feat: Introduce "Hello, world" application example in C++

Signed-off-by: Alexander Jung <[email protected]>

README.md

@@ -24,6 +24,7 @@ kraft pkg ls --apps --update
 | | Example |
 |-|:-|
 | ![](https://raw.githubusercontent.com/unikraft/catalog/main/icons/c.svg) | [Simple "Hello, world!" application written in C](https://github.com/unikraft/catalog/tree/main/examples/helloworld-c) |
+| ![](https://raw.githubusercontent.com/unikraft/catalog/main/icons/cpp.svg) | [Simple "Hello, world!" application written in C++](https://github.com/unikraft/catalog/tree/main/examples/helloworld-cpp) |
 | ![](https://raw.githubusercontent.com/unikraft/catalog/main/icons/python3.svg) | [Simple Flask 3.0 HTTP Web Server](https://github.com/unikraft/catalog/tree/main/examples/http-python3.10-flask3.0) |
 | ![](https://raw.githubusercontent.com/unikraft/catalog/main/icons/python3.svg) | [Simple Python 3.10 HTTP Web Server with `http.server.HTTPServer`](https://github.com/unikraft/catalog/tree/main/examples/http-python3.10) |
 

examples/helloworld-cpp/Kraftfile

@@ -0,0 +1,26 @@
+spec: v0.6
+
+name: helloworld
+
+unikraft:
+  version: stable
+  kconfig:
+    CONFIG_LIBPOSIX_SYSINFO: y
+    CONFIG_LIBUKSIGNAL: y
+
+targets:
+- linuxu/x86_64
+- qemu/x86_64
+- xen/x86_64
+- qemu/arm64
+- fc/x86_64
+
+libraries:
+  libcxxabi: stable
+  libcxx: stable
+  libunwind: stable
+  compiler-rt:
+    version: stable
+    kconfig:
+      CONFIG_LIBCOMPILER_RT: 'y'
+  musl: stable

examples/helloworld-cpp/Makefile.uk

@@ -0,0 +1,3 @@
+$(eval $(call addlib,apphelloworldcpp))
+
+APPHELLOWORLDCPP_SRCS-y += $(APPHELLOWORLDCPP_BASE)/main.cpp

examples/helloworld-cpp/README.md

@@ -0,0 +1,27 @@
+# Simple "Hello, world!" C++ Program on Unikraft
+
+This directory contains an example "Hello, world!" application written in C++.
+
+To run this example, [install Unikraft's companion command-line toolchain `kraft`](https://unikraft.org/docs/cli).
+
+Then, clone this repository and cd into this directory.
+You can then build the project with:
+
+```
+kraft build
+```
+
+In the above command, `kraft build` will prompt you with the target you wish to compile for.
+If you are unsure, select `qemu/` and your host's architecture, e.g. `qemu/x86_64`.
+
+Once built, you can execute the unikernel via:
+
+```
+kraft run
+```
+
+## Learn more
+
+- [How to build unikernels](https://unikraft.org/docs/cli/building)
+- [How to run unikernels locally](https://unikraft.org/docs/cli/running)
+- [The `Kraftfile` specification](https://unikraft.org/docs/cli/reference/kraftfile/latest)

examples/helloworld-cpp/main.cpp

@@ -0,0 +1,6 @@
+#include <iostream>
+
+int main() {
+	std::cout << "Hello World!" << std::endl;
+	return 0;
+}