mesh-interfaces: fix networking.service to finally unfuck systemd start

ordering

roles/mesh-interfaces/files/networking.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=ifupdown2 networking initialization
+Documentation=man:interfaces(5) man:ifup(8) man:ifdown(8)
+Wants=network.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+SyslogIdentifier=networking
+TimeoutStopSec=30s
+ExecStart=/usr/share/ifupdown2/sbin/start-networking start
+ExecStop=/usr/share/ifupdown2/sbin/start-networking stop
+ExecReload=/usr/share/ifupdown2/sbin/start-networking reload
+
+[Install]
+WantedBy=basic.target network.target multi-user.target
+WantedBy=network-online.target

roles/mesh-interfaces/handlers/main.yml

@@ -2,3 +2,6 @@
 
 - name: Reload interfaces
   command: /sbin/ifreload -a
+
+- name: Reload systemd
+  command: systemctl daemon-reload

roles/mesh-interfaces/tasks/main.yml

@@ -9,6 +9,12 @@
 - name: Uninstall ifupdown
   apt: name=ifupdown state=absent
 
+# this is required for nginx, dhcpd and other to start correctly
+# see https://github.com/CumulusNetworks/ifupdown2/issues/30#issuecomment-360589850
+- name: Install fixed networking.service file
+  copy: src=networking.service dest=/lib/systemd/system/networking.service
+  notify: Reload systemd
+
 - name: Configure mesh interfaces
   template: src=mesh.conf.j2 dest=/etc/network/interfaces.d/mesh.conf
   notify: Reload interfaces