Updating The Default Base AMI

With the release of kOps 1.18, the base AMI was switched over from a pre-baked kOps AMI to the official Ubuntu 20.04 LTS image. This makes the image update process easier, because kOps contributors no longer have to fully build and test a full AMI, but rather base off of the latest stable Ubuntu image. In order to make sure we’re up to date with the latest releases, we regularly follow the official Ubuntu EC2 AMI Locator website and update to the latest version of focal which is available across all AWS regions, including gov and cn, for full support.

The process of updating the AMI version is as following:

  • Find the most recent release on the official Ubuntu EC2 AMI Locator. Make sure it’s available across all regions. The ones with the slowest release cycle are usually gov, ap and cn ones, so the best option would usually be to take the most recent release from one of these regions.

  • Replace the timestamp on this line in the alpha channel, where the ubuntu image is referred. Example.

    Note

    Before updating alpha channel, check and see if alpha and stable channel are both running the same AMI version. If stable currently runs a different version, and more than 7-10 days passed since alpha was updated- it’s safe to also push the version currently in alpha, to stable in the same PR. e.g., let’s say that the most recent available on Ubuntu image locator is 20201210, alpha is currently using 20201101 and stable is currently using 20201015. If alpha was updated at least 7-10 days prior to your desired change, you can update stable with the version that was listed in alpha before your change. Then- you may update alpha with the most recent version of Ubuntu.

    Note

    When updating the stable channel with a new ami version, there’s a pretty good chance that this will cause some tests to fail. Thus, it’s worth running hack/update-expected.sh. This will update all the integration tests with the newly updated ami. To get ahead of this locally before pushing - make test will confirm that everything is updated as should.

  • Let the new AMI version bake-in in alpha channel for at least 7-10 days, afterwhich it’s safe to create a follow-up PR to push the latest version to stable channel.