Meta: Make distributed deployments possible

[foxcpp]

In the light of #277 and Project Hexanet's internal needs. Here is the list of things to do:

• Migrate to go-imap v2 #259

Refactoring:

• Refactor imapsql blob storage interface to use modules framework #303
• Replace updatepipe package written for go-imap v1 with a better update dispatcher.
• Implement support for some distributed broker - to be used with IMAP updates distribution.
• Create abstraction for SMTP queue storage #262.
• S3 blob storage #304

Several queries should be optimized/reworked in go-imap-sql in order to behave well in a distributed environment:

• Get rid of "marking" logic in message removal go-imap-sql#28
• Expunge does two (!) full table scans go-imap-sql#33

Officially support CockroachDB:

• CockroachDB support go-imap-sql#5
• Officially support CockroachDB use with auth.sql_table/auth.sql_query.

In other words, we have a long way to go. :)

[savchenko]

Is this relevant to #473 by any chance?..

[foxcpp]

Yes, it is directly related. Currently, maddy does but support any deployment setup using active replication. For MX redundancy, your best solution is to configure second MX to buffer incoming messages and attempt resending them to the main server infinitely.

[aviallon]

Yes, it is directly related. Currently, maddy does but support any deployment setup using active replication. For MX redundancy, your best solution is to configure second MX to buffer incoming messages and attempt resending them to the main server infinitely.

Is there any hidden documentation on how to configure go-imap-sql with maddy?

I plan to setup a test server, which I'll migrate to when I feel the project is mature enough (I'm tired of dovecot).

[foxcpp]

go-imap-sql is storage.imapsql module in maddy. All relevant documentation is available here: https://maddy.email/reference/storage/imapsql/
Some additional (mostly technical) information is available here: https://github.com/foxcpp/go-imap-sql

[foxcpp]

I'll migrate to when I feel the project is mature enough

As of that, go-imap-sql will be eventually replaced by https://github.com/foxcpp/maddy-storage that is is in early development stage currently.