If an org is heavily invested in GitHub Actions and GitHub App integrations, is self-hosting GitHub enterprise the only practical option?

You could ask a quote from consultants on how much it would cost to migrate them... For large corporations it will probably be millions of euros.

Hopefully a good spot to plug my own project, preloop, which is a drop-in replacement of Github actions(both the runners and control plane) that runs locally or self-hosted in isoalted microvms, and supports debug-on-failure. You can also push to the server, run CI and then optionally create a draft PR. Not quite production-ready yet(for the self-hosted part), but the local part works well. We implement the official runner protocol 100% unlike act/gitea/forgejo, so your workflows are more likely to work out of the box with preloop(forgejo has the closest compatibility with Github Actions though so it's a good off-Github option) and we use microvms so no DinD issues. I'm working on getting the official runner vm image up to reduce any environment incompatibilities. Feel free to try it out: https://github.com/preloopdev/preloop

no; gitea and foregjo both support actions-style CI/CD and both serve mostly GH-compatible APIs and have GH-style apps. it's not 100% compatible (forgejo is a little more compatible than gitea [^1]), but many of your workflows might "just work" without even renaming the .github folder.

^1: in my recent experience, for my particular use cases

I'm one of the project leads of Gitea and we've put a ton of work into Gitea Actions, I'd be interested in any compatibility gaps that you've run into.

oh hello, thank you for your work on an excellent product! one small difference i ran into last weekend is that foregjo forwards the FORGEJO_TOKEN in the environment to composite actions so that they don't need to have a required "token" input.

mind trying https://github.com/preloopdev/preloop? We follow the official runner protocol 100% so we should hopefully have more workflow-compat.we also run in cross-platform microvms, not docker containers.

Buildkite has built a GitHub Actions adapter... a good first step out of the GitHub Actions supply chain attack trap.