Fix SELinux labels to allow shared use.

Ensure that the volumes are not mounted as private, unshared volumes since we might mount with the host filesystem. This also fixes permissions issues with reading data from a mounted volume using a rootless container engine.

.changes/962.json

@@ -0,0 +1,5 @@
+{
+    "description": "fix SELinux labels to allow use in multiple containers and/or the host filesystem.",
+    "type": "fixed",
+    "issues": [961]
+}

src/docker/local.rs

@@ -14,7 +14,7 @@ fn mount(docker: &mut Command, host_path: &Path, absolute_path: &Path, prefix: &
     let mount_path = absolute_path.as_posix_absolute()?;
     docker.args(&[
         "-v",
-        &format!("{}:{prefix}{}", host_path.to_utf8()?, mount_path),
+        &format!("{}:{prefix}{}:z", host_path.to_utf8()?, mount_path),
     ]);
     Ok(())
 }
@@ -64,28 +64,28 @@ pub(crate) fn run(
     docker
         .args(&[
             "-v",
-            &format!("{}:{}:Z", dirs.xargo.to_utf8()?, dirs.xargo_mount_path()),
+            &format!("{}:{}:z", dirs.xargo.to_utf8()?, dirs.xargo_mount_path()),
         ])
         .args(&[
             "-v",
-            &format!("{}:{}:Z", dirs.cargo.to_utf8()?, dirs.cargo_mount_path()),
+            &format!("{}:{}:z", dirs.cargo.to_utf8()?, dirs.cargo_mount_path()),
         ])
         // Prevent `bin` from being mounted inside the Docker container.
         .args(&["-v", &format!("{}/bin", dirs.cargo_mount_path())]);
     docker.args(&[
         "-v",
-        &format!("{}:{}:Z", dirs.host_root.to_utf8()?, dirs.mount_root),
+        &format!("{}:{}:z", dirs.host_root.to_utf8()?, dirs.mount_root),
     ]);
     docker
         .args(&[
             "-v",
             &format!(
-                "{}:{}:Z,ro",
+                "{}:{}:z,ro",
                 dirs.get_sysroot().to_utf8()?,
                 dirs.sysroot_mount_path()
             ),
         ])
-        .args(&["-v", &format!("{}:/target:Z", dirs.target.to_utf8()?)]);
+        .args(&["-v", &format!("{}:/target:z", dirs.target.to_utf8()?)]);
     docker_cwd(&mut docker, &paths)?;
 
     // When running inside NixOS or using Nix packaging we need to add the Nix
@@ -94,7 +94,7 @@ pub(crate) fn run(
         docker.args(&[
             "-v",
             &format!(
-                "{}:{}:Z",
+                "{}:{}:z",
                 nix_store.to_utf8()?,
                 nix_store.as_posix_absolute()?
             ),