roles/dch-storage-net: Set up/mount shared storage

The *dch-storage-net* role configures a machine to connect the storage
network and mount shared folders from the storage appliance.

The `wait-global-address.sh` script and corresponding
*wait-global-address@.service* systemd unit template are necessary to
ensure that the storage network is actually available before attempting
to mount the shared volumes. This is particularly important at boot,
since `dhcpcd` does not implement any kind of signaling that can be used
by *network-online.target*, so the network is considered "online" as
soon as the `dhcpcd` process has started. This typically results in
"network unreachable" errors.

roles/dch-storage-net/files/wait-global-address.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=Wait for global address on %I
+Requires=sys-subsystem-net-devices-%i.device
+After=network-pre.target
+Before=network-online.target
+
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/usr/local/libexec/wait-global-address.sh %I
+
+[Install]
+WantedBy=network-online.target

roles/dch-storage-net/files/wait-global-address.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+until ip -o address show dev "$1" | grep -q global; do
+    printf 'Waiting for global address on %s\n' "$1"
+    sleep 1;
+done

roles/dch-storage-net/handlers/main.yml

@@ -0,0 +1,2 @@
+- name: reload systemd
+  command: systemctl daemon-reload

roles/dch-storage-net/tasks/main.yml

@@ -0,0 +1,29 @@
+- name: ensure wait-global-address script is installed
+  copy:
+    src=wait-global-address.sh
+    dest=/usr/local/libexec/wait-global-address.sh
+    mode=0755
+- name: ensure wait-global-address unit is installed
+  copy:
+    src=wait-global-address.service
+    dest=/etc/systemd/system/wait-global-address@.service
+    mode=0644
+  notify: reload systemd
+
+- name: ensure wait-global-address service starts at boot
+  service:
+    name=wait-global-address@{{ storage_iface }}.service
+    enabled=yes
+- name: ensure wait-global-address service is running
+  service:
+    name=wait-global-address@{{ storage_iface }}.service
+    state=started
+
+- name: ensure storage volumes are mounted
+  mount:
+    path={{ item.mountpoint }}
+    src={{ item.host }}:{{ item.share }}
+    fstype={{ item.fstype|d('nfs') }}
+    opts={{ item.opts|d(omit) }}
+    state=mounted
+  with_items: '{{ mount_shared_volumes }}'