K3s Cluster Node(s) Upgrade about terraform-module-k3s HOT 8 CLOSED

Hi @nicklausbrown,

I've just checked (and tested) and here the upgrade process using followed by this module :

1. Downloads the latest installation script from Github
2. Reruns the installation script with the new k3s release
3. Waits until the node is ready

I therefore confirm that this module follows the official upgrade procedure by using the official installation script.

However, a word about the upgrade procedure wouldn't go amiss, thanks for bringing it up.

EDIT: replace using by followed by in order to avoid any misunderstanding

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@xunleii During the upgrade process, I noticed that all the nodes get upgraded simultaneously. This leads to a situation where all the master nodes are unavailable for a certain duration. Is there an option to perform the upgrades one after another instead?

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@xunleii What are your thoughts on introducing a feature flag for sequential execution that would, when enabled, enforce a sequential creation of servers and agents by adding a depends_on attribute to the preceding resource when the index is greater than 0? When this flag is disabled, which would be the default setting, the current behavior would be maintained.

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Yep, thank you for that. Indeed, there is no mechanism to have a non-parallel update. I did it because there is little downtime (in most cases) and I didn't want to make this module too complicated.

However, if it's something really blocking, I can make the first server serve as a dependency for the others. With this, there will always be at least one server available to communicate with, but I'll also have to find out if there's a risk of split brain N-1 servers updating at the same time.

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Not exactly a blocker but it breaks the HA guarantees in case of an HA setup. An option to have an one node at a time upgrade would be great.

from terraform-module-k3s.

@xunleii What are your thoughts on introducing a feature flag for sequential execution that would, when enabled, enforce a sequential creation of servers and agents by adding a depends_on attribute to the preceding resource when the index is greater than 0? When this flag is disabled, which would be the default setting, the current behavior would be maintained.

I agree with you, it can be very useful.
Unfortunately, I don't see how to implement it on Terraform; because it's a module and not a provider, I'm very limited on what I can do. For example here, node resources are created by a loop and all are made in parallel. I don't see how I can make it sequential instead 😞

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This issue has been automatically marked as stale because it has not had recent activity. If the issue still persists, please leave a comment and it will be reopened.

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This issue has been automatically marked as stale because it has not had recent activity. If the issue still persists, please leave a comment and it will be reopened.

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