I have azure app service which runs .net core web api. This api access several external API s to get data and those external services has to whitelist the outbound ip addresses of my app service.
Azure app service has several outbound ip addresses and it can be change when upgrade/downgrade app service or when make internal changes like changing app service plan or resource group.
Is there any solution in azure to setup this app service behind a forward proxy ?, so i can share the IP of the forward proxy to external parties.
I think the best way would be to add all App services under a virtual network and create a Virtual Network Gateway to all outbound connections.
This would potentially need below azure services to be created:
- Virtual network
- Subnet
- Virtual Network gateway
- Routing tables (to route traffic via Gateway)
A better way would be sharing a domain name rather than IP address. Here's how to configure it directly in the Azure Portal:
https://learn.microsoft.com/en-us/azure/app-service/app-service-web-tutorial-custom-domain
You can also add an API Management in front of your web app and use it as API gateway and also apply policies on it.
https://learn.microsoft.com/en-us/azure/api-management/configure-custom-domain
Related
I deploy my web application to an App Service instance on Premium tier. My web application makes outbound requests to external resources on the Internet.
In order to secure the connection with one of these external resources so I can reach it with a private IP address, my plan is to create a Site-to-Site VPN from Azure to Oracle Cloud Infrastructure (where the external resource resides). Then, I plan to use the VNET Integration for outbound traffic and connect my App Service to my VPN.
My question is - will the web application still be able to reach the other external resources on the Internet with their public IPs? I believe the answer is related to routing tables but I can't wrap my mind around it.
Just because you integrate a Regional VNet (I'm assuming) doesn't mean the app service won't be able to make outbound connections. Pretty much like
When you integrate your app service with your VNet that has the site-to-site VPN, traffic from your app service will traverse the Azure network rather than going out to internet, assuming your app service is using an RFC1918 address for your infrastructure. If you want to secure the traffic even further, then your app service would need to be hosted inside an App Service Environment
I want to restrict access to my Azure Container App with an Api Management in Azure.
I successfully linked the Api Management with the Container App and I have activated a Subscription with an Api Key that will prevent public access over the Api Management Service Url. The problem, however, is that the Container App can still be accessed over the public Url of the Container App.
There is still the option to set the Ingress Traffic in the Container App to Limited to Container Apps Environment but then the Api Management will not have access to the Container App as well.
What is the correct way to properly secure the Container App behind an Api Management Service?
For Azure Container Instances, you don't have the option to configure IP restrictions similar to Azure App Services. Instead you will have to first create a virtual network and configure a Network Security Group to Deny all traffic from the internet and allow only from APIM, and then deploy your Azure Container Instance to this virtual network.
See here for deploying an azure container instance to a virtual network : https://learn.microsoft.com/en-us/azure/container-instances/container-instances-vnet
For configuring network security groups in your virtual network see : https://learn.microsoft.com/en-us/azure/virtual-network/manage-network-security-group#work-with-security-rules
You app service is still accessible over the public internet because you haven't configured Access Restrictions in your App Service's Network.
What you need to do is go to your App service. Then select Networking from the left menu and Turn on Access Restrictions for inbound traffic.
Create an access restriction rule to deny from the internet.
Next create a second acccess rule to allow access from the APIM. Ensure the priority on this one is higher.
Read the Microsoft Docs on how to set app service IP restrictions here : https://learn.microsoft.com/en-us/azure/app-service/app-service-ip-restrictions
Assuming your API management service has a static IP (not a consumption plan), you would need to use you own VNET:
Networking architecture in Azure Container Apps
Then using NSG, you could add an inbound rule to only allow traffic from the APIM service IP on HTTPS (TCP 443).
Azure container apps do now seem to have the ability to restrict inbound ip addresses
https://azure.microsoft.com/en-gb/updates/public-preview-inbound-ip-restrictions-support-in-azure-container-apps/
We have are looking at a similar architecture with a similar dilemma. Everything we have is secured with Azure b2c but if I want to make an internal container/microservice accessible to Azure Api Management I think I'd have to drop b2c (api management has no UI to log into b2c) and make it publicly accessible via the Ingress. If the inbound ip addresses are restricted to api management maybe that is ok. It does worry me that ip addresses can be spoofed although you'd hope Microsoft have thought of that.
