The releases.yml on releases.rancher.com should be bump to v1.5.7

[levee223]

Since v1.5.7 is not defined in https://releases.rancher.com/os/releases.yml, we cannot upgrade to v1.5.7 using sudo ros os upgrade.

[olljanat]

Note that RancherOS is EOL #3000 and unsupported. Only reason why they still released v1.5.7 is because they still have some customer which have support contract for RancherOS.

I highly recommend for everyone else that you consider switch to BurmillaOS v1.9.1 which also uses Docker 19.03.15 and let you easily switch to 20.10.x versions too.

[abuisine]

You just have to produce a valid releases.yml file.
As an example, you could use a gist I just created (which points to 1.5.8)

ros config set rancher.upgrade.url https://gist.githubusercontent.com/abuisine/29e18fda1b13b1f2c9f57429d75ebef1/raw/bdb61803f10d13527e9d1471a8897443c97f63f3/releases.yml
ros os list
ros os upgrade

Burmilla is quite a cool fork as well https://github.com/burmilla/os