The `/etc/collectd.d` directory is created by the RPM package on
machines running a Red Hat-based Linux distribution, but it may not
always be present on other machines.
In addition to ignoring particular types of filesystems, e.g. OverlayFS,
we can also ignore filesystems by their mount point. This could be
useful, for example, for bind-mounted directories, such as those used on
Kubernetes nodes.
By default, the *df* pluggin for collectd, which monitors filesystem
usage, collects data about all mounted filesystems. It can be
configured to ignore some filesystems, either by mount point, device, or
filesystem type. We will uses this capability to avoid collecting data
about OverlayFS mounts, because by definition, they do not represent a
real filesystem, but one or more other mounted filesystems. Collecting
data about these just creates useless metrics, especially on machines
that run containers.
Some machines, such as the nodes in the Kubernetes cluster, do not use
*firewalld*. For these machines, we need to skip the `firewalld` tasks,
as they will fail. The `host_uses_firewalld` variable can be set to
`False` for these machines to do so.
*nvr1.pyrocufflink.blue* is the new video recording server. It is a
1U rack-mounted physical machine based on the [Jetway
JBC150F596-3160-B][0] barebone system. It replaces
*nvr0.pyrocufflink.blue* in this role.
[0]: https://www.jetwaycomputer.com/JBC150F596.html
Podman 4 puts lock files in the configuration directory for [some stupid
reason][0]. There are so many issues here!
* It is now impossible to run `podman` as root with a read-only `/etc`.
* Why does it need the lock file at all when using `--network=host`?
Luckily, we can work around it fairly easily by mounting a tmpfs
filesystem over the directory it wants to put the lock file in. This
pretty much defeats the purpose of having a lock file, but it's likely
not needed anyway.
[0]: 836fa4c493
The *sensors* plugin for collectd reads temperature information from the
I²C/SMBus using *lm_sensors*. Naturally, it is only useful on physical
machines, so it is not installed or enabled by default.
Instead of a simple list of disabled plugins, hosts and host groups can
now control whether plugins are enabled or disabled using the
`collectd_plugins` map. The map keys are plugin names, and the values
are booleans indicating if the plugin is enabled.
Using this mechanism, some plugins can be disabled by default (e.g. the
*md* plugin), and enabling them per host or per host group is simpler.
Mosquitto can save retained messages, persistent clients, etc. to the
filesystem and restore them at startup. This allows state to be
maintained even after the process restarts.
The KDC service, as managed by Samba, continuously logs to two files
that need to be rotated. The upstream configuration for logrotate only
manages one of these files, and does not correctly signal the service
after rotating, as it expects the service to be managed by systemd
instead of Samba. As such, we need to adjust the configuration to
handle both files and send SIGHUP directly to the process.
Promoting the new site I have been working on at *dustin.hatch.is* to my
main domain, *dustin.hatch.name*. The new site is just static content,
generated and uploaded by a Jenkins job.
Finally have a certificate for *dustin.hatch.name* now, too!
This resolves two issues with fetching the Proton VPNserver list:
1. If a connection error occurs when fetching the list, it will be
ignored, just as with HTTP errors
2. If any errors are encountered when fetching the list, and a valid
cache was loaded, its contents are returned, regardless of the
timestamp of the cache file.
To handle the RSVP form on *dustinandtabitha.com*, we are going to use
*formsubmit*. It runs on the same machine that hosts the website, so
there's no dealing with CORS. The */submit/rsvp* path, which is proxied
to the backend, is the RSVP form's target.
*formsubmit* is a simple, customizable HTML for submission handler. I
designed it for Tabitha to use to collect information from forms on her
websites. Notably, we will use it for the RSVP page on our wedding
invitation site.
The state history database is entirely too big. It takes over an hour
to create a backup of it, which usually causes BURP to time out. The
data it stores isn't particularly interesting anyway. Instead of trying
to back it up and ultimately not getting any backup at all, we'll just
skip it altogether to ensure we have a consistent backup of everything
else that is actually important.
Uploading large files can take a very long time. If the process takes
longer than the configured timeout in Apache, it will be aborted and the
client will receive an HTTP 504 Gateway Timeout error. Increasing the
timeout will help alleviate this for files up to a certain size.
Notably, it now lets me upload Signal backups without errors.
Nextcloud thinks it needs to run the upgrade/migration tool if the
version number in its configuration file does not match the running
version. It then updates the config file with the correct version. The
next time the configuration policy is applied, however, the version will
revert back to whatever is set in the template. This will re-trigger
the upgrade notification.
To avoid this problem, we now set the version in the configuration file
dynamically. Nextcloud writes its version number in a constant in
`version.php`.
Nextcloud uses double backslashes in its fully-qualified path names.
