The .NET runtime is the software stack responsible for installing your application code and dependencies, and then running that application in the flexible environment.
.NET versions
.NET 8 is built using buildpacks. For the full list of supported .NET versions, and their corresponding Ubuntu version, see the Runtime support schedule.
To use a supported .NET version, you must:
Update your project file with the .NET version you want to use.
<Project Sdk="Microsoft.NET.Sdk.Web"> <PropertyGroup> <TargetFramework>net8.0</TargetFramework> <Nullable>enable</Nullable> <ImplicitUsings>enable</ImplicitUsings> </PropertyGroup> <ItemGroup> <None Update="app.yaml"> <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory> </None> </ItemGroup> </Project>
For more information see Migrate from ASP.NET Core 3.1 to 6.0.
Install gcloud CLI version 420.0.0 or later. You can update your CLI tooling by running the gcloud components update command. To view your installed version, you can run the gcloud version command.
Specify the
operating_system
setting in yourapp.yaml
file:runtime: aspnetcore env: flex runtime_config: operating_system: "ubuntu22"
Optionally, you can specify a runtime version by including the
runtime_version
setting in yourapp.yaml
file. By default, App Engine uses the latest available LTS .NET version if theruntime_version
setting is not specified. For example, theapp.yaml
file looks as follows when specifying .NET 8 on Ubuntu 22:runtime: aspnetcore env: flex runtime_config: runtime_version: "8" operating_system: "ubuntu22"
Previous runtime versions
To target a specific .NET SDK version, update your project file. For more information, see Migrate from ASP.NET Core 3.1 to 6.0.
If you want to use GKE or other Docker hosts, you need to create a Dockerfile that copies your application code and installs dependencies. For more information, see Custom Runtimes.
To deploy your .NET app, run the following commands from the root directory where your app resides:
dotnet restore
dotnet publish -c Release
gcloud app deploy
Support for other .NET runtimes
If you need to use a .NET version that isn't supported, you can create a custom runtime and select a valid base image with the .NET version you need.
For Google-supplied base images or Docker .NET base images, see Building custom runtimes.
HTTPS and forwarding proxies
App Engine terminates the HTTPS connection at the load balancer and forwards the
request to your application. Applications can examine the X-Forwarded-Proto
to
observe whether the original protocol was HTTP or HTTPS.
Some applications also need to ascertain the user's IP address. This is
available in the standard X-Forwarded-For
header.
Extending the runtime
The flexible environment .NET runtime can be used to create a custom runtime.
Custom runtimes are configured via a Dockerfile
.
You can customize the Dockerfile
and .dockerignore
as desired. Finally,
you will need to specify runtime: custom
instead of runtime: aspnetcore
in
app.yaml
. See
Customizing the .NET Runtime
for more information.
Environment variables
The following environment variables are set by the runtime environment:
Environment variable | Description |
---|---|
GAE_INSTANCE |
The name of the current instance. |
GAE_MEMORY_MB |
The amount of memory available to the application process. |
GAE_SERVICE |
The service name specified in your application's app.yaml
file, or if no service name is specified, it is set to default . |
GAE_VERSION |
The version label of the current application. |
GOOGLE_CLOUD_PROJECT |
The Project ID associated with your application, which is visible in the Google Cloud console |
PORT |
The port that will receive HTTP requests. |
You can set additional configuration variables with appsettings.json
.
Metadata server
Each instance of your application can use the Compute Engine metadata server to query information about the instance, including its host name, external IP address, instance ID, custom metadata, and service account information. App Engine does not allow you to set custom metadata for each instance, but you can set project-wide custom metadata and read it from your App Engine and Compute Engine instances.
This example function uses the metadata server to get the external IP address of the instance: