rebase

add backup window

review feedback

addressed apostrophes and unneeded newline in latest rebase

typo. accidental uppercase

review feedback

rebase

review feedback

switch around

review feedback

update latest version to block on with default

review feedback

feedback

rebase

review feedback

Looks good to me. There shouldn't be any issues with load balancer health checks correct?

There's another possible solution I didn't think of until now. We can possibly fork non-master processes earlier than the migration, start their express servers with only health checks, and then stall? This would have the added benefit of having multiple processes handling health check requests. Unsure if this is feasible or more desirable than my current solution

In D13172#373294, @ashoat wrote:

It's unclear to me why you need to stop the Express server at all. Why not take a similar approach to D13213?

In D13213#373288, @ashoat wrote:

In D13172, you had to stop the Express server after starting it, which forced you to introduce a new dependency (stoppable). Why was that not necessary here?

In D13209#372882, @varun wrote:

if a dev is introducing a new migration how will they know which migrationType variant to use? can we instead introduce an optional field in Migration to override the default behavior?

review feedback

This is no long necessary as we don't need to grab the new keyserver image through a script

Abandoning this revision. With our new approach of using JS based logic to block secondary nodes during migrations, this logic is no longer necessary in the deploy script.

add flow typing

Still needs flow typing

use stoppable instead

Unfortunately, hanging connections prevents the keyserver express server from properly listening and accepting traffic