My snap (hw-wtdog) having an app of type simple daemon, stays disabled (Startup) and inactive (Current) after installation.
snap info snippet
services:
hw-wtdog.runner: simple, disabled, inactive
root@localhost:# snap servicesService Startup Current Notesapp-mgr.app-mgr enabled active -hw-wtdog.runner disabled inactive - --> Problemtic snap
When I try to enable the snap, I get an error already enabled
root@localhost:~# snap enable hw-wtdogerror: cannot enable "hw-wtdog": snap "hw-wtdog" already enabledroot@localhost:~#
Finally, on starting the snap, status changes to active and service starts
root@localhost:# snap servicesService Startup Current Notesapp-mgr.app-mgr enabled active -hw-wtdog.runner disabled active -
snapcraft.yaml snippet
apps:
runner:
command: bin/setpet
daemon: simple
restart-condition: always
plugs: [snapd-control]
environment:
LD_LIBRARY_PATH: $SNAP/lib;
Not sure why other snaps that I have do not have this issue.
ogra
July 1, 2020, 8:11am
2
thats your issue … you are not trying to enable a snap but a service
snap start --enable hw-wtdog.runner
(instead of “snap enable …”)
though i’d recommend watching the journal to find out why it didnt start in the first place …
Right. But why should I need to enable service of a snap manually in first place? I am expecting that like other snap’s, service of this snap to start when snap gets installed.
I reinstalled the snap this time with journalctl running on one more terminal. But it does not give anything
root@localhost:# snap install hw-wtdog_0.27-0.1_amd64.snap --devmode
hw-wtdog 0.27-0.1 installed
root@localhost:
user@localhost:~$ sudo journalctl --output=short --follow --all | sudo snappy-debug -r
kernel.printk_ratelimit = 0
ogra
July 1, 2020, 10:26am
4
because the packager was cleverer than others and made sure that the service only starts once all interfaces it needs are connected ?
… or just because it is broken
i.e. take a look at the set of hooks here:
https://github.com/ogra1/pi-fancontrol-snap/tree/master/snap/hooks
by default the service comes up disabled … because it needs two interfaces to function … so instead of having it enabled and dieing in a loop (spamming logs) it stays disabled until both interface connections are there …
In my case, not all the interfaces (snapd-control) were connected. So I connected them and started the service manually. Then reinstalled the same snap again hoping this time the service will start. But it did not.
I am starting to believe this
Apart from snapd-control are there any other interfaces required for setting system watchdog (runtime and shutdown) timeouts? I tried adding hardware-observe but still did not work.
ogra
July 1, 2020, 1:39pm
6
i dont think so, snapd-control should be sufficient to give you access to the API equivalent of “snap set/get” … if the app is yours, just add some debugging code and watch your journal (and i mean not via snappy-debug but literally the syslog output there)…
I do have debug logs. But they are not getting printed.
Problematic snap has this logs while running snap install:
Jul 01 13:59:18 localhost systemd[1]: Stopping Service for snap application -hw-wtdog.runner...
Jul 01 13:59:18 localhost systemd[1]: Stopped Service for snap application -hw-wtdog.runner.
Jul 01 13:59:20 localhost systemd[1]: Reloading.
Jul 01 13:59:21 localhost audit[3177]: AVC apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/snapd/8140/usr/lib/snapd/snap-confine" pid=3177 comm="apparmor_parser"
Jul 01 13:59:21 localhost audit[3177]: AVC apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/snapd/8140/usr/lib/snapd/snap-confine//mount-namespace-capture-helper" pid=3177 comm="apparmor_parser"
Jul 01 13:59:21 localhost kernel: audit: type=1400 audit(1593611961.402:1611): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/snapd/8140/usr/lib/snapd/snap-confine" pid=3177 comm="apparmor_parser"
Jul 01 13:59:21 localhost kernel: audit: type=1400 audit(1593611961.402:1612): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/snapd/8140/usr/lib/snapd/snap-confine//mount-namespace-capture-helper" pid=3177 comm="apparmor_parser"
Jul 01 13:59:21 localhost audit[3179]: AVC apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.-hw-wtdog.runner" pid=3179 comm="apparmor_parser"
Jul 01 13:59:21 localhost kernel: audit: type=1400 audit(1593611961.598:1613): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.-hw-wtdog.runner" pid=3179 comm="apparmor_parser"
Jul 01 13:59:21 localhost audit[3181]: AVC apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="snap-update-ns.-hw-wtdog" pid=3181 comm="apparmor_parser"
Jul 01 13:59:21 localhost kernel: audit: type=1400 audit(1593611961.602:1614): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="snap-update-ns.-hw-wtdog" pid=3181 comm="apparmor_parser"
Jul 01 13:59:22 localhost systemd[1]: Reloading.
