basic-system: add management of /etc/hosts

basic-system/defaults/main.yml

 ---
 
 dns_hostname_fqdn: False
+hosts_alternates: []
+hosts_additionals: []

basic-system/handlers/main.yml

@@ -9,3 +9,7 @@
 
 - name: update initramfs
   command: update-initramfs -u
+
+- name: gather network facts once again
+  setup: gather_subset=network
+

basic-system/tasks/network.yml

@@ -17,6 +17,8 @@
 - name: ensure the hostname is not a fqdn
   hostname: name="{{ inventory_hostname }}"
   when: not dns_hostname_fqdn
+  notify:
+    - gather network facts once again
   tags:
     - dns
     - network
@@ -25,11 +27,25 @@
 - name: ensure the hostname is a fqdn
   hostname: name="{{ ansible_fqdn }}"
   when: dns_hostname_fqdn
+  notify:
+    - gather network facts once again
   tags:
     - dns
     - network
     - config
 
+- meta: flush_handlers
+
+- name: ensure correct hosts file
+  template:
+    src: hosts.j2
+    dest: /etc/hosts
+  notify:
+    - gather network facts once again
+  tags:
+    - dns
+    - network
+
 - name: ensure deactivation of tcp_timestamps
   sysctl: name=net.ipv4.tcp_timestamps value=0 state=present sysctl_set=yes
   tags: 

basic-system/templates/hosts.j2

+127.0.0.1	localhost
+::1     localhost ip6-localhost ip6-loopback
+fe00::0 ip6-localnet
+ff00::0 ip6-mcastprefix
+ff02::1 ip6-allnodes
+ff02::2 ip6-allrouters
+ff02::3 ip6-allhosts
+
+{%- for host in hosts_alternates %}
+{{ host }}	{{ ansible_host }} {{ inventory_hostname }}
+{% else %}
+{{ ansible_default_ipv4.address }}	{{ ansible_host }} {{ inventory_hostname }}
+{%- if address in ansible_default_ipv6 %}
+{{ ansible_default_ipv6.address }}	{{ ansible_host }} {{ inventory_hostname }}
+{% endif -%}
+{% endfor -%}
+
+{%- for host in hosts_additionals %}
+{{ host.address }}	{{ host.names|join(' ') }}
+{% endfor -%}