I can't get vNet integration between an Azure App Service / WebJob and it's connected Storage Account to work correctly. I have added both the App Service and the storage account to the same vNet and enabled service endpoint binding for Microsoft.Storage. From what I can see in the docs, this is what is needed to get the communication to work between the services. Unfortunately, I get this error in the WebJob log when I try to run it:
"Unhandled Exception: Microsoft.WindowsAzure.Storage.StorageException:
The remote server returned an error: (403) Forbidden. --->
System.Net.WebException: The remote server returned an error: (403)
Forbidden."
If I disable the firewall on the storage account everything works just fine.
All the services are placed in the same resource group and region (West Europe).
I have tried both the "normal" (with gateway) and the new (Preview) vNet integration version on the App Service and both are failing the same way.
I am not using ASE (App Service Environment).
I have also added the following exceptions on the storage firewall:
Storage firewall exceptions
First, when you allow the set of trusted Microsoft services to bypass the network rules. These services will then use strong authentication to access the storage account.
In this case, you may think Microsoft.Networking service will be allowed in firewall rule. But basically, VNet Integration does not mean App Service is inside a VNet. VNet Integration gives your web app access to resources in your virtual network but doesn't grant private access to your web app from the virtual network. We usually used to securely access the resource in a VNet.
If you want to put your App Service in a VNet, you need to deploy it in App Service Environment, then it's already in a VNet.
Alternatively, you could whitelist the outbound web app service IP address in the firewall rule of the storage account.
Hope this helps, feel free to let me know if you have any concerns.
I've struggled myself on this topic.
First off, if you're restricting access to storage using the firewall you need to add your VNET to the storage firewall. Use your delegate subnet when adding your VNET.
When you add the private link between your storage and your VNET, Azure creates a private DNS zone but your app doesn't automatically use it, even when integrated to the VNET.
You can find more here https://learn.microsoft.com/en-us/azure/app-service/web-sites-integrate-with-vnet
But specifically this passage applies:
After your app integrates with your VNet, it uses the same DNS server that your VNet is configured with. By default, your app won't work with Azure DNS private zones. To work with Azure DNS private zones, you need to add the following app settings:
WEBSITE_DNS_SERVER with value 168.63.129.16
WEBSITE_VNET_ROUTE_ALL with value 1
These settings send all of your outbound calls from your app into your VNet and enable your app to access an Azure DNS private zone. With these settings, your app can use Azure DNS by querying the DNS private zone at the worker level.
You can test the DNS resolution your app is using by opening the debug console and using the NameResolver command
NameResolver mystorageaccount.blob.core.windows.net or
NameResolver mystorageaccount.queue.core.windows.net
should return your private address. If not you have a DNS issue.
Related
I have two NodeJS App Services.
They can connect to each other with no problem using the URL which is created for App Services by default. (That is through the public internet.)
Then I successfully enabled VNet Integration for both App Services, and assigned the same VNet and also subnet two both of them.
How should I modify the connection URL now to connect to appservice2 from appservice1 (without using the URLs which are publicly available on the internet)?
I could not find any host name or IP address information in Azure Portal using which I could have successfully established the connection.
Thanks for any suggestions!
When you want two app services to connect to each other over a private network, there are generally two steps you have to take to set this up correctly. Note that the app service URL will always stay the same, it is only the networking part that changes.
Both app services should have vnet integration enabled, which allows the app service to route its traffic through the vnet.
If you want others (e.g. another app service) to connect to an app service via a vnet you can choose between:
a) Service endpoints
b) Private endpoints
Reading your question, I assume you completed the first step correctly. But you have to complete either step 2a or 2b to get this to work properly. I would recommend you choose service endpoints because they are more straightforward than working with private endpoints. Below you'll find a detailed description and considerations for every step.
1. Vnet Integration
The subnet you use as an integration subnet has to be a dedicated subnet. This means it is only used for vnet integration.
Only one app service plan can be used with this dedicated subnet, this one app service plan may include multiple app services.
If there is a network security group attached to that subnet, it needs to allow outbound traffic.
If there is an azure firewall attached to your vnet and you want to make a call to a public endpoint, it should allow outbound traffic.
Vnet route all should be enabled if you want all the outbound traffic to travel over the vnet.
If you want to read more, I would recommend reading this documentation.
Here is a simple example of how you would create vnet integration by selecting the dedicated subnet:
Service Endpoints
Service endpoints allow you to lock down inbound access to your app so that the source address must come from a set of subnets that you select.