Jul 01 13:59:26 localhost systemd-udevd[499]: Network interface NamePolicy= disabled on kernel command line, ignoring.
Jul 01 13:59:26 localhost systemd[1]: Reloading.
Another working snap has this:
Jul 01 13:51:01 localhost systemd[1]: Reloading.
Jul 01 13:51:01 localhost systemd[1]: Mounting Mount unit for -app-mgr, revision x174...
Jul 01 13:51:01 localhost systemd-udevd[499]: Network interface NamePolicy= disabled on kernel command line, ignoring.
Jul 01 13:51:02 localhost systemd[1]: Mounted Mount unit for -app-mgr, revision x174.
Jul 01 13:51:02 localhost systemd[1]: Stopping Service for snap application app-mgr.app-mgr...
Jul 01 13:51:02 localhost -app-mgr.app-mgr[1752]: 2020/07/01 13:51:02: am_mqtt_offline_cb(44): am_mqtt_offline_cb 0
Jul 01 13:51:02 localhost -mosquitto.mosquitto[906]: 1593611462: Socket error on client am, disconnecting.
Jul 01 13:51:02 localhost systemd[1]: Stopped Service for snap application app-mgr.app-mgr.
Jul 01 13:51:03 localhost snapd[949]: response.go:368: cannot stream response; problem writing: write unix /run/snapd.socket->@: write: broken pipe
Jul 01 13:51:04 localhost systemd[1]: Reloading.
Jul 01 13:51:06 localhost snapd[949]: spec.go:175: renaming mount entry for directory "/snap/app-mgr/x174/-lib" to "/snap/-app-mgr/x174/-lib-2" to avoid a clash
Jul 01 13:51:06 localhost audit[2465]: AVC apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/snapd/8140/usr/lib/snapd/snap-confine" pid=2465 comm="apparmor_parser"
Jul 01 13:51:06 localhost audit[2465]: AVC apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/snapd/8140/usr/lib/snapd/snap-confine//mount-namespace-capture-helper" pid=2465 comm="apparmor_parser"
Jul 01 13:51:06 localhost kernel: audit: type=1400 audit(1593611466.206:1596): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/snapd/8140/usr/lib/snapd/snap-confine" pid=2465 comm="apparmor_parser"
Jul 01 13:51:06 localhost kernel: audit: type=1400 audit(1593611466.206:1597): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/snapd/8140/usr/lib/snapd/snap-confine//mount-namespace-capture-helper" pid=2465 comm="apparmor_parser"
Jul 01 13:51:06 localhost audit[2467]: AVC apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap-update-ns.-app-mgr" pid=2467 comm="apparmor_parser"
Jul 01 13:51:06 localhost kernel: audit: type=1400 audit(1593611466.286:1598): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap-update-ns.app-mgr" pid=2467 comm="apparmor_parser"
Jul 01 13:51:06 localhost audit[2468]: AVC apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.app-mgr.app-mgr" pid=2468 comm="apparmor_parser"
Jul 01 13:51:06 localhost kernel: audit: type=1400 audit(1593611466.490:1599): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.app-mgr.app-mgr" pid=2468 comm="apparmor_parser"
Jul 01 13:51:06 localhost audit[2469]: AVC apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.app-mgr.launch" pid=2469 comm="apparmor_parser"
Jul 01 13:51:06 localhost kernel: audit: type=1400 audit(1593611466.494:1600): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.app-mgr.launch" pid=2469 comm="apparmor_parser"
Jul 01 13:51:06 localhost systemd[1]: Reloading.
Jul 01 13:51:09 localhost systemd[1]: Started Service for snap application app-mgr.app-mgr.
Jul 01 13:51:10 localhost audit[2493]: AVC apparmor="ALLOWED" operation="capable" info="optional: no audit" error=-1 profile="snap.-app-mgr.app-mgr" pid=2493 comm="snap-exec" capability=12 capname="net_admin"
Jul 01 13:51:10 localhost kernel: audit: type=1400 audit(1593611470.006:1601): apparmor="ALLOWED" operation="capable" info="optional: no audit" error=-1 profile="snap.app-mgr.app-mgr" pid=2493 comm="snap-exec" capability=12 capname="net_admin"
Jul 01 13:51:11 localhost systemd-udevd[499]: Network interface NamePolicy= disabled on kernel command line, ignoring.
ogra
July 1, 2020, 2:05pm
8
well, make it log directly to a txt file in $SNAP_DATA worst case … from the app code …
Tried. Writing to a log file in $SNAP_DATA, but log file seen there only after i do snap start ....
While digging through https://snapcraft.io/docs/service-management came across - snap start --enable <snap>.<service>
Ran the command and rebooted. Voila !!! Service becomes active on next boot.
Although I don’t recall running snap start --disable<snap>.<service> on my device, --enable has solved the issue.
Thanks @ogra for your inputs.
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