Rudy Broersma wrote:
> On our machine with Debian Stretch with all updates (as of 2015/12/05) we
> noticed
> that sometimes unbound failed to start. I believe this has something to do
> with unbound-control and systemctl.
> * Outcome in our test case:
> - Systemctl is unable to start unbound when it wasn't stopped by systemctl
> but by unbound-control.
>
> * Expected outcome:
>
> - Systemctl to start unbound, regardless of how it was stopped.
Hi, Rudy:
It looks like this behavior is caused by the fact that the unbound
package doesn't ship a systemd service unit. Therefore, the
systemd-sysv-generator automatically generates a unit file that looks
like this:
# Automatically generated by systemd-sysv-generator
[Unit]
Documentation=man:systemd-sysv-generator(8)
SourcePath=/etc/init.d/unbound
Before=multi-user.target multi-user.target multi-user.target
graphical.target shutdown.target
After=network-online.target remote-fs.target systemd-journald-dev-log.socket
Wants=network-online.target
Conflicts=shutdown.target
[Service]
Type=forking
Restart=no
TimeoutSec=5min
IgnoreSIGPIPE=no
KillMode=process
GuessMainPID=no
RemainAfterExit=yes
ExecStart=/etc/init.d/unbound start
ExecStop=/etc/init.d/unbound stop
ExecReload=/etc/init.d/unbound reload
Note the "RemainAfterExit=yes". According to systemd.service(5):
RemainAfterExit=
Takes a boolean value that specifies whether the service shall be
considered active even when all its processes exited. Defaults to
no.
That appears to be causing the behavior that you observed when running
"unbound-control stop".
Testing a very basic native unbound.service unit file:
[Unit]
Description=Unbound DNS server
After=network.target
Before=nss-lookup.target
Wants=nss-lookup.target
[Service]
Type=simple
EnvironmentFile=-/etc/default/unbound
ExecStart=/usr/sbin/unbound -d $DAEMON_OPTS
ExecReload=/usr/sbin/unbound-control reload
[Install]
WantedBy=multi-user.target
I get the following behavior when running your test commands:
root@debian:~# systemctl status unbound.service
● unbound.service - Unbound DNS server
Loaded: loaded (/etc/systemd/system/unbound.service; enabled; vendor
preset: enabled)
Drop-In: /run/systemd/generator/unbound.service.d
└─50-insserv.conf-$named.conf, 50-unbound-$named.conf
Active: active (running) since Sat 2016-01-23 23:32:42 UTC; 5s ago
Main PID: 7849 (unbound)
CGroup: /system.slice/unbound.service
└─7849 /usr/sbin/unbound -d
Jan 23 23:32:42 debian systemd[1]: Started Unbound DNS server.
Jan 23 23:32:42 debian unbound[7849]: [7849:0] notice: init module 0:
validator
Jan 23 23:32:42 debian unbound[7849]: [7849:0] notice: init module 1:
iterator
Jan 23 23:32:42 debian unbound[7849]: [7849:0] info: start of service
(unbound 1.5.7).
root@debian:~# unbound-control stop
ok
root@debian:~# systemctl status unbound.service
● unbound.service - Unbound DNS server
Loaded: loaded (/etc/systemd/system/unbound.service; enabled; vendor
preset: enabled)
Drop-In: /run/systemd/generator/unbound.service.d
└─50-insserv.conf-$named.conf, 50-unbound-$named.conf
Active: inactive (dead) since Sat 2016-01-23 23:33:20 UTC; 3s ago
Process: 7849 ExecStart=/usr/sbin/unbound -d $DAEMON_OPTS (code=exited,
status=0/SUCCESS)
Main PID: 7849 (code=exited, status=0/SUCCESS)
Jan 23 23:32:42 debian systemd[1]: Started Unbound DNS server.
Jan 23 23:32:42 debian unbound[7849]: [7849:0] notice: init module 0:
validator
Jan 23 23:32:42 debian unbound[7849]: [7849:0] notice: init module 1:
iterator
Jan 23 23:32:42 debian unbound[7849]: [7849:0] info: start of service
(unbound 1.5.7).
Jan 23 23:33:20 debian unbound[7849]: [7849:0] info: service stopped
(unbound 1.5.7).
Jan 23 23:33:20 debian unbound[7849]: [7849:0] info: server stats for
thread 0: 0 queries, 0 answers from cache, 0 recursions,...refetch
Jan 23 23:33:20 debian unbound[7849]: [7849:0] info: server stats for
thread 0: requestlist max 0 avg 0 exceeded 0 jostled 0
Hint: Some lines were ellipsized, use -l to show in full.
root@debian:~# systemctl start unbound.service
root@debian:~# systemctl status unbound.service
● unbound.service - Unbound DNS server
Loaded: loaded (/etc/systemd/system/unbound.service; enabled; vendor
preset: enabled)
Drop-In: /run/systemd/generator/unbound.service.d
└─50-insserv.conf-$named.conf, 50-unbound-$named.conf
Active: active (running) since Sat 2016-01-23 23:33:35 UTC; 2s ago
Main PID: 7857 (unbound)
CGroup: /system.slice/unbound.service
└─7857 /usr/sbin/unbound -d
Jan 23 23:33:35 debian systemd[1]: Started Unbound DNS server.
Jan 23 23:33:35 debian unbound[7857]: [7857:0] notice: init module 0:
validator
Jan 23 23:33:35 debian unbound[7857]: [7857:0] notice: init module 1:
iterator
Jan 23 23:33:35 debian unbound[7857]: [7857:0] info: start of service
(unbound 1.5.7).
This looks like the correct behavior, so I will mark this bug resolved
for the next upload that adds native systemd unit files.
Thanks for the report!
--
Robert Edmonds
edmo...@debian.org
