??????? Original Message ??????? On Wednesday, April 10, 2019 10:24 PM, Aki Tuomi <aki.tuomi at open-xchange.com> wrote:> > On 10 April 2019 23:56 Laura Smith via dovecot < dovecot at dovecot.org> wrote: > > > > ??????? Original Message ??????? > > On Wednesday, April 10, 2019 9:14 PM, Aki Tuomi < aki.tuomi at open-xchange.com> wrote: > > > > > > On 10 April 2019 23:13 Laura Smith via dovecot dovecot at dovecot.org wrote: > > > > Sent with ProtonMail Secure Email. > > > > ??????? Original Message ??????? > > > > On Wednesday, April 10, 2019 8:20 PM, Aki Tuomi aki.tuomi at open-xchange.com wrote: > > > > > > > > > On 10 April 2019 22:13 Laura Smith via dovecot dovecot at dovecot.org wrote: > > > > > > On Wednesday, April 10, 2019 7:57 PM, Aki Tuomi aki.tuomi at open-xchange.com wrote: > > > > > > > > > > > > > On 10 April 2019 21:26 Laura Smith via dovecot dovecot at dovecot.org wrote: > > > > > > > > =========================================================================> > > > > > > > dsync( foobar at example.com): Error: imapc(foobar.example.com:993): dns_lookup(foobar.example.com) failed: read(/var/run/dovecot/dns-client) failed: read(size=512) failed: Connection reset by peer > > > > > > > > > > > > > This is dovecot's internal dns-client, and something goes wrong when talking to the service. > > > > > > > > > > > > > > dsync( foobar at example.com): Error: Failed to initialize user: imapc: Login to foobar.example.com failed: Disconnected from server > > > > > > > > > > > > > This is btw dsync service, not imap service. > > > > > > > > > > > > > > ==> > > > > > > > Initially I thought "oh no, not another AppArmor block". > > > > > > > > But then surely the second message would not appear if the DNS lookup was not successful ? > > > > > > > > Also "dig foobar.example.com" works fine. > > > > > > > > How should I be troubleshooting this ? And if it is still likely to be AppArmor, what is calling it ? "doveadm" itself or something else ? What does "/var/run/dovecot/dns-client" do and why doesn't dovecot use standard OS calls like everyone else ? > > > > > > > > > > > > > Because the "standard OS call" is blocking and we would prefer it to not block everything else. > > > > > > > > > > > > > > So many questions ! > > > > > > > > > > > > > Aki > > > > > > > > > > > Thanks for your reply, but both those message are generated from a simple : > > > > > > doveadm -v -o mail_fsync=never backup -R -u foobar at example.com imapc: > > > > > > So I don't know what you mean about dsync service failing ? Surely the DNS lookup succeeded if the 'dsync service' failed due to remote disconnect ? > > > > > > I'm still none the wiser as to where to start looking for troubleshoting ? > > > > > > > > > Did you check dovecot logs? Maybe there is something useful? > > > > > Aki > > > > > > > Only the same old cryptic message about dns-client ? > > > > master: Fatal: execv(/usr/lib/dovecot/dns-client) failed: Permission denied > > > > > Something prevents executing the dns-client binary. > > > > > > master: Error: service(dns_client): command startup failed, throttling for 16 secs > > > > dns_client: Fatal: master: service(dns_client): child 14293 returned error 84 (exec() failed) > > > > > Aki > > > > Yes but is it being called by doveadm directly or by some other dovecot program ? If I'm going to have to go down the AppArmor route, then I would prefer if you told me what was calling it instead of me having to un-necessarily spend time doing straces ! > > > > Also, should I be able to call dns-client directly myself ? (or is there a way to do so to enable testing ? > > It is started by dovecot's master process when you connect to dns-client unix socket. You can try > > socat stdio unix-connect:/var/run/dovecot/dns-client > > I thought apparmor tells when something is blocked into kernel log? have you checked dmesg? > > Apologies for your frustration.? > ---Yeah nothing in dmesg.? I'm still hunting around to find some log somewhere but so far silence. "socat stdio unix-connect:/var/run/dovecot/dns-client" runs but returns nothing. Is that expected ? When you say "dovecot's master process", so? doveadm sync talks to the master process ?? So in terms of apparmor I would therefore be looking at /usr/sbin/dovecot ?? If that's the case, the relevant apparmor permisssions are already provided : ? /{,var/}run/dovecot/ rw, ? /{,var/}run/dovecot/** rw,
