This alert counts how long its been since the number of "active" disks
in the RAID array on the BURP server has changed. The assumption is
that the number will typically be `1`, but it will be `2` when the
second disk synchronized before the swap occurs.
1. Grafana 8 changed the format of the query string parameters for the
Explore page.
2. vmalert no longer needs the http.pathPrefix argument when behind a
reverse proxy, rather it uses the request path like the other
Victoria Metrics components.
The way I am handling swapping out the BURP disk now is by using the
Linux MD RAID driver to manage a RAID 1 mirror array. The array
normally operates with one disk missing, as it is in the fireproof safe.
When it is time to swap the disks, I reattach the offline disk, let the
array resync, then disconnect and store the other disk.
This works considerably better than the previous method, as it does not
require BURP or the NFS server to be offline during the synchronization.
The rule is "if it is accessible on the Internet, its name ends in .net"
Although Vaultwarden can be accessed by either name, the one specified
in the Domain URL setting is the only one that works for WebAuthn.
Domain controllers only allow users in the *Domain Admins* AD group to
use `sudo` by default. *dustin* and *jenkins* need to be able to apply
configuration policy to these machines, but they are not members of said
group.
I changed the naming convention for domain controller machines. They
are no longer "numbered," since the plan is to rotate through them
quickly. For each release of Fedora, we'll create two new domain
controllers, replacing the existing ones. Their names are now randomly
generated and contain letters and numbers, so the Blackbox Exporter
check for DNS records needs to account for this.
Gitea package names (e.g. OCI images, etc.) can contain `/` charactres.
These are encoded as %2F in request paths. Apache needs to forward
these sequences to the Gitea server without decoding them.
Unfortunately, the `AllowEncodedSlashes` setting, which controls this
behavior, is a per-virtualhost setting that is *not* inherited from the
main server configuration, and therefore must be explicitly set inside
the `VirtualHost` block. This means Gitea needs its own virtual host
definition, and cannot rely on the default virtual host.
When I added the *systemd-networkd* configuration for the Kubernetes
network interface on the VM hosts, I only added the `.netdev`
configuration and forgot the `.network` part. Without the latter,
*systemd-networkd* creates the interface, but does not configure or
activate it, so it is not able to handle traffic for the VMs attached to
the bridge.
The *netboot/jenkins-agent* Ansible role configures three NBD exports:
* A single, shared, read-only export containing the Jenkins agent root
filesystem, as a SquashFS filesystem
* For each defined agent host, a writable data volume for Jenkins
workspaces
* For each defined agent host, a writable data volume for Docker
Agent hosts must have some kind of unique value to identify their
persistent data volumes. Raspberry Pi devices, for example, can use the
SoC serial number.
The `-external.url` and `-external.alert.source` command line arguments
and their corresponding environment variables can be used to configure
the "Source" links associated with alerts created by `vmalert`.
The firewall hardware is too slow to run the *prometheus_speedtest*
program. It always showed *way* lower speeds than were actually
available. I've moved the service to the Kubernetes cluster and it
works a lot better there.
*mtrcs0.pyrocufflink.red* is a Raspberry Pi CM4 on a Waveshare
CM4-IO-BASE-B carrier board with a NVMe SSD. It runs a custom OS built
using Buildroot, and is not a member of the *pyrocufflink.blue* AD
domain.
*mtrcs0.p.r* hosts Victoria Metrics/`vmagent`, `vmalert`, AlertManager,
and Grafana. I've created a unique group and playbook for it,
*metricspi*, to manage all these applications together.
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.
There is no specific playbook or role for Kubernetes. All OS
configuration is done at install time via kickstart scripts, and
deploying Kubernetes itself is done (manually) using `kubeadm init` and
`kubeadm join`.
Adding a second camera to the back yard, on the North side of the porch,
to try and figure out how the possums keep getting under the porch even
with the chicken wire around it!
We're trying to discover how the possums are getting into and out of the
house. Let's enable continuous video recording from the back yard
camera so we can observe them and come up with a plan to get rid of
them.
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.
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.
If Nextcloud does not have the Internet-facing reverse proxy listed in
its "trusted proxies" setting, it will mark all traffic as being from
the proxy itself. This breaks brute force detection, etc.
Dustin