Automatic configuration schema loading from database

[mmastrac]

Implements a DB schema to config generator. Since we cannot guarantee DB introspection in versions 6 and lower, we hard-code a config schema JSON blob as a fallback.

This library can also generate valid EdgeQL DDL for configuration changes.

Live DB schema introspection will be handled in the CLI.

TODO:

• Compress JSON?
• Docs
• Error tests

Example:

[branch.config]

# timeouts
session_idle_transaction_timeout     = "30 seconds"
query_execution_timeout              = "1 minute"

[instance.config]
http_max_connections                 = 100

[branch.config."cfg::Config"]
allow_user_specified_id              = true

[[branch.config.email_providers]]
_tname                = "cfg::SMTPProviderConfig"
name                  = "mailtrap-sandbox"
port                  = 2525
timeout_per_email     = "5 minutes"
timeout_per_attempt   = "1 minute"
validate_certs        = false

[[branch.config.'cfg::SMTPProviderConfig']]
port                  = 2525
name                  = "some-other-smtp-provider"
timeout_per_email     = "5 minutes"
timeout_per_attempt   = "1 minute"
validate_certs        = false


[[instance.config.auth]]
priority = 100
user = ["gel"]
method = { _tname = "cfg::JWT", transports = ["HTTP"] }

[[instance.config.auth]]
priority = 200
user = ["admin", "gel"]
method = { _tname = "cfg::SCRAM", transports = ["TCP", "HTTP"] }

Output:

configure instance set http_max_connections := <std::int64>100;
configure instance reset auth;
configure instance insert cfg::Auth {
    priority := <std::int64>100,
    user := {<std::str>'gel'},
    method := (insert cfg::JWT {
        transports := {<cfg::ConnectionTransport>'HTTP'}
    })
};
configure instance insert cfg::Auth {
    priority := <std::int64>200,
    user := {<std::str>'admin', <std::str>'gel'},
    method := (insert cfg::SCRAM {
        transports := {<cfg::ConnectionTransport>'TCP', <cfg::ConnectionTransport>'HTTP'}
    })
};
configure current database set allow_user_specified_id := <std::bool>true;
configure current database set query_execution_timeout := <std::duration>'1 minute';
configure current database set session_idle_transaction_timeout := <std::duration>'30 seconds';
configure current database reset email_providers;
configure current database insert cfg::SMTPProviderConfig {
    name := <std::str>'some-other-smtp-provider',
    port := <std::int32>2525,
    validate_certs := <std::bool>false,
    timeout_per_email := <std::duration>'5 minutes',
    timeout_per_attempt := <std::duration>'1 minute'
};
configure current database insert cfg::SMTPProviderConfig {
    name := <std::str>'mailtrap-sandbox',
    port := <std::int32>2525,
    validate_certs := <std::bool>false,
    timeout_per_email := <std::duration>'5 minutes',
    timeout_per_attempt := <std::duration>'1 minute'
};