We are upgrading the version of the operating system that we use to run customer containers as part of the Docker executor on CircleCI.
This change should be mostly invisible to you, but you might notice this change if you are, for example, relying on a specific kernel version in your jobs.
We are slowly rolling out this change for all Docker executor customers, and we expect the rollout to be complete by April 1st, 2019.
Here are the facts:
A small portion of the Docker executor jobs are now executing on the machines with the upgraded OS. We will increase that portion slowly over the coming weeks.
Most of the underlying OS changes will not be visible to the Docker executor jobs, as those are isolated in their own containers. However, the upgrade includes a new kernel version which will be visible.
Some kernel-specific or OS-specific changes to data structures exported in virtual filesystems (such as
/proc/self/cgroup) will be visible in the Docker executor jobs.
The new version of the kernel is GNU/Linux 4.15.
The Docker version in the Docker executor is being upgraded from
Please comment on this post if you have any questions about this change. Thank you!