Chapter 3. Known issues for containers

The dnf command is not available

To reduce image size, the .NET 10.0 container images are based on the ubi-minimal base image instead of the standard ubi image. The ubi-minimal image provides microdnf as its package manager, not dnf.

If your Dockerfiles or Containerfiles use the dnf command, you must update them to use microdnf instead.

For more information, see the microdnf(8) man page.

UBI-prefixed repositories no longer use .NET version tags

The UBI-prefixed repositories (for example, ubi9/dotnet-100 and ubi9/dotnet-100-runtime) no longer include tags for the .NET version.

Following the standard for UBI repositories, tagging is now based on the RHEL version. To get the latest version, either omit the tag (which defaults to latest) or explicitly use the latest tag.

ASP.NET Core runtime is in a separate image

Starting with .NET 10.0, the .NET runtime images (for example, registry.access.redhat.com/ubi9/dotnet-100-runtime) no longer include the ASP.NET Core runtime.

If your application requires the ASP.NET Core runtime, you must use the new ASP.NET Core runtime image (for example, registry.access.redhat.com/ubi9/dotnet-100-aspnet).

ASP.NET Core runtime is in a separate ImageStream

Starting with .NET 10.0, the s2i-dotnetcore OpenShift dotnet-runtime ImageStream no longer includes the ASP.NET Core runtime.

If your application requires the ASP.NET Core runtime, you must use the new dotnet-aspnet ImageStream instead.

The default WORKDIR is / instead of /opt/app-root/app

Starting with .NET 10.0, the .NET runtime and ASP.NET Core container images use / as the default working directory. This change aligns Red Hat images with the default used by other vendors.

The WORKDIR instruction sets the working directory for any subsequent RUN, CMD, ENTRYPOINT, COPY, and ADD instructions. If your Dockerfiles or Containerfiles rely on the previous default working directory, you must add an explicit WORKDIR directive. For example:

WORKDIR /app