I ran into a small problem changing the boot parameters get AppArmor working on Debian with Linode. I am writing this in case anyone runs into same issue.
The command-line instructions given by the debian wiki shows the following kernel parameters need to be set using grub:
GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT apparmor=1 security=apparmor"
Following a reboot, a read of /proc/cmdline revealed that the kernel parameters were not used. This is because Linode defaults to using their own kernel, you will need to explicitly set GRUB 2 to boot in the Linode Manager.
Login to the Linode Manager, click the node relevant node and locate the 'Configuration Profile'. Change the kernel to 'GRUB 2'.
Reboot and see what happens. Good luck!