outside the Organisation) , if you bypass the App gateway and directly access the BE Webapp, does it work?

It is quite possible that the culprit is BE Webapp and not App gateway. To check this,
Please check the AccessLogs and check if the backend is giving a 4XX error
The parameter "httpStatus" and "serverStatus" should tell us if the HTTP Response is from the Appgateway or WebApp.

Cheers,

Kapil
KapilAnanth 49,851 Reputation points Moderator

2023-03-08T09:02:50.0266667+00:00

@Anonymous

Could you please provide an update on this post?

Kindly let us know if the below helps or you need further assistance on this issue.

Thanks,

Kapil
Pallab Chakraborty 401 Reputation points

2023-03-08T12:30:59.39+00:00

@KapilAnanth This is a new setup. Front End web app works fine, but issue is with the API, which is the BE web app. We didn't try accessing the BE just from the internet. It won't serve the purpose. The API needs to be called from Mulesoft which is sitting in AWS using App Gateway, that is the reason we had to expose these web apps as they are behind private endpoints

After making the changes and putting multiple paths, i am waitin for an answer from the user

Once i hear back from the user, i will update you here about the status

Thanks
KapilAnanth 49,851 Reputation points Moderator

2023-03-10T09:52:28.56+00:00

@Anonymous

Reaching out to check if there are any updates on this.

Please let us know if we can be of any further assistance here.

Thanks,

Kapil
KapilAnanth 49,851 Reputation points Moderator

2023-03-13T03:35:07.5833333+00:00

@Anonymous

May I know if you got a chance to get any details from the user?

Please let me know if you are facing any challenges or if there are any follow-up questions, I shall be glad to address them.

Thanks,

Kapil
Pallab Chakraborty 401 Reputation points

2023-03-14T19:53:35.86+00:00

Hello,not yet.I will revert back if things do not work after the last changes.Thanks

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Configuring multiple API paths with Azure Application Gateway

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