Another alternative which I've not investigated but which does work for Azure functions is managed identities. This might not work at all with container apps though
https://www.svenmalvik.com/azure-apim-function-msi/
First, I think that it is good to explain networking architecture in Azure Container Apps.
Azure Container Apps run in the context of an environment, which is supported by a virtual network (VNET). When you create an environment, you can provide a custom VNET, otherwise a VNET is automatically generated for you.
There are two ways to deploy Container Apps environments:
External - Container Apps environments deployed as external resources are available for public requests. External environments are deployed with a virtual IP on an external, public facing IP address.
Internal - When set to internal, the environment has no public endpoint. Internal environments are deployed with a virtual IP (VIP) mapped to an internal IP address. The internal endpoint is an Azure internal load balancer (ILB) and IP addresses are issued from the custom VNET's list of private IP addresses.
I attach the image from Azure portal to show above two options:
Now going further, if you want your container app to restrict all outside access, create an internal Container Apps environment.
Now when it comes to deployment of the Container Apps to the Container Apps Environment, accessibility level you selected for the environment will impact the available ingress options for your container app deployments.
If you are deploying to an external environment, you have two options for configuring ingress traffic to your container app:
Limited to Container Apps Environment - to allow only traffic from other container apps deployed within the shared Container Apps environment.
Accepting traffic from anywhere - to allow the application to be accessible from the public internet.
If you are deploying to an internal environment, you also have two options for configuring ingress traffic to your container app:
Limited to Container Apps Environment - to allow only traffic from other container apps deployed within the shared Container Apps environment.
Limited to vNET (Virtual Network) - to allow traffic from the VNET to make container app to be accessible from other Azure resources or applications within the virtual network or connected to the virtual network through Peering or some type of VPN connectivity
Now in you case, what you are looking for is the architecture where you enable access to Azure Container Apps only through the Azure API Management. In this case you have to deploy Azure Container Apps Environment with Internal mode and set ingress traffic to Limited to VNet (Virtual Network).
I assume that Azure API Management can be accessible from the Internet. In this case you have to deploy Azure API Management inside an Azure Virtual Network. There are two possible modes: internal, and external. In you scenario, you can use external mode. More details can be found here. When API Management instance in the external mode, the developer portal, API gateway, and other API Management endpoints are accessible from the public internet, and backend services are located in the Azure Virtual Network.
Here I also attach the solution architecture to show how all these components are connected together. I also have Azure Front Door here but API Management is deployed with external mode. Please remember that you will also need private DNS Zone for your Azure Container Apps Environment domain, to make it possible to refer to specific APIs from the Azure API Management using URLs, example:
https://ca-tmf-mip-vc-api--v-01.blacklacier-cf61414b.westeurope.azurecontainerapps.io
Helpful links:
Repo with Bicep files to deploy Azure Container App with internal mode
Azure Container Apps Virtual Network Integration
I have a configuration in Azure with a Virtual Network and 2 subnets.
In 1 subnet I have an App Service Environment v3 + App Service Plan + Logic App Standard. I have a workflow with an HTTP Trigger.
In the other subnet, I have an API Management instance, and I need to expose my Http triggered workflow as an API in APIM.
The DNS of the Virtual Network is hosted internally (on-premises) and not managed by Azure. There is no conditional forwarding setup for the moment.
Because of this, the URL of the workflow is something like ..appserviceenvironment.net/.
The DNS name cannot be resolved and I want to know what is the solution I can put in place to make it work? Do I need to create a private DNS zone for the ".appserviceenvironment.net" and add manually the private IP of the app service environment?
• I would suggest you to please refer to the github link below for more information and step by step details regarding the connectivity to a virtual network in an internal mode using the Azure API management: -
https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/api-management/api-management-using-with-internal-vnet.md
It states that API gateway, developer portal, direct management and Git are the only endpoints that are accessible from the virtual network that is configured in the internal mode for API Management instance. Also, the service endpoints will remain inaccessible until you configure DNS for your virtual networks.
