Switch Metropolis to EROFS-based root filesystem
This gets rid of the old large initramfs and switches to an EROFS-based root
filesystem. It also drops the copy & remount compatibility code. As this filesystem is
properly read-only and not just ephemeral, this also brings various changes to the code
to make systems compatible with that.
Test Plan: Covered by E2E tests, also manually smoke-tested.
X-Origin-Diff: phab/D696
GitOrigin-RevId: 037f2b8253e7cff8435cc79771fad05f53670ff0
diff --git a/metropolis/node/core/cluster/node.go b/metropolis/node/core/cluster/node.go
index 92ff072..7d26213 100644
--- a/metropolis/node/core/cluster/node.go
+++ b/metropolis/node/core/cluster/node.go
@@ -205,7 +205,7 @@
// ConfigureLocalHostname uses the node's ID as a hostname, and sets the current hostname, and local files like hosts
// and machine-id accordingly.
-func (n *Node) ConfigureLocalHostname(etc *localstorage.EtcDirectory) error {
+func (n *Node) ConfigureLocalHostname(etc *localstorage.EphemeralDirectory) error {
if err := unix.Sethostname([]byte(n.ID())); err != nil {
return fmt.Errorf("failed to set runtime hostname: %w", err)
}