Docker containers don't log like normal linux distos do with syslog/rsyslog/syslog-ng/etc. They expect the main process to output all logging to STDOUT, this is recorded as "log" output by the docker daemon.
You may need to set the "maillog_file" postfix config option to "/dev/stdout", thus redirect all logging to STDOUT for docker to read. This is my first post to this mailing list, so hi! On Mon, 12 Dec 2022 04:11:06 +0400 Sam <lis...@afach.de> wrote: > Dear experts in postfix: > > > I've been having different kinds of issues in postfix when moving my email > server into docker containers (which I know some don't recommend, but please > tolerate that as I have trade-offs to make). In my test setup where I'm > experimenting, I copied all the configuration I already have in bare-metal > into the container (and changed some of it, like paths, and used lmtp instead > of lda), copied some test emails in there, and launched separate containers > for postfix, dovecot, opendkim and mariadb. In previous email to this email > list I was trying to do haproxy SSL/TLS termination, but I gave that up (for > now) because I also failed at debugging what's going on for the same reason > I'm writing this email: > > > **I really can't debug any smtp issues whatsoever.** > > > My postfix container is based on Debian 11, where I install postfix with apt > and then launch `postfix start-fg`. > > > Btw, networking to containers is bridges automatically created by > docker-compose. Most communication is done with inet, and some are done with > unix-socket files across containers (most of which I plan to change to inet > later, ... one step at a time), in case someone is wondering. > > > When I launch my containers with docker-compose, I can see logs from dovecot > and mariadb. I see logs of postfix ONLY if some configuration is incorrect. > It can say things like "this configuration line isn't used", and so on. But > nothing during operation whatsoever. The directory /var/log/ in the container > has nothing in it related to postfix. There's literally zero logging all in > all. > > > To test my setup, I tunnel with ssh to my server, and then use a fresh > Thunderbird installation on the same test computer to add 127.0.0.1 as email > server (which passes through the tunnel to my server). The initial > authentication works fine for both IMAP and SMTP. Also downloading emails > with dovecot works fine. But sending emails with postfix always fails with > the error: "The mail server responded: <u...@example.com>: Temporary lookup > failure. Please check the message recipient "u...@example.com" and try again. > > > I'm happy to pursue the error myself, but all my attempts to log any useful > information has failed. I added in main.cf the lines (and I use wildcard for > all IPv4 addresses because this is all a test setup before this becomes > serious): > > > debug_peer_list=0.0.0.0/0 > debug_peer_level=6 > > > and in master.cf, I added `-v` flag on smtpd. Nothing comes out of it. Zero > logging to both stdout and /var/log/. > > > When attempting to send an email (which fails like I mentioned), I can see > the process of smtpd launched with the command (using ps -ax): > > > postfix 1457 1.5 0.0 44652 10632 ? S 23:24 0:00 smtpd -n > submission -t inet -u -o stress= -v -o smtpd_tls_security_level=encrypt -o > smtpd_enforce_tls=yes -o smtpd_sasl_auth_enable=yes -o > smtpd_client_restrictions=permit_mynetworks,permit_sasl_authenticated,reject > > > and I tried moving that `-v` around to the end of everything... no use. I > can't get a single line of actions logged. Why? What am missing? How can I > get postfix to tell me what's going on step by step in its failure? > > > Thank you and best regards, > > Sam
