Add Ruby-Hello application with Firecracker support

ruby-hello/Config.uk

@@ -0,0 +1,7 @@
+config APPRUBYHELLO
+    bool "ruby-hello"
+    default y
+    select LIBRUBY
+    select LIBNEWLIBC
+    select LIBLWIP
+    select LIBPTHREAD_EMBEDDED

ruby-hello/Makefile

@@ -0,0 +1,9 @@
+UK_ROOT ?= $(PWD)/workdir/unikraft
+UK_LIBS ?= $(PWD)/workdir/libs
+LIBS := $(UK_LIBS)/newlib:$(UK_LIBS)/lwip:$(UK_LIBS)/pthread-embedded:$(UK_LIBS)/ruby:$(UK_LIBS)/compiler-rt
+
+all:
+	@make -C $(UK_ROOT) A=$(PWD) L=$(LIBS)
+
+$(MAKECMDGOALS):
+	@make -C $(UK_ROOT) A=$(PWD) L=$(LIBS) $(MAKECMDGOALS)

ruby-hello/Makefile.uk

@@ -0,0 +1,4 @@
+$(eval $(call addlib,apprubyhello))
+
+# Adding the rootfs directory as the filesystem entry point
+APP_ROOTFS_FLAGS-y += -DROOTFS_DIR=\"$(APP_BASE)/rootfs\"

ruby-hello/README.md

@@ -0,0 +1,51 @@
+# Ruby Hello on Unikraft
+
+Build and run a Ruby Hello program as a Unikraft unikernel. Follow the instructions below to set up, configure, build, and run the application using the standard Makefile-based workflow.
+
+## Set Up
+
+Set up the required repositories by creating symbolic links to the central resource directory. Be sure to run the top-level setup.sh script first to populate the global repos/ directory.
+
+## Shell
+
+```console
+./setup.sh
+```
+
+## Clean
+
+While not strictly required, it is safest to clean the previous build artifacts before a new configuration:
+
+```console
+make distclean
+```
+
+## Configure
+
+To configure the unikernel, use the standard menu interface:
+
+```console
+make menuconfig
+```
+
+In the menu, select the target architecture (e.g., x86_64) and the platform (e.g., KVM guest). Under Library Configuration, ensure ruby is selected and configure any necessary extensions.
+
+## Build
+
+Build the application for the current configuration:
+
+```console
+make -j $(nproc)
+```
+
+The resulting unikernel image will be created in the build/ directory as ruby-hello_kvm-x86_64.
+
+## Run
+To run the resulting image on Firecracker (x86_64), use the following command:
+
+```console
+rm -f firecracker.socket
+firecracker-x86_64 --config-file fc.x86_64.json --api-sock firecracker.socket
+```
+
+A successful run will start the Ruby interpreter and execute the helloworld.rb script inside the unikernel.

ruby-hello/fc.x86_64.json

@@ -0,0 +1,12 @@
+{
+  "boot-source": {
+    "kernel_image_path": "build/ruby-hello_kvm-x86_64",
+    "boot_args": "ruby-hello_kvm-x86_64 -- /helloworld.rb"
+  },
+  "drives": [],
+  "machine-config": {
+    "vcpu_count": 1,
+    "mem_size_mib": 256,
+    "ht_enabled": false
+  }
+}

ruby-hello/helloworld.rb

@@ -0,0 +1 @@
+puts 'Hello, world!'

ruby-hello/setup.sh

@@ -0,0 +1,37 @@
+#!/bin/sh
+
+check_exists_and_create_symlink()
+{
+    path="$1"
+
+    if ! test -d workdir/"$path"; then
+        if ! test -d ../repos/"$path"; then
+            echo "No directory ../repos/$path. Run the top-level setup.sh script first." 1>&2
+            exit 1
+        fi
+        depth=$(echo "$path" | awk -F / '{ print NF }')
+        if test "$depth" -eq 1; then
+            ln -sfn ../../repos/"$path" workdir/"$path"
+        elif test "$depth" -eq 2; then
+            ln -sfn ../../../repos/"$path" workdir/"$path"
+        else
+            echo "Unknown depth of path $path." 1>&2
+            exit 1
+        fi
+    fi
+}
+
+if ! test -d workdir; then
+    mkdir workdir
+fi
+
+if ! test -d workdir/libs; then
+    mkdir workdir/libs
+fi
+
+check_exists_and_create_symlink "unikraft"
+check_exists_and_create_symlink "libs/newlib"
+check_exists_and_create_symlink "libs/lwip"
+check_exists_and_create_symlink "libs/compiler-rt"
+check_exists_and_create_symlink "libs/pthread-embedded"
+check_exists_and_create_symlink "libs/ruby"

setup.sh

@@ -15,3 +15,8 @@ test -d repos/apps/elfloader || git clone https://github.com/unikraft/app-elfloa
 test -d repos/libs/redis || git clone https://github.com/unikraft/lib-redis repos/libs/redis
 test -d repos/libs/wamr || git clone https://github.com/unikraft/lib-wamr repos/libs/wamr
 test -d repos/libs/sqlite || git clone https://github.com/unikraft/lib-sqlite repos/libs/sqlite
+
+# for ruby
+test -d repos/libs/newlib || git clone https://github.com/unikraft/lib-newlib repos/libs/newlib
+test -d repos/libs/pthread-embedded || git clone https://github.com/unikraft/lib-pthread-embedded repos/libs/pthread-embedded
+test -d repos/libs/ruby || git clone https://github.com/unikraft/lib-ruby repos/libs/ruby