docs(dhi): add .NET and Java migration examples

content/manuals/dhi/migration/examples/_index.md

@@ -17,6 +17,14 @@ params:
       description: Learn how to migrate Node.js applications to Docker Hardened Images with practical examples and best practices.
       icon: code-bracket
       link: /dhi/migration/examples/node/
+    - title: .NET
+      description: Learn how to migrate .NET applications to Docker Hardened Images with practical examples and best practices.
+      icon: code-bracket
+      link: /dhi/migration/examples/dotnet/
+    - title: Java
+      description: Learn how to migrate Java applications to Docker Hardened Images with practical examples and best practices.
+      icon: code-bracket
+      link: /dhi/migration/examples/java/
 ---
 
 This section provides detailed migration examples for common programming languages and frameworks.

content/manuals/dhi/migration/examples/dotnet.md

@@ -0,0 +1,134 @@
+---
+title: .NET
+description: Migrate a .NET application to Docker Hardened Images
+weight: 40
+keywords: dotnet, .net, csharp, aspnet, migration, dhi
+---
+
+> **Acknowledgment**
+>
+> Docker would like to thank [Naga Santhosh Reddy Vootukuri](https://github.com/sunnynagavo) for his contribution to this guide.
+
+This example shows how to migrate a .NET application to Docker Hardened Images.
+
+The following examples show Dockerfiles before and after migration to Docker
+Hardened Images. Each example includes four variations:
+
+- Before (Wolfi): A sample Dockerfile using Wolfi distribution images, before migrating to DHI
+- Before (DOI): A sample Dockerfile using Docker Official Images, before migrating to DHI
+- After (multi-stage): A sample Dockerfile after migrating to DHI with multi-stage builds (recommended for minimal, secure images)
+- After (single-stage): A sample Dockerfile after migrating to DHI with single-stage builds (simpler but results in a larger image with a broader attack surface)
+
+> [!NOTE]
+>
+> Multi-stage builds are recommended for most use cases. Single-stage builds are
+> supported for simplicity, but come with tradeoffs in size and security.
+>
+> You must authenticate to `dhi.io` before you can pull Docker Hardened Images.
+> Use your Docker ID credentials (the same username and password you use for
+> Docker Hub). If you don't have a Docker account, [create
+> one](../../../accounts/create-account.md) for free.
+>
+> Run `docker login dhi.io` to authenticate.
+
+{{< tabs >}}
+{{< tab name="Before (Wolfi)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+FROM cgr.dev/chainguard/dotnet-sdk:latest-dev AS builder
+
+WORKDIR /src
+COPY . ./
+
+# Install any additional packages if needed using apk
+# RUN apk add --no-cache git
+
+RUN dotnet restore
+RUN dotnet publish -c Release -o /src/out --no-restore
+
+FROM cgr.dev/chainguard/aspnet-runtime:latest
+
+WORKDIR /app
+COPY --from=builder /src/out ./
+
+ENTRYPOINT ["dotnet", "app.dll"]
+```
+
+{{< /tab >}}
+{{< tab name="Before (DOI)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+FROM mcr.microsoft.com/dotnet/sdk:8.0 AS builder
+
+WORKDIR /src
+COPY . ./
+
+# Install any additional packages if needed using apt
+# RUN apt-get update && apt-get install -y git && rm -rf /var/lib/apt/lists/*
+
+RUN dotnet restore
+RUN dotnet publish -c Release -o /app --no-restore
+
+FROM mcr.microsoft.com/dotnet/aspnet:8.0
+
+WORKDIR /app
+COPY --from=builder /app ./
+
+ENTRYPOINT ["dotnet", "app.dll"]
+```
+
+{{< /tab >}}
+{{< tab name="After (multi-stage)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+# === Build stage: Restore, build, and publish the .NET application ===
+FROM dhi.io/dotnet:8-sdk-alpine3.22 AS builder
+
+WORKDIR /src
+COPY . ./
+
+# Install any additional packages if needed using apk
+# RUN apk add --no-cache git
+
+RUN dotnet restore
+RUN dotnet publish -c Release -o /app --no-restore
+
+# === Final stage: Create minimal runtime image ===
+FROM dhi.io/aspnetcore:8-alpine3.22
+
+WORKDIR /app
+COPY --from=builder /app ./
+
+ENTRYPOINT ["dotnet", "app.dll"]
+```
+
+{{< /tab >}}
+{{< tab name="After (single-stage)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+FROM dhi.io/dotnet:8-sdk-alpine3.22
+
+WORKDIR /src
+COPY . ./
+
+# Install any additional packages if needed using apk
+# RUN apk add --no-cache git
+
+RUN dotnet restore
+RUN dotnet publish -c Release -o /app --no-restore
+
+WORKDIR /app
+
+ENTRYPOINT ["dotnet", "/app/app.dll"]
+```
+
+{{< /tab >}}
+{{< /tabs >}}

