I'm trying to configure an app service such that it has a private link setup into our VPN enabled vnet but also allow public access (e.g. to allow front door and our devops agents access).
The docs (https://learn.microsoft.com/en-gb/azure/app-service/networking/private-endpoint) note that "by default" public access is diabled, to me that sounds like it is possible to not have the default, is that actually possible?
I'd rather not route everything through our vnet (using hub and spoke design) because to my mind that adds a single point of failure we don't need, e.g. having front door connect to the app service over the MS backbone means it isn't reliant on my vnet infrastructure. But the vpn access is useful for internal access direct to the app service.
I also asked this on the MS forums and with some help came to what i think is an acceptable answer: https://learn.microsoft.com/en-us/answers/questions/968600/app-service-using-private-link-but-still-need-publ.html
Related
can anyone explain difference between Azure Application Gateway, Virtual Network Gateway, Virtual WAN, ExpressRoute, Arc and Private Link, please?
It seems to me all services are pretty similar helping with connecting either on-prem to Azure, in-Azure to in-Azure or public to Azure.
They're similar in that they all involve network traffic, but that's pretty much where the similarities end.
Application Gateway is a Layer 7 load balancing service with advanced features like SSL termination. It's used to route client requests to your applications.
Virtual Network Gateway is a VPN gateway for point-to-site (user) and site-to-site (office/datacenter) VPN connections to your own Azure VNETs. This would, for example, allow you to RDP into Azure VMs from your on-prem office using their private IPs.
ExpressRoute is similar to site-to-site, however it doesn't use IpSec tunnels, it's a dedicated, unencrypted connection from your location directly into Microsoft's backbone. (i.e. you don't traverse the public internet). There's no encryption and the connection is faster. This is a service you need to work with a 3rd party internet provider to implement.
Virtual WAN is more like a networking hub where there would be many site-to-site, point-to-site, ExpressRoute, etc... connections spanning a wide area (as the name implies). This would be for large enterpise organizations with many on-prem locations.
Arc is a means of adding your on-prem resources into Azure for management. e.g. you have a physical server somewhere and you want to manage it though ARM/portal.
Azure Private Link is a feature of many Azure services (storage, SQL PaaS, etc..) which allows you to create a private DNS record and assign a private IP address on your internal VNETs. This is used when you want to disable all public network access to a resource and only allow access from within your own VNET.
I have barely scratched the surface of the differences here, but suffice it to say, there are many differences. From this page, you can type the service name into the search and get more specific details on the offering. Hope this helps.
https://learn.microsoft.com/en-us/search/?terms=networking%20in%20azure
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
We have three App Services in Azure (API1, API2, API3).
API2 is getting data from CosmosDB.
API3 is getting data from other CosmosDB.
Main API1 calls API2 to get some data. Then using this data calls API3.
We have poor performance of API1 and we are trying to figure out why. We noticed that there are too many connections in metrics. Also we have issue with SNAT ports.
We tried to setup these APIs to the same VNet but it doesn't help and we are not sure how to set up it correctly.
Do you have any idea what we should setup?
UPDATE:
Seems like VNet helped us with SNAT ports issue but performance of API was still very poor.
What really helped us was change from Windows to Linux. When all APIs runs on the Linux servers we don't see any connections anymore.
Not sure what's specific configurations about three APIs on your side. If you want to use IP from Vnet instead of an external one, you can use a separate environment ASE.
Alternatively, you can use a private link to the app service. By using Private Endpoint, you can connect privately to your web app. Read Connect privately to a web app by using Azure Private Endpoint (Preview).
Today, you can secure this connection using VNet service endpoints
which keep the traffic within the Microsoft backbone network and allow
the PaaS resource to be locked down to just your VNet. However, the
PaaS endpoint is still served over a public IP address and therefore
not reachable from on-premises through Azure ExpressRoute private
peering or VPN gateway. With today’s announcement of Azure Private
Link, you can simply create a private endpoint in your VNet and map it
to your PaaS resource (Your Azure Storage account blob or SQL Database
server). These resources are then accessible over a private IP address
in your VNet, enabling connectivity from on-premises through Azure
ExpressRoute private peering and/or VPN gateway and keep the network
configuration simple by not opening it up to public IP addresses.
For more information, you could read here.
I need to configure Azure SQL Database firewall settings so that it can only be accessed by my Azure Function app. The problem is I'm running the app in a consumption plan, and as far as I know, the outbound IP address(es) can change even when I don't take any actions.
Is there a way to whitelist the app so that I protect the database from unwanted connections?
