Action required: Debian 11 ("Bullseye") Upcoming EOL (July 2024)

[richlander]

Debian 11 ("Bullseye") is expected to go End-of Life (EOL) later this month. We use Debian 11 as the base image for our our "default" .NET 6 container images, for example using the 6.0 tag. We will continue this practice until .NET 6 EOL. We recommend that .NET 6 users move to Debian 12 or to our Alpine or Ubuntu images.

We started publishing Debian 12 ("Bookworm") images for .NET 6 last year (due to OpenSSL support). You can start using those images, today.

.NET 6 + Debian 12 ("Bookworm") tags have the following form:

• 6.0-bookworm-slim
• 6.0-bookworm-slim-amd64
• 6.0-bookworm-slim-arm64v8
• 6.0-bookworm-slim-arm32v7

Alternatively, you can upgrade your app to .NET 8. It is based on Debian 12 ("Bookworm"), which was released last year. That's by far the best option since .NET 6 will go EOL in November of this year.

The existing 6.0 tags will continue to use Debian 11. We will not be automatically upgrading them to Debian 12 since that would be a breaking change and would be certain to break some apps. Users will need to opt-in to using different tag to adopt Debian 12 (or some other distro).

We are sorry for this inconvenience.

Details

For several years, Debian and .NET LTS releases have been nearly aligned with Debian releasing first, 4-6 months ahead of .NET. We've been adopting the new Debian version for our container images with each new .NET LTS release. That has worked well. Our default images have been based on Debian since .NET Core 1.0.

.NET 6 shipped in November 2021, a few months after Debian 11. We made the natural choice to base the default .NET 6 container images on Debian 11.

Debian and .NET have a similar lifecycle, lasting three years for mainline support. That means that Debian goes EOL while .NET is still in support. Fortunately, Debian goes into an LTS phase after EOL, but that effort is handled by community volunteers, not the Debian Security team. That's good, but not ideal.

We will run into this same problem again with Debian 12 ("Bookworm") for the last 6 months of .NET 8 support. That's not ideal. To remedy the problem, we're proposing to switch the default .NET tags to Ubuntu, starting with .NET 10, per #5709.