Docker: Use runtime-deps base image

Dockerfile

@@ -1,5 +1,5 @@
 # Build the runtime image
-FROM mcr.microsoft.com/dotnet/aspnet:10.0-alpine AS runtime
+FROM mcr.microsoft.com/dotnet/runtime-deps:10.0-alpine AS runtime
 
 # Add build argument for publish directory
 ARG PUBLISH_DIR

core/Azure.Mcp.Core/tests/Azure.Mcp.Core.UnitTests/Infrastructure/VersionSyncTests.cs

@@ -82,7 +82,8 @@ private static string GetDotNetRuntimeVersionFromDockerfile(string dockerfilePat
         // Look for patterns like:
         // - FROM mcr.microsoft.com/dotnet/aspnet:9.0.5-bookworm-slim
         // - FROM mcr.microsoft.com/dotnet/aspnet:10.0-alpine
-        var pattern = @"FROM\s+mcr\.microsoft\.com/dotnet/aspnet:(\d+\.\d+(\.\d+)?)";
+        // - FROM mcr.microsoft.com/dotnet/runtime-deps:10.0-alpine
+        var pattern = @"FROM\s+mcr\.microsoft\.com/dotnet/(?:aspnet|runtime-deps):(\d+\.\d+(\.\d+)?)";
         var match = Regex.Match(dockerfileContent, pattern);
 
         if (match.Success)

servers/Azure.Mcp.Server/CHANGELOG.md

@@ -16,7 +16,7 @@ The Azure MCP Server updates automatically by default whenever a new release com
 
 ### Features Added
 
-- Enabled trimmed binary for Docker and HTTP transport support for all distributions. [[#1760](https://github.com/microsoft/mcp/pull/1760)]
+- Enabled trimmed binary for Docker and HTTP transport support for all distributions, reducing the Azure MCP Docker image size by ~40% (arm64: 1.21 GB to ~648 MB, amd64: 1.31 GB to ~784 MB). [[#1760](https://github.com/microsoft/mcp/pull/1760)]
 
 ### Other Changes
 

servers/Azure.Mcp.Server/changelog-entries/1771625444448.yaml

@@ -0,0 +1,3 @@
+changes:
+  - section: "Other Changes"
+    description: "Switch Docker base image to runtime-deps:10.0-alpine. Since the server binary is self-contained, the full ASP.NET runtime base is unnecessary. Expected ~20-25% image size reduction (for e.g. azure-mcp images arm64: 648MB to ~482MB, amd64: 784MB to ~624MB)."