Getting started with .NET on OpenShift Container Platform
Installing and running .NET 8.0 on OpenShift Container Platform
Abstract
Making open source more inclusive
Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright’s message.
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Chapter 1. Overview
NET images are added to OpenShift by importing imagestream definitions from s2i-dotnetcore.
The imagestream definitions include the dotnet
imagestream which contains sdk images for different supported versions of .NET. Life Cycle and Support Policies for the .NET Program provides an up-to-date overview of supported versions.
Version | Tag | Alias |
---|---|---|
.NET 6.0 | dotnet:6.0-ubi8 | dotnet:6.0 |
.NET 7.0 | dotnet:7.0-ubi8 | dotnet:7.0 |
.NET 8.0 | dotnet:8.0-ubi8 | dotnet:8.0 |
The sdk images have corresponding runtime images which are defined under the dotnet-runtime
imagestream.
The container images work across different versions of Red Hat Enterprise Linux and OpenShift. The UBI-8 based images (suffix -ubi8) are hosted on the registry.access.redhat.com
and do not require authentication.
Chapter 2. Installing .NET image streams
To install .NET image streams, use image stream definitions from s2i-dotnetcore with the OpenShift Client (oc
) binary. Image streams can be installed from Linux, Mac, and Windows.
You can define .NET image streams in the global openshift
namespace or locally in a project namespace. Sufficient permissions are required to update the openshift
namespace definitions.
Procedure
Install (or update) the image streams:
$ oc apply [-n namespace] -f https://raw.githubusercontent.com/redhat-developer/s2i-dotnetcore/main/dotnet_imagestreams.json
Chapter 3. Deploying applications with OpenShift Client
You can use OpenShift Client (oc) for application deployment. You can deploy applications from source or from binary artifacts.
3.1. Deploying applications from source using oc
The following example demonstrates how to deploy the example-app application using oc
, which is in the app
folder on the dotnet-8.0
branch of the redhat-developer/s2i-dotnetcore-ex
GitHub repository:
Procedure
Create a new OpenShift project:
$ oc new-project sample-project
Add the ASP.NET Core application:
$ oc new-app --name=example-app 'dotnet:8.0-ubi8~https://github.com/redhat-developer/s2i-dotnetcore-ex#dotnet-8.0' --build-env DOTNET_STARTUP_PROJECT=app
Track the progress of the build:
$ oc logs -f bc/example-app
View the deployed application once the build is finished:
$ oc logs -f dc/example-app
The application is now accessible within the project.
Optional: Make the project accessible externally:
$ oc expose svc/example-app
Obtain the shareable URL:
$ oc get routes
3.2. Deploying applications from binary artifacts using oc
You can use .NET Source-to-Image (S2I) builder image to build applications using binary artifacts that you provide.
Prerequisites
Published application.
For more information, see
Procedure
Create a new binary build:
$ oc new-build --name=my-web-app dotnet:8.0-ubi8 --binary=true
Start the build and specify the path to the binary artifacts on your local machine:
$ oc start-build my-web-app --from-dir=bin/Release/net8.0/publish
Create a new application:
$ oc new-app my-web-app
Chapter 4. Environment variables for .NET 8.0
The .NET images support several environment variables to control the build behavior of your .NET application. You can set these variables as part of the build configuration, or add them to the .s2i/environment
file in the application source code repository.
Variable Name | Description | Default |
---|---|---|
DOTNET_STARTUP_PROJECT |
Selects the project to run. This must be a project file (for example, |
|
DOTNET_ASSEMBLY_NAME |
Selects the assembly to run. This must not include the |
The name of the |
DOTNET_PUBLISH_READYTORUN |
When set to |
|
DOTNET_RESTORE_SOURCES |
Specifies the space-separated list of NuGet package sources used during the restore operation. This overrides all of the sources specified in the | |
DOTNET_RESTORE_CONFIGFILE |
Specifies a | |
DOTNET_TOOLS |
Specifies a list of .NET tools to install before building the app. It is possible to install a specific version by post pending the package name with | |
DOTNET_NPM_TOOLS | Specifies a list of NPM packages to install before building the application. | |
DOTNET_TEST_PROJECTS |
Specifies the list of test projects to test. This must be project files or folders containing a single project file. | |
DOTNET_CONFIGURATION |
Runs the application in Debug or Release mode. This value should be either |
|
DOTNET_VERBOSITY |
Specifies the verbosity of the | |
HTTP_PROXY, HTTPS_PROXY | Configures the HTTP or HTTPS proxy used when building and running the application, respectively. | |
DOTNET_RM_SRC |
When set to | |
DOTNET_SSL_DIRS |
Deprecated: Use | |
SSL_CERT_DIR |
Specifies a list of folders or files with additional SSL certificates to trust. The certificates are trusted by each process that runs during the build and all processes that run in the image after the build (including the application that was built). The items can be absolute paths (starting with | |
NPM_MIRROR | Uses a custom NPM registry mirror to download packages during the build process. | |
ASPNETCORE_URLS |
This variable is set to |
|
DOTNET_RESTORE_DISABLE_PARALLEL |
When set to |
|
DOTNET_INCREMENTAL |
When set to |
|
DOTNET_PACK |
When set to |
Chapter 5. Creating sample applications with .NET 8.0
5.1. Creating the MVC sample application
s2i-dotnetcore-ex
is the default Model, View, Controller (MVC) template application for .NET.
This application is used as the example application by the .NET S2I image and can be created directly from the OpenShift UI using the Try Example link.
The application can also be created with the OpenShift client binary (oc
).
Procedure
To create the sample application using oc
:
Add the .NET application:
$ oc new-app dotnet:8.0-ubi8~https://github.com/redhat-developer/s2i-dotnetcore-ex#dotnet-8.0 --context-dir=app
Make the application accessible externally:
$ oc expose service s2i-dotnetcore-ex
Obtain the sharable URL:
$ oc get route s2i-dotnetcore-ex
Additional resources
5.2. Creating the CRUD sample application
s2i-dotnetcore-persistent-ex
is a simple Create, Read, Update, Delete (CRUD) .NET web application that stores data in a PostgreSQL database.
Procedure
To create the sample application using oc
:
Add the database:
$ oc new-app postgresql-ephemeral
Add the .NET application:
$ oc new-app dotnet:8.0-ubi8~https://github.com/redhat-developer/s2i-dotnetcore-persistent-ex#dotnet-8.0 --context-dir app
Add environment variables from the
postgresql
secret and database service name environment variable:$ oc set env dc/s2i-dotnetcore-persistent-ex --from=secret/postgresql -e database-service=postgresql
Make the application accessible externally:
$ oc expose service s2i-dotnetcore-persistent-ex
Obtain the sharable URL:
$ oc get route s2i-dotnetcore-persistent-ex
Additional resources