2 files changed, 16 insertions, 3 deletions
diff --git a/src/runner/runc.rs b/src/runner/runc.rs
index ded73fa..0964ee9 100644
--- a/src/runner/runc.rs
+++ b/src/runner/runc.rs
@@ -7,11 +7,14 @@ use std::{io, process};
 use ipc_channel::ipc;
 use nix::{sys::signal, unistd};
 use serde::{Deserialize, Serialize};
+use sha2::Sha256;
 
 use crate::types::*;
 use crate::unshare;
 use crate::util::ipc::CheckDisconnect;
 
+pub type OutputHash = Sha256;
+
 #[derive(Debug, Deserialize, Serialize)]
 struct Request(TaskRef, Task, ipc::IpcSender<run::Error>);
 
diff --git a/src/runner/runc/run.rs b/src/runner/runc/run.rs
index 3fe51e1..14149d2 100644
--- a/src/runner/runc/run.rs
+++ b/src/runner/runc/run.rs
@@ -11,6 +11,8 @@ use nix::{
 	unistd,
 };
 use serde::{Deserialize, Serialize};
+use sha2::{digest, Digest};
+use tee_readwrite::TeeWriter;
 
 use crate::{
 	types::*,
@@ -18,7 +20,7 @@ use crate::{
 	util::{self, ToIOResult},
 };
 
-use super::spec;
+use super::{spec, OutputHash};
 
 #[derive(Debug, Deserialize, Serialize)]
 pub enum Error {
@@ -67,13 +69,21 @@ fn output_filename(task: TaskRef) -> PathBuf {
 	Path::new("build/state").join(format!("{}.tar", task))
 }
 
-fn collect_output(task: TaskRef, task_def: Task) -> Result<(), io::Error> {
+fn collect_output(task: TaskRef, task_def: Task) -> Result<digest::Output<OutputHash>, io::Error> {
 	let file = util::unix::create_as(
 		output_filename(task),
 		Some(unshare::BUILD_UID),
 		Some(unshare::BUILD_GID),
 	)?;
-	util::tar::pack(file, "build/tmp/runc/workdir", task_def.output.iter())?.sync_all()
+	let hasher = OutputHash::default();
+	let writer = TeeWriter::new(file, hasher);
+
+	let writer = util::tar::pack(writer, "build/tmp/runc/workdir", task_def.output.iter())?;
+	let (file, hasher) = writer.into_inner();
+
+	file.sync_all()?;
+
+	Ok(hasher.finalize())
 }
 
 pub fn handle_task(task: TaskRef, task_def: Task) -> Result<(), Error> {