When `services.resolved.enable` is set to true, the file /etc/resolv.conf becomes a symlink to /etc/static/resolv.conf, which is a symlink to /run/systemd/resolve/stub-resolv.conf. Without this commit, tor does not have access to this file thanks to systemd confinement. This results in the following warning when tor starts:
```
[warn] Unable to stat resolver configuration in '/etc/resolv.conf': No such file or directory
[warn] Could not read your DNS config from '/etc/resolv.conf' - please investigate your DNS configuration. This is possibly a problem. Meanwhile, falling back to local DNS at 127.0.0.1.
```
To fix this, simply allow read-only access to the file when resolved is in use.
According to https://github.com/NixOS/nixpkgs/pull/161818#discussion_r824820462, the symlink may also point to /run/systemd/resolve/resolv.conf, so allow that as well.
Use a quoted heredoc to inject installBootLoader safely into the script,
and restore the previous invocation of `system` with a single argument so
that shell commands keep working.
Without this fix, evaluating a NixOS configuration with Tomcat enabled and the
default settings results in the following evaluation error:
Failed assertions:
- users.users.tomcat.group is unset. This used to default to
nogroup, but this is unsafe. For example you can create a group
for this user with:
users.users.tomcat.group = "tomcat";
users.groups.tomcat = {};
As a novice to using this module, I found the existing description to be
quite misleading. It does not at all disable pulling from the registry,
it just loads some image archive that may or may not be related to the
container you're specifying. I had thought there was extra magic behind
this option, but it's just a `docker load`. You need foreknowledge of
the contents of the archive so that whatever it contained is actually
used to run the container.
I've reworded the description to hopefully make this behavior clearer.
This bug is so obscure and unlikely that I was honestly not able to
properly write a test for it. What happens is that we are calling
handleModifiedUnit() with $unitsToStart=\%unitsToRestart. We do this to
make sure that the unit is stopped before it's started again which is
not possible by regular means because the stop phase is already done
when calling the activation script.
recordUnit() still gets $startListFile, however which is the wrong file.
The bug would be triggered if an activation script requests a service
restart for a service that has `stopIfChanged = true` and
switch-to-configuration is killed before the restart phase was run. If
the script is run again, but the activation script is not requesting
more restarts, the unit would be started instead of restarted.
We spent a whole afternoon debugging this, because upstream has very
bad software quality and the error messages were incredibly
misleading.
So let’s document it for the sanity of other people.
Btw, I think the implementation of our module is pretty brittle,
especially the part about diffing tokens to check whether they
changed. We should rather just request a new builder registration
every time, it’s not that much overhead, and always set `replace` so
it is idempotent.
