Implement extended maintenance mode

[lkraav]

Feature Request

• Yes, I reviewed the contribution guidelines.

Describe your use case and the problem you are facing

I need to migrate a WP VLDB (Very Large Database) to another server.

Core maintenance mode auto-expiring in 10 minutes was a surprise discovery.

Some long maintenance jobs may require much more time.

Describe the solution you'd like

wp maintenance-mode activate could take maybe a --manual parameter to deploy an unexpiring $upgrading = time() file, as seems to the best practice for this use case shown at https://wordpress.stackexchange.com/questions/211303/wp-cli-enabling-maintainance-mode and elsewhere.

Y'alls thoughts?

[swissspidy]

Interesting suggestion!

Unfortunately the 10 minutes duration is hardcoded in wp_is_maintenance_mode(). Ideally this could be filterable/overridable somehow in core itself. A workaround could be to run wp maintenance-mode activate --force every minute or so, to keep extending the window.

With --manual, do you mean like manually providing a very high timestamp that will basically never expire? If so, I'd suggest something like --expiry instead which could support number of seconds or even any string parseable by strtotime() (e.g. wp maintenance-mode activate --expiry="+1 day").