ZRAM not found in modules.dep

How to enable ZRAM?

$ modprobe zram
modprobe: module zram not found in modules.dep"

Am I doing something wrong?

most of the optional modules are in the kernel-extras service - which you need to enable & start:

[root@rancher-dev rancher]# ros service enable kernel-extras
Pulling kernel-extras (rancher/os-extras:4.9.10-rancher)...
4.9.10-rancher: Pulling from rancher/os-extras
b7f33cc0b48e: Pull complete
6ed9e06ced7b: Pull complete
f4d1700b2dc9: Pull complete
88a3aa0acbbc: Pull complete
Digest: sha256:4182efdcf0b9f6ff444b9105d320537237b9d7f828284e2b8ba6efb93b398fd9
Status: Downloaded newer image for rancher/os-extras:4.9.10-rancher
[root@rancher-dev rancher]# ros service up kernel-extras
> INFO[0000] Project [os]: Starting project
> INFO[0000] [0/17] [kernel-extras]: Starting
> INFO[0004] [1/17] [kernel-extras]: Started
> INFO[0004] Project [os]: Project started
[root@rancher-dev rancher]# modprobe zram
[root@rancher-dev rancher]# lsmod
Module                  Size  Used by    Not tainted
zram                   28672  0
xfrm_user              28672  1
xfrm_algo              16384  1 xfrm_user