I'm migrating an old server to another old server (same dovecot version in both servers) The migration itself is straightforward, stop dovecot on the old server, migrate everything via rsync, start dovecot to the new server. There is only one step left: change the dns configuration, pointing from the old server to the newer one. As most of domains are not managed by me and some other domains are pointing to our server via IP, I can't simply change the A record or wait for all users to change their domain configuration. TL;DR: is possible to use dovecot as IMAP proxy so that even after changing our dns records, any user directly connecting to my old server would be proxied to the newer one automatically ? Any additional software or only a configuration change is required ?
> On December 15, 2017 at 6:57 PM Gandalf Corvotempesta <gandalf.corvotempesta at gmail.com> wrote: > > > I'm migrating an old server to another old server (same dovecot > version in both servers) > The migration itself is straightforward, stop dovecot on the old > server, migrate everything via rsync, start dovecot to the new server. > > There is only one step left: change the dns configuration, pointing > from the old server to the newer one. > As most of domains are not managed by me and some other domains are > pointing to our server via IP, I can't simply change the A record or > wait for all users to change their domain configuration. > > TL;DR: is possible to use dovecot as IMAP proxy so that even after > changing our dns records, any user directly connecting to my old > server would be proxied to the newer one automatically ? > > Any additional software or only a configuration change is required ?Return from passdb, 'proxy host=your-new-host port=143 ssl=starttls' Aki
On Fri, December 15, 2017 3:21 pm, Aki Tuomi wrote:> >> On December 15, 2017 at 6:57 PM Gandalf Corvotempesta >> <gandalf.corvotempesta at gmail.com> wrote: >> >>...>> server would be proxied to the newer one automatically ? >> >> Any additional software or only a configuration change is required ? > > Return from passdb, 'proxy host=your-new-host port=143 ssl=starttls' > > Aki >Or masquerade all traffic to the new server with firewall rules: iptables -t nat -A PREROUTING -i ethX -p tcp -m tcp --dport 143 -j DNAT --to-destination 1.1.1.1 iptables -t nat -A POSTROUTING -d 1.1.1.1/32 -p tcp -m tcp --dport 143 -j MASQUERADE ethX --> interface where connections come from 1.1.1.1 --> new server IP address Maybe smth is wrong up there, didnt tested, but I think its cool. cheers. -- x9p | PGP : 0x03B50AF5EA4C8D80 / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
2017-12-15 18:21 GMT+01:00 Aki Tuomi <aki.tuomi at dovecot.fi>:> Return from passdb, 'proxy host=your-new-host port=143 ssl=starttls'So, instead of returning the current db output: "user, password, userdb_mail, userdb_sieve, ......" is enough to only return "proxy host=your-new-host port=143 ssl=starttls" ? Will dovecot automatically proxy pop3/imap on the new server ? What about LDA ?