The issue with the original Supervisor implementation of the firewall is that
on Supervisor start, the Supervisor flushes the INPUT chain of the filter table.
This doesn't play well with services that add to the INPUT chain on startup that
may start up before the Supervisor, such as certain NetworkManager connection
profiles. This change only replaces the BALENA-FIREWALL rule in the INPUT chain,
preserving the other rules as well as their order.
Closes: #1482
Change-type: patch
Signed-off-by: Christina Ying Wang <christina@balena.io>
