Move bridge to an interim faster server

Background: [tor-project] More resources required for Snowflake bridge

I have or have been offered access to a faster server for the snowflake bridge. I anticipate being able to change DNS and start using the faster server on Wednesday, 2022-03-16.

The current situation is: I have control right now of a suitable paid server, and I have an offer of a suitable free server that I am supposed to get control of on Tuesday, 2022-03-15. I will prefer to switch to the free server, but if there are any unforeseen problems with that deal, the paid server will be ready as a backup.

I expect to have to move the bridge again, to a more permanent home, but not before 2022-03-21 (#40111 (closed)). The purpose of the migration in this ticket is to improve service until that other server is ready, and to mitigate any possible delays.

• install new bridge (installation guide), try 8 tor instances to start
• copy user accounts #40091 (comment 2768855)
• copy identity and onion keys from existing bridge
• copy HTTPS TLS keys and certificates from existing bridge
• test tor bootstrap on new bridge using local broker and proxy, and /etc/hosts domain name record #40095 (comment 2773365)
• make DNS for snowflake.torproject.net point to the new bridge tpo/tpa/team#40664 (closed)
• monitor for a day, be ready to switch DNS back if connections fail

Cc @art