Developer Briefing — October 1, 2024

Executive briefing: Microsoft’s product lifecycle bulletin sets 12 November 2024 as the end of support for .NET 6 LTS. No further security or servicing patches will land after the November Patch Tuesday. Production APIs, Azure Functions, Kubernetes workloads, and desktop apps should target .NET 8 LTS now; teams that rely on .NET 7-only libraries can dual-target 7 and 8 until the March 2025 servicing train stabilises.

Risk timeline

Now–mid October: Complete compatibility scans with dotnet workload list, dotnet list package --vulnerable, and container base-image checks to flag .NET 6 bindings.
Late October 2024: Freeze new .NET 6 deployments; land migration pull requests to .NET 8 LTS (or .NET 7 for dual-targeting) so November security patch validation runs on supported runtimes.
12 November 2024: Final .NET 6 patch train ships; Azure App Service and Functions images with .NET 6 move to unpatched status, triggering regulatory patch-SLA exceptions.
Q1 2025: Retire remaining .NET 6 containers and agents; update CI runners (GitHub Actions, Azure Pipelines) to .NET 8 hosted images.

Migration moves

Target frameworks: Switch Tfms to net8.0 (or multi-target net7.0;net8.0) and enable container build images based on mcr.microsoft.com/dotnet/aspnet:8.0.
Dependency validation: Run dotnet list package --outdated and upgrade EF Core, ASP.NET middleware, and Azure SDK packages to 8.x lines that declare support for .NET 8.
Performance checks: Enable DOTNET_TieredPGO=1 and crossgen2 precompilation in staging to validate startup and memory improvements before production cutovers.
Platform readiness: Align observability agents (App Insights, OpenTelemetry exporters) and security scanners that embed .NET 6 runtime components with .NET 8-compatible releases.

Compliance guardrails

Map patch SLAs to the November 2024 cutoff so audit teams can document exceptions for any .NET 6 workloads that cannot be retired by Patch Tuesday.
Document regression testing across API surface changes (minimal APIs, Kestrel defaults, gRPC) and capture operational runbooks for ARM64 container images where applicable.
Update SBOM generation (e.g., dotnet publish /p:GenerateDocumentationFile=true with CycloneDX) to record the runtime changeover for downstream consumers.

Sources

Zeph Tech offers .NET 8 upgrade playbooks covering container base images, dependency uplift, and regression testing for cloud and on-prem deployments.