Using Ignition after first boot?

[Eric Anderson]

From what I am reading in the docs, it appears that ignition is only executed on first boot. For further node configuration after first boot, are we to use Cloud-config or am I not understanding how to use ignition after that first boot? If so, how do you use ignition after the first boot?

[david....@coreos.com]

Hi,

Ignition is usually used to write your desired configuration to disk, so there is no need to run it on later boots.  If you need to perform some operation with Ignition again, you can add coreos.first_boot=1 to the kernel boot command-line to make it run again.

Thanks.

David

[Alex Crawford]

Ignition is not designed to be used for configuration management. For
that, you should use traditional CM tools (e.g. Ansible, Chef, Puppet).

-Alex

[Brandon Philips]

Or, commonly, what is happening with Kubernetes clusters, use DaemonSets for things that were usually deployed with Configuration management: logging daemons, network daemons, monitoring daemons, etc.

Thank You,

Brandon 

[Eric Anderson]

Thanks for the explanation and clarification. This makes a lot of sense. I would like to think of the CoreOS nodes as immutable but we have come across instances where we needed to update SSH keys for the core user or add/remove staff accounts. Beyond those tasks, I can not imagine scenarios where we are needing to perform config management after a node has been put into production. 

[Alex Crawford]

On 10/25, Eric Anderson wrote:
> I would like to think of the CoreOS nodes as immutable but we have come
> across instances where we needed to update SSH keys for the core user or
> add/remove staff accounts.

Bear in mind that coreos-cloudinit will only create accounts, so it
cannot be used for this scenario. One of the many reasons I'm looking
forward to its retirement.

-Alex