apparmor: permit signals from unconfined programs
Otherwise if you try to kill a container process from the host directly,
you get EACCES. Also add a comment to make sure that the profile code
(which has been replicated by several projects) doesn't get out of sync.
package apparmor // import "github.com/docker/docker/profiles/apparmor"
+// NOTE: This profile is replicated in containerd and libpod. If you make a
+// change to this profile, please make follow-up PRs to those projects so
+// that these rules can be synchronised (because any issue with this
+// profile will likely affect libpod and containerd).
+// TODO: Move this to a common project so we can maintain it in one spot.
+
// baseTemplate defines the default apparmor profile for containers.
const baseTemplate = `
{{range $value := .Imports}}
@@ -18,9 +24,11 @@ profile {{.Name}} flags=(attach_disconnected,mediate_deleted) {
file,
umount,
{{if ge .Version 208096}}
-{{/* Allow 'docker kill' to actually send signals to container processes. */}}
+ # Host (privileged) processes may send signals to container processes.
+ signal (receive) peer=unconfined,
+ # dockerd may send signals to container processes (for "docker kill").
signal (receive) peer={{.DaemonProfile}},
-{{/* Allow container processes to send signals amongst themselves. */}}
+ # Container processes may send signals amongst themselves.
signal (send,receive) peer={{.Name}},
{{end}}