Although single backslashes work, the application will replace them,
leading to a constant conflict between itself and the Ansible template.
The first time launching a container after pulling a new image, it can
take several minutes for the container to actually start. Podman has to
set up the overlay filesystems, which is very slow on a Raspberry Pi.
With the default start timeout, systemd may end up killing the process
before the container is completely set up. Thus, we need to increase
the timeout to ensure there is plenty of time for Podman to work.
Processes running in containers only have access to a limited set of
devices, based on their SELinux type label. The USB serial devices
exposed by the Zwave and Zigbee adapters are not labelled correctly by
default to allow them to be used in containers.
Using `chcon` to change the type label of the device before starting the
container seems to work, but seems a bit kludgy. It would probably be
better to use a SELinux file context rule and/or a udev rule to ensure
the label is set correctly when the device node is created.
Although Home Assistant itself will start fine if the network is not yet
available, some integrations will not. Notably, the Matrix integration
will fail to load if it cannot contact the homeserver when it is first
initialized. To avoid this problem, we can just delay starting Home
Assistant until the network is available.
Before the `burp` tool gained the `-Q` option, the only way to disable
the progress counter was through the configuration file. Since we do
not want any output from automatic backups (except of course
catastrophic failures), since it would end up being e-mailed by cron,
the progress counter had to be disabled globally. This meant that
on-demand runs on a terminal could not have a progress counter, which
was pretty disappointing.
Now that `burp` has `-Q`, this is no longer the case. Scheduled backups
can run with `-Q`, but ad-hoc runs can omit it to get a progress
counter.
Send logs to the systemd journal for easier viewing and disable logging
to a file. Also, the `samba_dc_log_level` variable can control the log
level (0-10, 0 being off, 10 being insane debugging).
Docker is effectively deprecated by Fedora/Red Hat. It is a pain in the
ass to work with anyway. Podman integrates better with systemd, and is
in general more aligned with how I prefer to deploy and manage
applications.
I am following the same pattern here that I have used for Home
Assistant, ZWaveJS2MQTT, etc. The systemd service starts the container
with `podman`, passing the necessary arguments for UID/GID mapping, etc.
Note that, by default, Vaultwarden expects to be able to bind to port
80; since the container is unprivileged, we have to configure it (or
rather, its embedded HTTP server [Rocket](https://rocket.rs)) to listen
on a different port. We also configure it to listen only on the
loopback, since it is being proxied by Apache to the outside network.
To migrate the data from the Docker volume, we just have to copy the
files and fix their ownership.
The *bitwarden_rs* project was recently renamed to *Vaultwarden*, so I
took this opportunity to update the name in most places within the
*bitwarden_rs* role.
Sometimes I need to configure a machine to be a domain member without
actually adding it to the domain. Now I can by running
`ansible-playbook` with `--skip-tags domain-join`
I honestly don't remember why the `use rfc2307` setting was only enabled
on the first DC. All DCs seem to need this setting in order to use the
UID/GID numbers from the directory, instead of using auto-generated
numbers.
If the remote address configuration for strongSwan is not valid when the
Proton VPN watchdog starts, it will now regenerate it immediately. This
can happen, for example, if the Internet has been down for a while, and
the watchdog has iterated through all of the servers in the cache.
Restarting the service will now force it to reconfigure the tunnel and
bring the VPN back up.
The `collectd-version` script uses the *collectd* UNIX socket to send
custom values to *collectd* to track the OS version. Since these values
obviously cannot change while the system is running, the values are
specified with a very long interval. This avoids having to continuously
insert the values, either with a long-running process or by repeatedly
running a script. The values only need to be inserted once when
*collectd* starts.
All values sent to *collectd* must have an associated type. The type
defines the acceptable range of values. Types are defined in a simple
text file database. *collectd* loads all of the databases specified by
`TypesDB` directives in its configuration file. When configuring a
custom types database, the default database needs to be specified
explicitly; it will not be loaded automatically if there are any
`TypesDB` directives in the configuration.
The *unixsock* plugin for *collectd* provides a socket-based interface
that other software can use to communicate with *collectd*. Notably,
this can be used to publish custom values, query existing values, and
flush caches.
The socket is created at `/run/collectd/socket`. The `/run/collectd`
directory is managed by systemd; it will be created automatically when
the service starts and cleaned up when it stops.
The *collectd-prometheus* role now has a
`collectd_prometheus_allow_outsize` variable. This variable controls
whether or not external hosts are allowed to scrape data from *collectd*.
When set to `false`, as is the default value, *collectd* will be
configured to listen on the loopback interface only, and the TCP port
will not be opened in the firewall.
Synapse supports exporting metrics in Prometheus format. It can do this
either as part of the main server, or in a separate listener. I chose
to use a separate listener so that the metrics are not exposed
publicly.
Dustin