The new option `services.prometheus.enableReload` has been introduced
which, when enabled, causes the prometheus systemd service to reload
when its config file changes.
More specifically the following property holds: switching to a
configuration (`switch-to-configuration`) that changes the prometheus
configuration only finishes successully when prometheus has finished
loading the new configuration.
`enableReload` is `false` by default in which case the old semantics
of restarting the prometheus systemd service are in effect.
The parentheses prevent the `continue` line from working by running the
enclosed in a subshell -- I noticed that ZFS would start asking me for
my password to encrypted child datasets, even though they were not
specified in `requestEncryptionCredentials`. The following logs would
also be present in the import unit's journal:
Oct 31 22:13:17 host systemd[1]: Starting Import ZFS pool "pool"...
Oct 31 22:13:44 host zfs-import-pool-start[3711]: importing ZFS pool "pool"...
Oct 31 22:13:44 host zfs-import-pool-start[4017]:pool/nix/store/39zij3xcxn4w38v6x8f88bx8y91nv0rm-unit-script-zfs-import-pool-start/bin/zfs-import-pool-start: line 31: continue: only meaningful in a `for', `while', or `until' loop
Oct 31 22:13:44 host zfs-import-pool-start[4020]:pool/nix/store/39zij3xcxn4w38v6x8f88bx8y91nv0rm-unit-script-zfs-import-pool-start/bin/zfs-import-pool-start: line 31: continue: only meaningful in a `for', `while', or `until' loop
Oct 31 22:15:14 host zfs-import-pool-start[4023]: Failed to query password: Timer expired
Oct 31 22:15:14 host zfs-import-pool-start[4024]: Key load error: encryption failure
Oct 31 22:15:14 host systemd[1]: zfs-import-pool.service: Main process exited, code=exited, status=255/EXCEPTION
Oct 31 22:15:14 host systemd[1]: zfs-import-pool.service: Failed with result 'exit-code'.
Oct 31 22:15:14 host systemd[1]: Failed to start Import ZFS pool "pool".
Details on https://github.com/NixOS/nixops/issues/1063#issuecomment-453253666.
`partOf` makes that if `smokeping.service` is stopped, `thttpd.service` will
be stopped as well.
(But not that `thttpd` will be started when `smokeping` is started).
Once `thttpd.service` is stopped that way, `Restart = always` will not apply.
When the smokeping config options are changed, NixOS's `switch-configuration.pl`
will stop `smokeping` (whit shuts down thttpd due to `partOf`), and then restart
smokeping; but this does not start thttpd.
As a result, thttpd will be off after changing the config, which isn't desired.
This commit fixes it by removing the `partOf`, which makes `Restart` work
as expected.
This avoids a common problem:
Until now, port forwarding to multiple hosts running smokeping did not work;
they all show the data of the first smokeping instance.
That ws because the image URLs generated by smokeping are absolute
(`imgurl` setting).
Consequently, if you ran
ssh node-1 -L 8081:localhost:8081
ssh node-2 -L 8081:localhost:8082
ssh node-3 -L 8081:localhost:8083
and try to open http://localhost:8081, http://localhost:8082 and
http://localhost:8083, they all would show the images of node-1!
Using a relative `imgurl` fixes that.
As per smokeping docs on `imgurl`:
> Either an absolute URL to the `imgcache` directory or one relative to the
> directory where you keep the SmokePing cgi.
qemu_kvm is only built for one architecture, so it's smaller and takes
MUCH less time to build if it has to be built from source. And this
module doesn't support running a VM for one architecture from another
architecture, so the one architecture is all we'll need.
