{#
# vi:syntax=jinja
#}

{#- Generates one known_hosts entry per given key #}
{%- macro known_host_entry(host, host_names, keys) %}

{#-   Get IPv4 and IPv6 addresses from the DNS #}
{%-   set ip4 = salt['dig.A'](host) -%}
{%-   set ip6 = salt['dig.AAAA'](host) -%}

{#-   The host names to use are to be found within the dict 'host_names'. #}
{#-   If there are none, the host is used directly. #}
{%-   set names = [host_names.get(host, host)] -%}

{#-   Append IP addresses and aliases (if they are not already present) #}
{%-   for ip in (ip4 + ip6)|sort -%}
{%-     do names.append(ip) -%}
{%-     for alias in aliases_ips.get(ip, []) -%}
{%-       if alias not in names -%}
{%-         do names.append(alias) -%}
{%-       endif -%}
{%-     endfor -%}
{%-   endfor -%}

{#-   Write one line per key; join the names together #}
{%-   for line in keys.split('\n') -%}
{%-     if line -%}
{{        ','.join(names) }} {{ line }}
{%      endif -%}
{%-   endfor -%}
{%- endmacro -%}

{#- Pre-fetch pillar data #}
{%- set target = salt['pillar.get']('openssh:known_hosts:target', '*') -%}
{%- set expr_form = salt['pillar.get']('openssh:known_hosts:expr_form', 'glob') -%}
{%- set keys_function = salt['pillar.get']('openssh:known_hosts:mine_keys_function', 'public_ssh_host_keys') -%}
{%- set hostname_function = salt['pillar.get']('openssh:known_hosts:mine_hostname_function', 'public_ssh_hostname') -%}

{#- Lookup IP of all aliases so that when we have a matching IP, we inject the alias name
    in the SSH known_hosts entry -#}
{%- set aliases = salt['pillar.get']('openssh:known_hosts:aliases', []) -%}
{%- set aliases_ips = {} -%}
{%- for alias in aliases -%}
  {%- for ip in salt['dig.A'](alias) + salt['dig.AAAA'](alias) -%}
    {%- do aliases_ips.setdefault(ip, []).append(alias) -%}
  {%- endfor -%}
{%- endfor -%}

{#- Loop over targetted minions -#}
{%- set host_keys = salt['mine.get'](target, keys_function, expr_form=expr_form) -%}
{%- set host_names = salt['mine.get'](target, hostname_function, expr_form=expr_form) -%}
{%- for host, keys in host_keys|dictsort -%}
{{ known_host_entry(host, host_names, keys) }}
{%- endfor -%}