content/manuals/dhi/migration/examples/java.md

@@ -0,0 +1,154 @@
+---
+title: Java
+description: Migrate a Java application to Docker Hardened Images
+weight: 50
+keywords: java, jvm, jdk, jre, maven, migration, dhi
+---
+
+> **Acknowledgment**
+>
+> Docker would like to thank [Naga Santhosh Reddy Vootukuri](https://github.com/sunnynagavo) for his contribution to this guide.
+
+This example shows how to migrate a Java application to Docker Hardened Images.
+
+The following examples show Dockerfiles before and after migration to Docker
+Hardened Images. Each example includes five variations:
+
+- Before (Ubuntu): A sample Dockerfile using Ubuntu-based images, before migrating to DHI
+- Before (Wolfi): A sample Dockerfile using Wolfi distribution images, before migrating to DHI
+- Before (DOI): A sample Dockerfile using Docker Official Images, before migrating to DHI
+- After (multi-stage): A sample Dockerfile after migrating to DHI with multi-stage builds (recommended for minimal, secure images)
+- After (single-stage): A sample Dockerfile after migrating to DHI with single-stage builds (simpler but results in a larger image with a broader attack surface)
+
+> [!NOTE]
+>
+> Multi-stage builds are recommended for most use cases. Single-stage builds are
+> supported for simplicity, but come with tradeoffs in size and security.
+>
+> You must authenticate to `dhi.io` before you can pull Docker Hardened Images.
+> Use your Docker ID credentials (the same username and password you use for
+> Docker Hub). If you don't have a Docker account, [create
+> one](../../../accounts/create-account.md) for free.
+>
+> Run `docker login dhi.io` to authenticate.
+
+{{< tabs >}}
+{{< tab name="Before (Ubuntu)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+FROM ubuntu:24.04 AS builder
+
+WORKDIR /app
+COPY . ./
+
+RUN apt-get update && apt-get install -y default-jdk maven --no-install-recommends && rm -rf /var/lib/apt/lists/*
+
+RUN mvn -B package -DskipTests
+
+FROM ubuntu:24.04
+
+RUN apt-get update && apt-get install -y default-jre --no-install-recommends && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+COPY --from=builder /app/target/app.jar /app/app.jar
+
+ENTRYPOINT ["java", "-jar", "/app/app.jar"]
+```
+
+{{< /tab >}}
+{{< tab name="Before (Wolfi)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+FROM cgr.dev/chainguard/maven:latest-dev AS builder
+
+WORKDIR /app
+COPY . ./
+
+# Install any additional packages if needed using apk
+# RUN apk add --no-cache git
+
+RUN mvn -B package -DskipTests
+
+FROM cgr.dev/chainguard/jre:latest
+
+WORKDIR /app
+COPY --from=builder /app/target/app.jar /app/app.jar
+
+ENTRYPOINT ["java", "-jar", "/app/app.jar"]
+```
+
+{{< /tab >}}
+{{< tab name="Before (DOI)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+FROM maven:3.9-eclipse-temurin-21 AS builder
+
+WORKDIR /app
+COPY . ./
+
+# Install any additional packages if needed using apt
+# RUN apt-get update && apt-get install -y git && rm -rf /var/lib/apt/lists/*
+
+RUN mvn -B package -DskipTests
+
+FROM eclipse-temurin:21-jre
+
+WORKDIR /app
+COPY --from=builder /app/target/app.jar /app/app.jar
+
+ENTRYPOINT ["java", "-jar", "/app/app.jar"]
+```
+
+{{< /tab >}}
+{{< tab name="After (multi-stage)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+# === Build stage: Compile and package the Java application with Maven ===
+FROM dhi.io/maven:3-jdk21-alpine3.22-dev AS builder
+
+WORKDIR /app
+COPY . ./
+
+# Install any additional packages if needed using apk
+# RUN apk add --no-cache git
+
+RUN mvn -B package -DskipTests
+
+# === Final stage: Create minimal runtime image ===
+FROM dhi.io/eclipse-temurin:21-alpine3.22
+
+WORKDIR /app
+COPY --from=builder /app/target/app.jar /app/app.jar
+
+ENTRYPOINT ["java", "-jar", "/app/app.jar"]
+```
+
+{{< /tab >}}
+{{< tab name="After (single-stage)" >}}
+
+```dockerfile
+#syntax=docker/dockerfile:1
+
+FROM dhi.io/maven:3-jdk21-alpine3.22-dev
+
+WORKDIR /app
+COPY . ./
+
+# Install any additional packages if needed using apk
+# RUN apk add --no-cache git
+
+RUN mvn -B package -DskipTests
+
+ENTRYPOINT ["java", "-jar", "/app/target/app.jar"]
+```
+
+{{< /tab >}}
+{{< /tabs >}}