Service endpoints are automatically provisioned by azure when you enable access restrictions to the app service.
This is a much simpler alternative to private endpoints.
Does not work in large-scale networks where you want to connect from an on-prem network to an azure vnet.
You may turn to this documentation to read about all the features and limitations of service endpoints.
Here is an example of how you would enable services endpoints for your app service by creating an access restriction:
Private Endpoints
Private endpoints also need a subnet, but you can connect as many private endpoints to the subnet as there are IP addresses available.
When you use private endpoints, you also need to have a private DNS zone. Otherwise, the app service URL does not resolve correctly to an IP address.
Private endpoints are more complex than service endpoints because of the extra subnet and DNS requirements.
Here is a nice tutorial that let's you set up an app service with private endpoint.
The following example shows you how to create a private endpoint for your app service. You have the option to let azure create a private DNS zone automatically, or you can do this manually:
If you want to access app services without public internet, then enabling VNET integration in those services alone won't be enough. You need to create a private endpoint that provides the IP from the virtual network to access the app service internally within the VNET and it also disables public access to the app service over the internet. Also please be aware that the private endpoint implementation will have some cost implications as well.
If your requirement is just to establish a secure connection between your virtual network & app service and to avoid access over the public internet, a service endpoint is the simplest solution. If you also need to access the app service from on-premises through an express route or Azure Gateway, a regionally peered virtual network, or a globally peered virtual network, Private Endpoint is the solution.
Steps to set up a service endpoint are detailed in the provisioning service endpoint link
Steps to set up a private endpoint are detailed in the connect to the web app using private endpoint link
Also if you want to deep dive into private endpoint configuration for app service, I would recommend you to read through the following tutorial
I have my APIs hosted on a azure windows virtual machine. I want that these APIs should be privately consumed by API management. If I make VM and APIM in same VNET and configure APIM as internal then my APIs exposed by APIM will not be accessed by public web app and If I make my APIM external then my developer portal will be publically accessible, which I dont want.
Is there any policy or outbound/inbound rule that can be configured so that APIs from VM, and APIM developer portal is not publically accessible?
From the document, if you select internal option in the virtual network of API Management services,
the API Management gateway and developer portal are accessible only
from within the virtual network via an internal load balancer. The
gateway can access resources within the virtual network.
In this case, you can deploy your APIM into a vNet following the common network configurations---dns and NSG rules. The API hosted VM should be able to resolve the develop portal with a private IP address.
I have two Allow rules in Access Restrictions for the API web app, the corporate network and the VNET subnet with a VM used for development. The API published to the App Service works as expected from the corporate network but returns Error 403 - This web app is stopped" when called from the VM.
I double checked the rule and the subnet in the rule (x.x.x.0/24) correctly reflects the VM's subnet.
What could cause this?
The VM is most likely using a public IP address to talk with the App Service, not its private IP address.
The request would need to be routed through the VM's VNET to the App Service in order for the private address to be used.
You could add the VM subnet instead of a private CIDR range x.x.x.0/24 in the rules of Access Restrictions for the API web app. You should enable service endpoints on both the networking side as well as the service that it is being enabled with. If service endpoints are not already enabled with Microsoft.Web for the subnet that you selected, it will automatically be enabled for you unless you check the box asking not to do that.
When you finish it, you will find a virtual network/subnet as the source of the rule.
For more reference, you could get Azure App Service Access Restrictions.
I am currently working with a client that requires access to all Azure resource locking down as much as possible and I am having problems with the Storage Account that is utilised by our Azure Functions.
With the Firewalls and Virtual Networks blade in portal set to "All Networks" I am able to deploy to the Function App and it runs without issue.
However once I enable the access restriction by checking "Selected Networks"no matter what virtual network subnets I enter or IP Addresses I can not get the communication to work
I have entered the Outbound IP Addresses of our Consumption based Function App and also check that the additional IP Addresses from the Powershell and all have been added to the whitelist. I have also added all the CIDR IP ranges of the local Azure datacenter but again it does not work.
The problem we have is that once the access restrictions have been put into place we are unable to deploy to the Function App and the app no longer runs. Is this scenario supported and what is the mechanism for tying down access to the Storage Account so that only the Function App can utilise it.
As far as I know, you have two options to restrict access to your storage account from your function app or web app.
Whitelist the outboundIpAddresses and possibleOutboundIpAddresses of the function app in the firewall of the storage account. However, it does not work if the Azure function app and Azure storage located in the same region refer to Sam's answer.
when you hit the storage account from your function, because they are
in the same region as each other, all the traffic goes over the
internal Azure network on internal IP's, not the public IPs listed in
the web app, and so is not allowed over the firewall.