Also, using API Management in internal mode will expose your cloud-based APIs and on-premises APIs through a common gateway in hybrid cloud scenarios. And to configure the common gateway, you will have to provision a private DNS zone and link it into your virtual network through a hostname which is configured on the service endpoints, one of which when using the private DNS zone is the API gateway with which you want to have a workflow with an HTTP trigger.
Please go through the link below for configuring the routing details related to API Management Instance in the virtual network: -
https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/api-management/api-management-using-with-internal-vnet.md#routing
I have 2 app service plans in the same Azure region running 1 app each - web frontend on one, API on the other.
I want to use access restrictions on the API to only allow access from the front end app.
I set access restriction rules using all the outgoing IP addresses associated with the frontend app (I note that these are exactly the same as the outgoing IP addresses on the API app as well) however when the frontend app tries to contact the API I get an error:
403 forbidden 'The web app you have attempted to reach has blocked your access.'
The 2 apps can communicate as normal when the access restrictions are removed.
I turned on diagnostic settings and ran a query on IP blocking by the app.
Turns out that the FE app is using an IPv6 address instead of the v4 addresses listed in the app properties.
This is because the app has a vnet integration set up connecting to a Subnet delegated to Webservice/serverfarm.
Azure does not make it obvious that using delegated subnets forces an integrated app to use IPv6 and there does not appear to be a way to discover what v6 addresses may be in use. MS forum response suggests any firewall rule for a web app attached to a delegated subnet should allow ALL IPv6 addresses (!!) as a way of working around the problem.
https://learn.microsoft.com/en-us/answers/questions/493483/why-is-my-azure-web-app-showing-an-ipv6-outbound-i.html
You can control the IP address of outbound traffic from your FE web app by using regional VNet integration together with a virtual network NAT gateway to direct traffic through a static public IP address. Regional VNet integration is available on Standard, Premium, PremiumV2 and PremiumV3 App Service plans. To learn more about this setup, see NAT gateway integration.
Once you FE web app has a static IP you can use that on the API web app restriction in an ALLOW rule.
If your requirement fits, you may also leverage Service Endpoints.
With service endpoints,to ensure inbound traffic to your API app comes only from the subnet used by your front-end web app.
With this route, you need to use VNet Integration with your front end app and service endpoints with your API app. Set service endpoints on the integration subnet used by your Front End application. This solution is fast to set up and easy as well.
-This feature works together with IP access restrictions. Service endpoints aren't compatible with remote debugging. There are some considerations you need to make, you may take a look at them here and also other combination of networking features available on App Service and related scenarios.
As a side note:
-IP-based access restriction rules only handle virtual network address ranges when your app is in an App Service Environment. If your app is in the multitenant service, you need to use service endpoints to restrict traffic to select subnets in your virtual network.
-On App Service, you could have those two separate apps in the same App Service Plan (ASP), since you pay only for ASP, saving costs.
So, you can continue to add apps to an existing plan as long as the plan has enough resources to handle the load. The apps in the same App Service plan all share the same compute resource.
We have an Azure Web App and Azure VPN, we've locked down the web app so it's accessible internally only by granting/restricting access via IP addresses (via Access Restrictions page). However users over our VPN are not able to access the web app - when they connect over VPN, the user's external IP address is not from our internal network. We do not want to whitelist everyone's IP address.
If we had the internal IP address of the web app, we have a few options we could try, but we assume this is not available to us.
How would we allow access to a web app for users over a VPN?
Is this something API Management would solve?
If you don't want to whitelist everyone's IP address. You could involve front-ending the Web App with an Azure Application Gateway and restricting access to the Web App such that only connections from the Gateway are allowed.
Azure Application Gateway is a web traffic load balancer. It has a public or a private frontend or both backends, it must deploy in a dedicated subnet. The subnet also supports to restrict the network inbound and outbound traffic with NSG. In this case, you can deploy a private app GW, then the users over VPN will send the HTTP/HTTPS requests to the APP GW frontend, the APP GW receives the requests via Listener and routes the traffic to the appropriate backends based on the routing rules. An application gateway can communicate with to on-premises servers when they're connected by Azure ExpressRoute or VPN tunnels if traffic is allowed. See supported backend pools and how an application gateway works.
You could get more references from the third way in this blog.