On 11/04/2019 00:18, Laura Smith via dovecot wrote:> ??????? Original Message ??????? > On Wednesday, April 10, 2019 10:24 PM, Aki Tuomi <aki.tuomi at open-xchange.com> wrote: > >>> On 10 April 2019 23:56 Laura Smith via dovecot < dovecot at dovecot.org> wrote: >>> >>> ??????? Original Message ??????? >>> On Wednesday, April 10, 2019 9:14 PM, Aki Tuomi < aki.tuomi at open-xchange.com> wrote: >>> >>>>> On 10 April 2019 23:13 Laura Smith via dovecot dovecot at dovecot.org wrote: >>>>> Sent with ProtonMail Secure Email. >>>>> ??????? Original Message ??????? >>>>> On Wednesday, April 10, 2019 8:20 PM, Aki Tuomi aki.tuomi at open-xchange.com wrote: >>>>>>> On 10 April 2019 22:13 Laura Smith via dovecot dovecot at dovecot.org wrote: >>>>>>> On Wednesday, April 10, 2019 7:57 PM, Aki Tuomi aki.tuomi at open-xchange.com wrote: >>>>>>>>> On 10 April 2019 21:26 Laura Smith via dovecot dovecot at dovecot.org wrote: >>>>>>>>> =========================================================================>>>>>>>>> dsync( foobar at example.com): Error: imapc(foobar.example.com:993): dns_lookup(foobar.example.com) failed: read(/var/run/dovecot/dns-client) failed: read(size=512) failed: Connection reset by peer >>>>>>>> This is dovecot's internal dns-client, and something goes wrong when talking to the service. >>>>>>>>> dsync( foobar at example.com): Error: Failed to initialize user: imapc: Login to foobar.example.com failed: Disconnected from server >>>>>>>> This is btw dsync service, not imap service. >>>>>>>>> ==>>>>>>>>> Initially I thought "oh no, not another AppArmor block". >>>>>>>>> But then surely the second message would not appear if the DNS lookup was not successful ? >>>>>>>>> Also "dig foobar.example.com" works fine. >>>>>>>>> How should I be troubleshooting this ? And if it is still likely to be AppArmor, what is calling it ? "doveadm" itself or something else ? What does "/var/run/dovecot/dns-client" do and why doesn't dovecot use standard OS calls like everyone else ? >>>>>>>> Because the "standard OS call" is blocking and we would prefer it to not block everything else. >>>>>>>>> So many questions ! >>>>>>>> Aki >>>>>>> Thanks for your reply, but both those message are generated from a simple : >>>>>>> doveadm -v -o mail_fsync=never backup -R -u foobar at example.com imapc: >>>>>>> So I don't know what you mean about dsync service failing ? Surely the DNS lookup succeeded if the 'dsync service' failed due to remote disconnect ? >>>>>>> I'm still none the wiser as to where to start looking for troubleshoting ? >>>>>> Did you check dovecot logs? Maybe there is something useful? >>>>>> Aki >>>>> Only the same old cryptic message about dns-client ? >>>>> master: Fatal: execv(/usr/lib/dovecot/dns-client) failed: Permission denied >>>> Something prevents executing the dns-client binary. >>>>> master: Error: service(dns_client): command startup failed, throttling for 16 secs >>>>> dns_client: Fatal: master: service(dns_client): child 14293 returned error 84 (exec() failed) >>>> Aki >>> Yes but is it being called by doveadm directly or by some other dovecot program ? If I'm going to have to go down the AppArmor route, then I would prefer if you told me what was calling it instead of me having to un-necessarily spend time doing straces ! >>> >>> Also, should I be able to call dns-client directly myself ? (or is there a way to do so to enable testing ? >> It is started by dovecot's master process when you connect to dns-client unix socket. You can try >> >> socat stdio unix-connect:/var/run/dovecot/dns-client >> >> I thought apparmor tells when something is blocked into kernel log? have you checked dmesg? >> >> Apologies for your frustration.? >> --- > Yeah nothing in dmesg.? I'm still hunting around to find some log somewhere but so far silence. > > "socat stdio unix-connect:/var/run/dovecot/dns-client" runs but returns nothing. Is that expected ? > > When you say "dovecot's master process", so? doveadm sync talks to the master process ?? So in terms of apparmor I would therefore be looking at /usr/sbin/dovecot ?? If that's the case, the relevant apparmor permisssions are already provided : > ? /{,var/}run/dovecot/ rw, > ? /{,var/}run/dovecot/** rw,Laura Do the above apparmor settings give permission to dovecot to execute /usr/lib/dovecot/dns-client, assuming that the user under which dovecot is running already has file system permissions to do that? John
??????? Original Message ??????? On Wednesday, April 10, 2019 11:48 PM, John Fawcett via dovecot <dovecot at dovecot.org> wrote:> On 11/04/2019 00:18, Laura Smith via dovecot wrote: > > > ??????? Original Message ??????? > > On Wednesday, April 10, 2019 10:24 PM, Aki Tuomi aki.tuomi at open-xchange.com wrote: > > > > > > On 10 April 2019 23:56 Laura Smith via dovecot < dovecot at dovecot.org> wrote: > > > > ??????? Original Message ??????? > > > > On Wednesday, April 10, 2019 9:14 PM, Aki Tuomi < aki.tuomi at open-xchange.com> wrote: > > > > > > > > > > On 10 April 2019 23:13 Laura Smith via dovecot dovecot at dovecot.org wrote: > > > > > > Sent with ProtonMail Secure Email. > > > > > > ??????? Original Message ??????? > > > > > > On Wednesday, April 10, 2019 8:20 PM, Aki Tuomi aki.tuomi at open-xchange.com wrote: > > > > > > > > > > > > > > On 10 April 2019 22:13 Laura Smith via dovecot dovecot at dovecot.org wrote: > > > > > > > > On Wednesday, April 10, 2019 7:57 PM, Aki Tuomi aki.tuomi at open-xchange.com wrote: > > > > > > > > > > > > > > > > > > On 10 April 2019 21:26 Laura Smith via dovecot dovecot at dovecot.org wrote: > > > > > > > > > > > > > > > > > > > > =========================================================================> > > > > > > > > > > > > > > > > > > > dsync( foobar at example.com): Error: imapc(foobar.example.com:993): dns_lookup(foobar.example.com) failed: read(/var/run/dovecot/dns-client) failed: read(size=512) failed: Connection reset by peer > > > > > > > > > > This is dovecot's internal dns-client, and something goes wrong when talking to the service. > > > > > > > > > > dsync( foobar at example.com): Error: Failed to initialize user: imapc: Login to foobar.example.com failed: Disconnected from server > > > > > > > > > > This is btw dsync service, not imap service. > > > > > > > > > > > > > > > > > > > > ==============================================================================================================================================================================================================================================================================================================================================================================================================================================================================> > > > > > > > > > > > > > > > > > > > Initially I thought "oh no, not another AppArmor block". > > > > > > > > > > But then surely the second message would not appear if the DNS lookup was not successful ? > > > > > > > > > > Also "dig foobar.example.com" works fine. > > > > > > > > > > How should I be troubleshooting this ? And if it is still likely to be AppArmor, what is calling it ? "doveadm" itself or something else ? What does "/var/run/dovecot/dns-client" do and why doesn't dovecot use standard OS calls like everyone else ? > > > > > > > > > > Because the "standard OS call" is blocking and we would prefer it to not block everything else. > > > > > > > > > > So many questions ! > > > > > > > > > > Aki > > > > > > > > > > Thanks for your reply, but both those message are generated from a simple : > > > > > > > > > > doveadm -v -o mail_fsync=never backup -R -u foobar at example.com imapc: > > > > > > > > > > So I don't know what you mean about dsync service failing ? Surely the DNS lookup succeeded if the 'dsync service' failed due to remote disconnect ? > > > > > > > > > > I'm still none the wiser as to where to start looking for troubleshoting ? > > > > > > > > > > Did you check dovecot logs? Maybe there is something useful? > > > > > > > > > > Aki > > > > > > > > > > Only the same old cryptic message about dns-client ? > > > > > > > > > > master: Fatal: execv(/usr/lib/dovecot/dns-client) failed: Permission denied > > > > > > > > > > Something prevents executing the dns-client binary. > > > > > > > > > > master: Error: service(dns_client): command startup failed, throttling for 16 secs > > > > > > > > > > dns_client: Fatal: master: service(dns_client): child 14293 returned error 84 (exec() failed) > > > > > > > > > > Aki > > > > > > > > > > Yes but is it being called by doveadm directly or by some other dovecot program ? If I'm going to have to go down the AppArmor route, then I would prefer if you told me what was calling it instead of me having to un-necessarily spend time doing straces ! > > > > > > > > Also, should I be able to call dns-client directly myself ? (or is there a way to do so to enable testing ? > > > > It is started by dovecot's master process when you connect to dns-client unix socket. You can try > > > > > > socat stdio unix-connect:/var/run/dovecot/dns-client > > > I thought apparmor tells when something is blocked into kernel log? have you checked dmesg? > > > > > > Apologies for your frustration. > > > > > > -------------------------------- > > > > Yeah nothing in dmesg.? I'm still hunting around to find some log somewhere but so far silence. > > "socat stdio unix-connect:/var/run/dovecot/dns-client" runs but returns nothing. Is that expected ? > > When you say "dovecot's master process", so? doveadm sync talks to the master process ?? So in terms of apparmor I would therefore be looking at /usr/sbin/dovecot ?? If that's the case, the relevant apparmor permisssions are already provided : > > ? /{,var/}run/dovecot/ rw, > > ? /{,var/}run/dovecot/** rw, > > Laura > > Do the above apparmor settings give permission to dovecot to execute > /usr/lib/dovecot/dns-client, assuming that the user under which dovecot > is running already has file system permissions to do that? > > JohnJohn, Here's the definitive answer to your question (and anyone else thinking of pointing the finger at apparmor): foo:/home/foo # sudo systemctl stop apparmor foo:/home/foo # doveadm -v -o mail_fsync=never backup -R -u foobar at example.com imapc: dsync(foobar at example.com): Error: imapc(foobar.example.com:993): dns_lookup(foobar.example.com) failed: DNS lookup timed out dsync(foobar at example.com): Error: Failed to initialize user: imapc: Login to foobar.example.com failed: Disconnected from server So. Can we move on from the "blame apparmor" ? ;-)