Filter out missing ip6

See merge request !121

ai3-prober: add generic https prober for 'aux'/external probing

See merge request !120

Hopefully we should be able to match now

See merge request !119

Refactor the dns probe regex

See merge request !118

fix regex for ai3-prober

See merge request !117

Add custom dns probes

See merge request !116

Add the ai3-prober Prometheus blackbox prober service

See merge request !115

Set gather_facts: no on all playbooks except ai3-base

See merge request !114

Enforce consistency in using inventory_hostname instead of ansible_hostname,
and avoid referring to other host facts that require discovery when we
already have the data in the inventory.

We can't (at the moment) forbid Apache from wanting to create
empty log files in /var/log/apache2 on startup, so use a tmpfs
to work around the read-only container image.

Enable Bayesian filtering in Spamassassin

See merge request !113

Keep use_bayes_rules to 0 so we can initially feed the Bayes
database without having the BAYES_* rules applied.