But if you try to pin to a version that is too old, it may not work with updated versions of the Discourse base image. I can’t remember specific examples, but stuff like and old version of Discourse won’t work with Ruby 3.2, so you (sometimes) also need to pin discourse_docker if you pin to an old version of Discourse.
The safest and, in most cases, least wasteful solution is to build an image and push it to a repo rather than building a new image at every deployment. And if you have plugins, you’re likely to need to pin each of those as well.
I’ve done this for several clients for ECS as well as k8s on GCP and AWS.
I’m pretty sure that you can if you also pin discourse_docker to the old version. As I mentioned above, it’s more complicated with plugins, as you’re likely to need to pin those to the old versions as well. If you really want to maintain old versions building them exactly once and pushing them to a repo is the way to go. I’m doing this with a client to test upgrade paths from current production to latest and it’s working smoothly.