Add missing capabilities

pkg/selfcontain/defaults.go

@@ -192,6 +192,7 @@ var capabilities = []string{
 	"CAP_AUDIT_WRITE",
 	"CAP_SETFCAP",
 	"CAP_FSETID",
+  "CAP_SYS_PTRACE", // To read ns/ipc files
 }
 
 // These networks will be setup as a default base inside the container