feat(vmm): implemented automatic generation of rootfs with initramfs

src/vmm/src/service.rs

@@ -5,6 +5,7 @@ use crate::core::vmm::VMM;
 use crate::VmmErrors;
 use std::{
     convert::From,
+    env::current_dir,
     net::Ipv4Addr,
     path::{Path, PathBuf},
     process::{Command, Stdio},
@@ -42,9 +43,16 @@ impl VmmServiceTrait for VmmService {
         const HOST_IP: Ipv4Addr = Ipv4Addr::new(172, 29, 0, 1);
         const HOST_NETMASK: Ipv4Addr = Ipv4Addr::new(255, 255, 0, 0);
 
+        // get current directory
+        let mut curr_dir = current_dir()?;
+
+        // define kernel path
+        let mut kernel_entire_path = curr_dir.as_os_str().to_owned();
+        kernel_entire_path.push("/tools/kernel/linux-cloud-hypervisor/arch/x86/boot/compressed/vmlinux.bin");
+
         // Check if the kernel is on the system, else build it
-        if !Path::new("./tools/kernel/linux-cloud-hypervisor/arch/x86/boot/compressed/vmlinux.bin")
-            .exists()
+        let kernel_exists = Path::new(&kernel_entire_path).try_exists().expect(&format!("Could not access folder {:?}", &kernel_entire_path));
+        if !kernel_exists
         {
             info!("Kernel not found, building kernel");
             // Execute the script using sh and capture output and error streams
@@ -56,19 +64,35 @@ impl VmmServiceTrait for VmmService {
                 .expect("Failed to execute the kernel build script");
 
             // Print output and error streams
-            error!("Script output: {}", String::from_utf8_lossy(&output.stdout));
+            info!("Script output: {}", String::from_utf8_lossy(&output.stdout));
             error!("Script errors: {}", String::from_utf8_lossy(&output.stderr));
         };
+        let kernel_path = Path::new(&kernel_entire_path);
+
+        // define initramfs file placement
+        let initramfs_entire_file_path = curr_dir.as_mut_os_string();
+        initramfs_entire_file_path.push("/tools/rootfs/initramfs.img");
+
+        // Check if the initramfs is on the system, else build it
+        let initramfs_exists = Path::new(&initramfs_entire_file_path).try_exists().expect(&format!("Could not access folder {:?}", &initramfs_entire_file_path));
+        if !initramfs_exists
+        {
+            info!("Initramfs not found, building initramfs");
+            // Execute the script using sh and capture output and error streams
+            let output = Command::new("sh")
+                .arg("./tools/rootfs/mkrootfs.sh")
+                .stdout(Stdio::piped())
+                .stderr(Stdio::piped())
+                .output()
+                .expect("Failed to execute the initramfs build script");
 
-        let kernel_path = &Path::new(
-            "./tools/kernel/linux-cloud-hypervisor/arch/x86/boot/compressed/vmlinux.bin",
-        );
-        let mut initramfs_path: PathBuf = PathBuf::new();
-
-        // Todo - Check if the initramfs for the specified language is on the system, else build it
-        initramfs_path.push("./tools/rootfs/initramfs.img");
+            // Print output and error streams
+            info!("Script output: {}", String::from_utf8_lossy(&output.stdout));
+            error!("Script errors: {}", String::from_utf8_lossy(&output.stderr));
+        };
+        let initramfs_path = PathBuf::from(&initramfs_entire_file_path);
 
-        // // Create a new VMM
+        // Create a new VMM
         let mut vmm = VMM::new(HOST_IP, HOST_NETMASK).map_err(VmmErrors::VmmNew)?;
 
         // Configure the VMM parameters might need to be calculated rather than hardcoded

tools/kernel/linux-config-x86_64

@@ -1475,6 +1475,8 @@ CONFIG_VIRTIO_NET=y
 # CONFIG_PPP is not set
 CONFIG_SLIP=y
 CONFIG_SLIP_COMPRESSED=y
+CONFIG_SLIP_SMART=n
+CONFIG_SLIP_MODE_SLIP6=n
 
 #
 # Host-side USB support is needed for USB Network Adapter support

tools/kernel/mkkernel.sh

@@ -1,13 +1,13 @@
 #!/usr/bin/bash
 
 LINUX_REPO=linux-cloud-hypervisor
+cd ./tools/kernel/
 
 if [ ! -d $LINUX_REPO ]
 then
     git clone --depth 1 "https://github.com/cloud-hypervisor/linux.git" -b "ch-6.2" $LINUX_REPO
 fi
 
-pushd $LINUX_REPO
+cd $LINUX_REPO
 cp ../linux-config-x86_64 .config
 KCFLAGS="-Wa,-mx86-used-note=no" make bzImage -j `nproc`
-popd

tools/rootfs/mkrootfs.sh

@@ -1,41 +1,14 @@
 #!/usr/bin/bash
-
-if [ ! -d alpine-minirootfs ]
+# test if its already in src folder => fs-gen available
+# launch from src folder at the same level as tools
+if [ -d src ]
 then
-    curl -O https://dl-cdn.alpinelinux.org/alpine/v3.14/releases/x86_64/alpine-minirootfs-3.14.2-x86_64.tar.gz
-
-    mkdir alpine-minirootfs
-    tar xf alpine-minirootfs-3.14.2-x86_64.tar.gz -C alpine-minirootfs
+    cd src
 fi
 
-pushd alpine-minirootfs
-cat > init <<EOF
-#! /bin/sh
-#
-# /init executable file in the initramfs
-#
-mount -t devtmpfs dev /dev
-mount -t proc proc /proc
-mount -t sysfs sysfs /sys
-
-ip link set up dev lo
-
-slattach -L /dev/ttyS1&
-
-while ! ifconfig sl0 &> /dev/null; do
-    sleep 1
-done
-
-ifconfig sl0 172.30.0.11 netmask 255.255.0.0 up
-
-exec /sbin/getty -n -l /bin/sh 115200 /dev/console
-poweroff -f
-EOF
-
-chmod +x init
-
-find . -print0 |
-    cpio --null --create --verbose --owner root:root --format=newc |
-    xz -9 --format=lzma  > ../initramfs.img
-
-popd
+if [ -d fs-gen ]
+then
+    cargo run --bin fs-gen -- alpine:latest ./fs-gen/test -o ../tools/rootfs/initramfs.img
+else
+    echo "Module fs-gen not found"
+fi