Migrating to Firebase Hosting without downtime?

[Henrik Hedlund]

Hi,

We are looking to migrate a live domain to Firebase hosting (previously pointing at Google App Engine). The problem we are facing in our tests is that Firebase does not seem to start generating the SSL certificate for the new custom domain until after the DNS A records have been configured.

That means that we have no way to avoid downtime. From our tests this downtime, which results in a pretty scary SSL error for the user, can be between 7 and 70 minutes. The documentation also states that it can take up to 24 hours for the SSL certificates to generate.

Does anyone know of any way of doing this without any downtime? Like getting Firebase to pre-generate the SSL certificates before we reconfigure the DNS (the domain is already verified after all).

Best regards,

Henrik