feat(tempfile): allow usage of custom tempdir locations

src/bin/uhyve.rs

@@ -56,6 +56,16 @@ struct Args {
 	#[clap(long)]
 	file_mapping: Vec<String>,
 
+	/// The path that should be used for temporary directories storing unmapped files.
+	///
+	/// This is useful for manually created tmpfs filesystems and for selecting
+	/// directories not managed by a temporary file cleaner, which can remove open files
+	/// manually. In most cases, mapping the guest path /root/ instead should be sufficient.
+	///
+	/// Defaults to /tmp.
+	#[clap(long)]
+	tempdir: Option<String>,
+
 	#[clap(flatten, next_help_heading = "Memory OPTIONS")]
 	memory_args: MemoryArgs,
 
@@ -257,6 +267,7 @@ impl From<Args> for Params {
 			#[cfg(target_os = "linux")]
 			gdb_port,
 			file_mapping,
+			tempdir,
 			kernel: _,
 			kernel_args,
 			output,
@@ -277,6 +288,7 @@ impl From<Args> for Params {
 			#[cfg(target_os = "macos")]
 			gdb_port: None,
 			kernel_args,
+			tempdir,
 			// TODO
 			output: if let Some(outp) = output {
 				Output::from_str(&outp).unwrap()

src/isolation/filemap.rs

@@ -24,15 +24,16 @@ impl UhyveFileMap {
 	/// Creates a UhyveFileMap.
 	///
 	/// * `mappings` - A list of host->guest path mappings with the format "./host_path.txt:guest.txt"
-	pub fn new(mappings: &[String]) -> UhyveFileMap {
+	/// * `tempdir` - Path to create temporary directory on
+	pub fn new(mappings: &[String], tempdir: &Option<String>) -> UhyveFileMap {
 		UhyveFileMap {
 			files: mappings
 				.iter()
 				.map(String::as_str)
 				.map(Self::split_guest_and_host_path)
 				.map(Result::unwrap)
 				.collect(),
-			tempdir: create_temp_dir(),
+			tempdir: create_temp_dir(tempdir),
 		}
 	}
 
@@ -193,7 +194,7 @@ mod tests {
 			path_prefix.clone() + "/this_symlink_leads_to_a_file" + ":guest_file_symlink",
 		];
 
-		let mut map = UhyveFileMap::new(&map_parameters);
+		let mut map = UhyveFileMap::new(&map_parameters, &None);
 
 		assert_eq!(
 			map.get_host_path("readme_file.md").unwrap(),
@@ -245,7 +246,7 @@ mod tests {
 			host_path_map.to_str().unwrap(),
 			guest_path_map.to_str().unwrap()
 		)];
-		let mut map = UhyveFileMap::new(&uhyvefilemap_params);
+		let mut map = UhyveFileMap::new(&uhyvefilemap_params, &None);
 
 		let mut found_host_path = map.get_host_path(target_guest_path.clone().to_str().unwrap());
 
@@ -276,7 +277,7 @@ mod tests {
 			guest_path_map.to_str().unwrap()
 		)];
 
-		map = UhyveFileMap::new(&uhyvefilemap_params);
+		map = UhyveFileMap::new(&uhyvefilemap_params, &None);
 
 		target_guest_path = PathBuf::from("/root/this_symlink_leads_to_a_file");
 		target_host_path = fixture_path.clone();
@@ -289,7 +290,7 @@ mod tests {
 
 		// Tests directory traversal with no maps
 		let empty_array: [String; 0] = [];
-		map = UhyveFileMap::new(&empty_array);
+		map = UhyveFileMap::new(&empty_array, &None);
 		found_host_path = map.get_host_path(target_guest_path.to_str().unwrap());
 		assert!(found_host_path.is_none());
 	}

src/isolation/tempdir.rs

@@ -1,15 +1,30 @@
 use std::{fs::Permissions, os::unix::fs::PermissionsExt};
 
 use tempfile::{Builder, TempDir};
+use uuid::Uuid;
 
 /// Creates a temporary directory.
-pub fn create_temp_dir() -> TempDir {
-	let dir = Builder::new()
-		.permissions(Permissions::from_mode(0o700))
-		.prefix("uhyve-")
-		.tempdir()
-		.ok()
-		.unwrap_or_else(|| panic!("The temporary directory could not be created."));
+///
+/// * `dir_path` - The location in which the temporary directory should be created.
+pub fn create_temp_dir(dir_path: &Option<String>) -> TempDir {
+	let dir: TempDir;
+	if let Some(dir_path) = dir_path {
+		dir = Builder::new()
+			.permissions(Permissions::from_mode(0o700))
+			.prefix("uhyve-")
+			.suffix(&Uuid::new_v4().to_string())
+			.tempdir_in(dir_path)
+			.ok()
+			.unwrap_or_else(|| panic!("The temporary directory could not be created."));
+	} else {
+		dir = Builder::new()
+			.permissions(Permissions::from_mode(0o700))
+			.prefix("uhyve-")
+			.suffix(&Uuid::new_v4().to_string())
+			.tempdir()
+			.ok()
+			.unwrap_or_else(|| panic!("The temporary directory could not be created."));
+	}
 
 	let dir_permissions = dir.path().metadata().unwrap().permissions();
 	assert!(!dir_permissions.readonly());

src/params.rs

@@ -38,6 +38,9 @@ pub struct Params {
 	/// Mapped paths between the guest and host OS
 	pub file_mapping: Vec<String>,
 
+	/// Path to create temporary directory on
+	pub tempdir: Option<String>,
+
 	/// Kernel output handling
 	pub output: Output,
 
@@ -59,6 +62,7 @@ impl Default for Params {
 			cpu_count: Default::default(),
 			gdb_port: Default::default(),
 			file_mapping: Default::default(),
+			tempdir: Default::default(),
 			kernel_args: Default::default(),
 			output: Default::default(),
 			stats: false,

src/vm.rs

@@ -185,7 +185,7 @@ impl<VirtBackend: VirtualizationBackend> UhyveVm<VirtBackend> {
 			"gdbstub is only supported with one CPU"
 		);
 
-		let file_mapping = Mutex::new(UhyveFileMap::new(&params.file_mapping));
+		let file_mapping = Mutex::new(UhyveFileMap::new(&params.file_mapping, &params.tempdir));
 
 		let output = match params.output {
 			params::Output::None => Output::None,