I thought of whitelisting by Azure region since everything is hosted in the same region, but then how do I guard against other apps in the same region? That's why I'm thinking of using specific IP addresses. My only concern with this approach is, I don't know if other function apps can share the same outbound IP addresses as my own.
P.S. Currently, my firewall settings deny public network access and allow Azure services to connect only.
There are several ways to achieve this.
You may want to integrate VNet or get static IP addresses for your Azure Functions
Image from: https://learn.microsoft.com/en-us/azure/azure-functions/functions-networking-options
However, what I've seen from your comments you don't want to go the premium plan.
The last thing I can suggest you implement Managed Service Identity.
The idea behind this, instead of connecting the database with connection string, you connect to the database with the access token that you granted. You can't get the access token if you are not in the same Identity.
This tutorial explains the general idea with App Service:
https://learn.microsoft.com/en-us/azure/app-service/app-service-web-tutorial-connect-msi
and this tutorial pretty much covers what do you really want to achieve.
https://www.azurecorner.com/using-managed-service-identity-in-azure-functions-to-access-azure-sql-database/
Good luck!
I had the same issue but managed identity didn't make much difference.
In the firewall setting for the SQL server there is an option to allow azure resources to access the server. For me this was set to no, but needed to be set to yes.
One thing you can do is assign a managed identity to your function. It will retrieve a token from Azure AD, and it will be used to connect to Azure SQL:
if (accessToken != null) {
string connectionString = "Data Source=<AZURE-SQL-SERVERNAME>; Initial Catalog=<DATABASE>;";
SqlConnection conn = new SqlConnection(connectionString);
conn.AccessToken = accessToken;
conn.Open();
}
https://learn.microsoft.com/en-us/azure/active-directory/managed-identities-azure-resources/tutorial-windows-vm-access-sql
You can do this by assigning a static IP to the function app and whitelist at the SQL Server -INbound Networking side and Deny all requests. However you have to change the consumption plan to Appservice to assign a static IP.
https://learn.microsoft.com/en-us/azure/azure-functions/ip-addresses#dedicated-ip-addresses
Also, you can try creating a Vnet peering for those services and block other requests.
I can't find where i got the answer (so not my answer but sharing it here), your Azure Functions have a list of outboundIpAddresses and possibleoutboundIpAddresses that you can add to your Azure SQL firewall rules (mine had about 10).
You can find them by...
Go to https://resources.azure.com
Expand Subscriptions -> [Expand your Subscription] -> Providers -> Microsoft.Web -> Sites
Find your Azure Function Site in the JSON, and locate the outboundIpAddresses and possibleoutboundIpAddresses, these will contain a list of IP addresses.
Add all of them to your SQL server's firewall.
While I'm not positive if these will ever change, so far they haven't for me and the person who originally posted this solution also noted that they haven't run into issues with this.
Virtual networks do not work on Azure the same way as they work on premises
If you create a vnet, add your Azure function in a subnet and in sql server you allow this subnet to access it will unfortunately not work.
If it is ok for you to allow "public access" and/or "azure resources access" then things are simple. You log in with sql credentials and you have access.
If you block public access I am not sure that your resources would be able to access your database, because all your connection go to SQL server from the internet not from your internal network.
Solution that worked for me is
Create a vnet
Create a private endpoint for Sql server in this vnet (custom DNS records were created by the IT-OPS people).
Azure function uses a subnet of this vnet.
Now, you can close public and azure resources access in your database.
All your calls will go through your virtual network (not through the internet anymore) and only applications that use a subnet of this vnet would be able to connect to the database.
Is it possible to use an Azure virtual machine that's setup as a domain controller to manage virtual machines hosted on other Azure subscriptions?
Personally I have never tried this before, but do not immediately see an issue with it.
I assume your Domain Controller is deployed using Microsoft's guidelines including assigning a static IP address?
With the ability to connect one VNet to another VNet (See: https://azure.microsoft.com/en-us/documentation/articles/virtual-networks-configure-vnet-to-vnet-connection/) you can create the required network connectivity.
What you probably need to do is use your own DNS server for name resolution (See: https://azure.microsoft.com/en-us/documentation/articles/virtual-networks-name-resolution-for-vms-and-role-instances/) in all connected VNets. I would recommend running DNS on your Domain Controller.
One thing to consider however is the generated traffic for authentication and name resolution. Do know that Azure is charging for traffic traversing from one Azure region to another.
Hope this helps you moving forward.
in this scenario is it required to create DNS server per subscription or one DNS server is enough for multiple subscription.