Some Linux packages (shakes fist angrily at Java) look to see if `/proc` is mounted as a part of the installation by running
`mountpoint /proc`
While the Linux jail can see the contents of its `/proc` directory, the linprocfs driver will not generate the correct contents for `/proc/mounts` or `/proc/self/mountinfo` as `kern_getfsstat()` will, by default, filter all mount points other than the jail's chroot directory.
Fix is to set `enforce_statfs` to allow mount points below the jail's chroot directory to be visible.
PF allows us to log rdr rules. The syntax to enable this is found in
pf.conf under the syntax grammar section for rdr-rule.
This commit extends Bastille's command line interface to allow users
to choose to log their rdr rules using the pf.conf syntax -
``````````````````````````````````````````````````````
tcp|udp host_port jail_port [log ['(' logopts ')'] ]
``````````````````````````````````````````````````````
Here, the syntax after jail_port is optional. This is sufficient to
provide backwards compatibility. The keyword 'log' enables logging with
the default options. The user can also provide custom options -
logopts - whose the syntax and allowed keywords are defined in pf.conf.
It's left to the user to supply correct logopts as the code does not
verify those values or their syntax.
There's quite a bit more we could do here, but this hits my basic usage
with vnets. Future work here would be things like ipv6 support or trying
to infer what a custom `interfaces` setting means.
I think these are the same concept, but with slightly different execution.
The main idea is to have a central base system that is shared (readonly) among
multiple jails. When this base system is updated, all the jails that reference
it immediately see the new system files.
This is implemented in iocage as a set of individual zfs mounts, one per
system directory. In Bastille, each system directory is symlinked into a
subdirectory of a single zfs mount.
My test plan here was to import an exported iocage basejail and verify that
its Bastille version has the right fstab and symlink changes:
```
Validating file: ssl_2021-11-19.zip...
File validation successful!
Importing 'ssl' from foreign compressed .zip archive.
Archive: ssl_2021-11-19.zip
extracting: ssl_2021-11-19
extracting: ssl_2021-11-19_root
Receiving ZFS data stream...
Generating jail.conf...
Updating symlinks...
ln: usr/src: Directory not empty
Warning: directory usr/src on imported jail was not empty and will not be updated by Bastille
Container 'ssl' imported successfully.
```
