1 files changed, 127 insertions, 0 deletions
diff --git a/crates/rebel-runner/src/util/fs.rs b/crates/rebel-runner/src/util/fs.rs
new file mode 100644
index 0000000..9e33eb7
--- /dev/null
+++ b/crates/rebel-runner/src/util/fs.rs
@@ -0,0 +1,127 @@
+use std::{
+	fs::{self, File},
+	io,
+	os::unix::prelude::*,
+	path::{Path, PathBuf},
+};
+
+use nix::{
+	fcntl::OFlag,
+	mount::{self, MsFlags},
+	unistd,
+};
+
+use rebel_common::error::*;
+
+pub fn open<P: AsRef<Path>>(path: P) -> Result<fs::File> {
+	fs::File::open(path.as_ref())
+		.with_context(|| format!("Failed to open file {:?} for reading", path.as_ref()))
+}
+
+pub fn create<P: AsRef<Path>>(path: P) -> Result<fs::File> {
+	fs::File::create(path.as_ref())
+		.with_context(|| format!("Failed to open file {:?} for writing", path.as_ref()))
+}
+
+pub fn rename<P1: AsRef<Path>, P2: AsRef<Path>>(from: P1, to: P2) -> Result<()> {
+	fs::rename(from.as_ref(), to.as_ref())
+		.with_context(|| format!("Failed to rename {:?} to {:?}", from.as_ref(), to.as_ref()))
+}
+
+// Unlike fs::copy, this doesn't preserve file flags
+pub fn copy<P1: AsRef<Path>, P2: AsRef<Path>>(from: P1, to: P2) -> Result<()> {
+	(|| -> Result<()> {
+		let mut src = open(from.as_ref())?;
+		let mut dest = create(to.as_ref())?;
+		io::copy(&mut src, &mut dest)?;
+		dest.sync_all()?;
+		Ok(())
+	})()
+	.with_context(|| format!("Failed to copy {:?} to {:?}", from.as_ref(), to.as_ref()))
+}
+
+pub fn mkdir<P: AsRef<Path>>(path: P) -> Result<()> {
+	let mut builder = fs::DirBuilder::new();
+	builder.recursive(true);
+	builder
+		.create(path.as_ref())
+		.with_context(|| format!("Failed to create directory {:?}", path.as_ref()))
+}
+
+pub fn ensure_removed<P: AsRef<Path>>(path: P) -> Result<()> {
+	let result = if path.as_ref().is_dir() {
+		fs::remove_dir_all(path.as_ref())
+	} else {
+		fs::remove_file(path.as_ref())
+	};
+	result
+		.or_else(|err| match err.kind() {
+			io::ErrorKind::NotFound => Ok(()),
+			_ => Err(err),
+		})
+		.with_context(|| format!("Failed to delete {:?}", path.as_ref()))
+}
+
+pub fn is_dir_empty<P: AsRef<Path>>(path: P) -> Result<bool> {
+	Ok(fs::read_dir(path)?.next().is_none())
+}
+
+/// Fixes up weirdness of set-group-ID or bsdgroups
+pub fn fixup_permissions<P: AsRef<Path>>(path: P) -> Result<()> {
+	let path = path.as_ref();
+	let gid = unistd::getegid();
+
+	let metadata = path
+		.metadata()
+		.with_context(|| format!("Failed to get metadata of {:?}", path))?;
+
+	if metadata.gid() != gid.as_raw() {
+		unistd::chown(path, None, Some(gid))
+			.with_context(|| format!("Failed to set group of {:?}", path))?;
+	}
+
+	let mut perms = metadata.permissions();
+	let mode = perms.mode();
+	if (mode & 0o777) != mode {
+		perms.set_mode(mode & 0o777);
+		std::fs::set_permissions(path, perms)
+			.with_context(|| format!("Failed to set mode of {:?}", path))?;
+	}
+
+	Ok(())
+}
+
+#[must_use]
+pub struct Mount(PathBuf);
+
+impl Drop for Mount {
+	fn drop(&mut self) {
+		mount::umount(&self.0)
+			.with_context(|| format!("Failed to unmount {:?}", self.0))
+			.unwrap();
+	}
+}
+
+pub fn mount<P1: AsRef<Path>, P2: AsRef<Path>>(
+	source: P1,
+	target: P2,
+	fstype: Option<&str>,
+	flags: MsFlags,
+	data: Option<&str>,
+) -> Result<Mount> {
+	mkdir(target.as_ref()).with_context(|| format!("Failed to create {:?}", target.as_ref()))?;
+
+	let canon_target = target
+		.as_ref()
+		.canonicalize()
+		.with_context(|| format!("Failed to get absolute path for {:?}", target.as_ref()))?;
+	mount::mount(Some(source.as_ref()), &canon_target, fstype, flags, data)
+		.with_context(|| format!("Failed to mount {:?}", canon_target))?;
+	Ok(Mount(canon_target))
+}
+
+pub fn pipe() -> Result<(File, File)> {
+	unistd::pipe2(OFlag::O_CLOEXEC)
+		.context("pipe2()")
+		.map(|(piper, pipew)| (File::from(piper), File::from(pipew)))
+}