hypha: implement basic container init

hypha/src/container/init.rs

@@ -0,0 +1,48 @@
+use crate::error::Result;
+use std::fs;
+use std::path::Path;
+use sys_mount::{FilesystemType, Mount, MountFlags};
+
+const IMAGE_BLOCK_DEVICE_PATH: &str = "/dev/xvda";
+const CONFIG_BLOCK_DEVICE_PATH: &str = "/dev/xvdb";
+
+const IMAGE_MOUNT_PATH: &str = "/image";
+const CONFIG_MOUNT_PATH: &str = "/config";
+
+pub struct ContainerInit {}
+
+impl Default for ContainerInit {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl ContainerInit {
+    pub fn new() -> ContainerInit {
+        ContainerInit {}
+    }
+
+    pub fn init(&mut self) -> Result<()> {
+        self.prepare_mounts()?;
+        Ok(())
+    }
+
+    fn prepare_mounts(&mut self) -> Result<()> {
+        let image_mount_path = Path::new(IMAGE_MOUNT_PATH);
+        let config_mount_path = Path::new(CONFIG_MOUNT_PATH);
+        self.mount_squashfs(Path::new(IMAGE_BLOCK_DEVICE_PATH), image_mount_path)?;
+        self.mount_squashfs(Path::new(CONFIG_BLOCK_DEVICE_PATH), config_mount_path)?;
+        Ok(())
+    }
+
+    fn mount_squashfs(&mut self, from: &Path, to: &Path) -> Result<()> {
+        if !to.is_dir() {
+            fs::create_dir(to)?;
+        }
+        Mount::builder()
+            .fstype(FilesystemType::Manual("squashfs"))
+            .flags(MountFlags::RDONLY)
+            .mount(from, to)?;
+        Ok(())
+    }
+}

hypha/src/container/mod.rs

@@ -1 +1 @@
-
+pub mod init;