### Docker Start Failure

When using the `preparations.md` instructions...

--- If you get an `[OK]` message when doing `sudo service docker start`, but the `docker run hello-world` command fails:

Run the docker daemon on the terminal directly in debug mode

```
dockerd -D
```

If you get this message at the end of the output, this means we need the legacy iptables...

```
DEBU[2023-05-30T11:13:13.522324640-04:00] sd notification                               error="<nil>" notified=false state="STOPPING=1"
failed to start daemon: Error initializing network controller: error obtaining controller instance: unable to add return rule in DOCKER-ISOLATION-STAGE-1 chain:  (iptables failed: iptables --wait -A DOCKER-ISOLATION-STAGE-1 -j RETURN: iptables v1.8.7 (nf_tables):  RULE_APPEND failed (No such file or directory): rule in chain DOCKER-ISOLATION-STAGE-1
 (exit status 4))
```

This can be fixed by running these commands...

```
sudo update-alternatives --set iptables /usr/sbin/iptables-legacy
sudo update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy
```

Once complete, start #3 on the `preparations.md` instructions over again.

Thank you to [coarsehorse](https://gist.github.com/coarsehorse) for identifying the resolution for this problem.