If your resources were in different regions, you could use the network section of function app to allow function app to access resources in a VNet, then enable service endpoint for Microsoft.Storage in this app integration subnet. But you need Azure Functions Premium plan referring to this tutorial: integrate Functions with an Azure virtual network.
Sometimes, the deployment order for networking is important. In this case, you will deploy the followings:
Firstly, you could deploy new VNet integration with an unused subnet. After the VNet Integration is completed and the function app is restarted, you could enable service endpoint for this subnet. In the end, you could add the subnet in the firewall of the storage account.
Note that the new version is in Preview, currently. You could also check these characteristics and get more references from this thread.
Originally I tried to restrict access from an app service to blob storage using IP addresses, however it turned out that you can only do this using a Virtual Network: Firewall access from Azure app service to blob storage
I want to be able to achieve this without setting up a point-to-site VPN. The steps I have taken to set up a virtual network in Azure are as follows:
Created Network security group "securitygroup-frontend", add custom
inbound rule called Web with Source: Service Tag, Source service tag:
Internet, Source port ranges: *, Destination : Any, Destination port
ranges: 80, 443, Protocol: Any, Action: Allow, Priority: 100
Created Virtual Network with address space 192.168.0.0/23 and subnet called frontend address range 192.168.0.0/26 with network security group: securitygroup-frontend and subnet delegation to Microsoft.Web/serverFarms and service endpoints Microsoft.Storage
Went to app service -> Networking -> Configure VNet integration ->
Add VNet preview and select the subnet you created
Went to Storage -> Firewalls and virtual Networking -> Configure VNet integration -> Select 'Selected networks' and add in the virtual network and subnet just created.
I have had to move Azure diagnostics and logs such as for key vault, service bus and sql azure to its own blob storage as these require blob storage outside of a virtual network and can't be made to work inside. The app service is in the Standard plan. The app service, blob storage and virtual network are all in the same region.
This question and answer does not provide any insights: https://social.msdn.microsoft.com/Forums/azure/en-US/9f4d8aeb-68a6-4ec1-9e11-bee2d1301792/allow-access-to-azure-storage-account-only-from-an-app-service?forum=windowsazurewebsitespreview
The above steps though block off access from the app service to blob storage and any assets within return an error: (403) Forbidden. If I remove the Virtual network from blob storage it works fine. What am I doing wrong?
Yes, you can do this using a VNet but you need to deploy the web app in a VNet with App Service Environments. You can not do this with VNet integration. Integrating Azure services to an Azure virtual network enables private access to the service from virtual machines or compute resources in the virtual network. However, web app service in a regular app service plan is multi-tenant. With ASE, you could deploy it into your VNet.
You could get more details and explanation from this similar thread. According to a comment from silent, you could also consider deploying your web app inside a container which could be deployed in a VNet with some restriction.
Update
Sometimes, the deployment order for networking is important. In your case, you enable service endpoint before VNet integration. I suggest removing NSG restriction in integrated app subnet VNet for a test. Then you could check the following steps.
Firstly, you could deploy new VNet integration with an unused subnet. After the VNet Integration is completed and the web app is restarted, you could enable service endpoint and subnet delegation for this subnet. In the end, you could add the subnet in the firewall of the storage account.
The new version is in Preview and not GA currently. It might be not all functions available. you could also check the following characteristics.
No gateway is required to use the new VNet Integration feature。
You can access resources across ExpressRoute connections without any additional configuration beyond integrating with the ExpressRoute connected VNet.
The app and the VNet must be in the same region.
The new feature requires an unused subnet in your Resource Manager VNet.
Your app must be in an Azure App Service deployment that is capable of scaling up to Premium v2.
Your App Service plan must be a Standard, Premium, or PremiumV2 plan Production workloads are not supported on the new feature while
it is in Preview
The new VNet Integration feature doesn't work for apps in an App Service Environment.
You cannot delete a VNet with an integrated app.
Route tables and global peering are not yet available with the new VNet Integration.
One address is used for each App Service plan instance. Since subnet size cannot be changed after assignment, use a subnet that can
more than cover your maximum scale size. A /27 with 32 addresses is
the recommended size as that would accommodate an App Service plan
that is scaled to 20 instances.
You can consume Service Endpoint secured resources using the new VNet Integration capability. To do so, enable service endpoints on the
subnet used for VNet Integration.