feat: create init file

Signed-off-by: BioTheWolff <[email protected]>

src/fs-gen/src/initramfs_generator.rs

@@ -0,0 +1,25 @@
+use std::fs::{File, Permissions};
+use std::os::unix::fs::PermissionsExt;
+use std::io::Write;
+use std::path::Path;
+
+const INIT_FILE: &[u8;220] = b"#! /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
+
+exec /sbin/getty -n -l /bin/sh 115200 /dev/console
+poweroff -f
+";
+
+pub fn create_init_file(path: &Path) {
+    let file_path = path.join("init");
+    let mut file = File::create(file_path).unwrap();
+
+    file.write_all(INIT_FILE).expect("Could not write init file");
+    file.set_permissions(Permissions::from_mode(0o755)).unwrap();
+}

src/fs-gen/src/main.rs

@@ -1,10 +1,12 @@
 use std::{fs, path::{Path, PathBuf}, str::FromStr};
 
 use image_builder::merge_layer;
+use crate::initramfs_generator::create_init_file;
 
 mod cli_args;
 mod image_builder;
 mod image_loader;
+mod initramfs_generator;
 
 fn main() {
     let args = cli_args::CliArgs::get_args();
@@ -26,6 +28,7 @@ fn main() {
                 println!(" - {}", path.display());
             }
             merge_layer(&layers_paths, Path::new("/tmp/cloudlet"));
+            create_init_file(Path::new("/tmp/cloudlet"));
         }
     }
 }