preliminary imap server implementation

It shares a bit of code with NNTP.  It's copy+pasted for now
since this provides new ground to experiment with APIs for
dealing with slow storage and many inboxes.

1 files changed, 91 insertions, 0 deletions

diff --git a/Documentation/public-inbox-imapd.pod b/Documentation/public-inbox-imapd.pod
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+=head1 NAME
+
+public-inbox-imapd - IMAP server for sharing public-inboxes
+
+=head1 SYNOPSIS
+
+B<public-inbox-imapd> [OPTIONS]
+
+=head1 DESCRIPTION
+
+public-inbox-imapd provides a read-only IMAP daemon for
+public-inbox.  It uses options and environment variables common
+to all L<public-inbox-daemon(8)> implementations.
+
+Like L<public-inbox-nntpd(1)> and L<public-inbox-httpd(1)>,
+C<public-inbox-imapd> will never require write access
+to the directory where the public-inboxes are stored, so it
+may be run as a different user than the user running
+L<public-inbox-watch(1)>, L<public-inbox-mda(1)>, or
+L<git-fetch(1)>.
+
+=head1 OPTIONS
+
+See common options in L<public-inbox-daemon(8)/OPTIONS>.
+Additionally, IMAP-specific behavior for certain options
+are supported and documented below.
+
+=over
+
+=item -l, --listen PROTO://ADDRESS/?cert=/path/to/cert,key=/path/to/key
+
+In addition to the normal C<-l>/C<--listen> switch described in
+L<public-inbox-daemon(8)>, the C<PROTO> prefix (e.g. C<imap://> or
+C<imaps://>) may be specified to force a given protocol.
+
+For STARTTLS and IMAPS support, the C<cert> and C<key> may be specified
+on a per-listener basis after a C<?> character and separated by C<,>.
+These directives are per-directive, and it's possible to use a different
+cert for every listener.
+
+=item --cert /path/to/cert
+
+The default TLS certificate for optional STARTTLS and IMAPS support
+if the C<cert> option is not given with C<--listen>.
+
+If using systemd-compatible socket activation and a TCP listener on port
+993 is inherited, it is automatically IMAPS when this option is given.
+When a listener on port 143 is inherited and this option is given, it
+automatically gets STARTTLS support.
+
+=item --key /path/to/key
+
+The default private TLS certificate key for optional STARTTLS and IMAPS
+support if the C<key> option is not given with C<--listen>.  The private
+key may concatenated into the path used by C<--cert>, in which case this
+option is not needed.
+
+=back
+
+=head1 CONFIGURATION
+
+C<public-inbox-imapd> uses the same configuration knobs
+as L<public-inbox-nntpd(1)>, see L<public-inbox-nntpd(1)>
+and L<public-inbox-config(5)>.
+
+=over 8
+
+=item publicinbox.<name>.newsgroup
+
+The newsgroup name maps to an IMAP folder name.
+
+=back
+
+=head1 CONTACT
+
+Feedback welcome via plain-text mail to L<mailto:meta@public-inbox.org>
+
+The mail archives are hosted at L<https://public-inbox.org/meta/>,
+L<nntp://news.public-inbox.org/inbox.comp.mail.public-inbox.meta>,
+L<nntp://hjrcffqmbrq6wope.onion/inbox.comp.mail.public-inbox.meta>
+
+=head1 COPYRIGHT
+
+Copyright 2020 all contributors L<mailto:meta@public-inbox.org>
+
+License: AGPL-3.0+ L<https://www.gnu.org/licenses/agpl-3.0.txt>
+
+=head1 SEE ALSO
+
+L<git(1)>, L<git-config(1)>, L<public-inbox-daemon(8)>,
+L<public-inbox-config(5)>, L<public-inbox-nntpd(1)>