From 7c6132f7ddc89fb2a5ae5a85891ec82926c20e84 Mon Sep 17 00:00:00 2001
From: "Joshua M. Boniface" <joshua@boniface.me>
Date: Thu, 23 May 2019 22:38:45 -0400
Subject: [PATCH] Add node autoflush service and target

Add a systemd service to manage node flush/unflush, useful during
system startup and shutdown to avoid requiring administrator
intervention for this to occur. This is optional and the service is
not enabled by default, and the postinst script informs the
administrator of this.

Also adds a systemd target to collect the two service units together
and provide an easy way to flush+shutdown or startup+unflush the
entire PVC system.

Closes #28
---
 debian/pvc-daemon.install     |  4 +++-
 debian/pvc-daemon.postinst    | 17 ++++++++++++-----
 debian/pvc-daemon.prerm       |  4 +++-
 node-daemon/pvc-flush.service | 15 +++++++++++++++
 node-daemon/pvcd.service      |  3 ++-
 node-daemon/pvcd.target       |  7 +++++++
 6 files changed, 42 insertions(+), 8 deletions(-)
 create mode 100644 node-daemon/pvc-flush.service
 create mode 100644 node-daemon/pvcd.target

diff --git a/debian/pvc-daemon.install b/debian/pvc-daemon.install
index e7183947..6895f6a5 100644
--- a/debian/pvc-daemon.install
+++ b/debian/pvc-daemon.install
@@ -1,4 +1,6 @@
 node-daemon/pvcd.py usr/share/pvc
-node-daemon/pvcd.service lib/systemd/system
 node-daemon/pvcd.sample.yaml etc/pvc
 node-daemon/pvcd usr/share/pvc
+node-daemon/pvcd.target lib/systemd/system
+node-daemon/pvcd.service lib/systemd/system
+node-daemon/pvc-flush.service lib/systemd/system
diff --git a/debian/pvc-daemon.postinst b/debian/pvc-daemon.postinst
index 9ae80517..895a66e8 100644
--- a/debian/pvc-daemon.postinst
+++ b/debian/pvc-daemon.postinst
@@ -1,10 +1,17 @@
 #!/bin/sh
 
-# Enable the service
+# Enable the service and target
 systemctl enable /lib/systemd/system/pvcd.service
+systemctl enable /lib/systemd/system/pvcd.target
 
-if systemctl is-active --quiet pvcd.service; then
-    echo "The PVC node daemon has not been restarted; this is up to the administrator."
-else
-    echo "The PVC node daemon has not been started; create a config file at /etc/pvc/pvcd.conf then start it."
+# Inform administrator of the autoflush daemon if it is not enabled
+if ! systemctl is-active --quiet pvc-flush.service; then
+    echo "The PVC autoflush daemon (pvc-flush.service) is not enabled by default; enable it to perform automatic flush/unflush actions on host shutdown/startup."
+fi
+
+# Inform administrator of the service restart/startup not occurring automatically
+if systemctl is-active --quiet pvcd.service; then
+    echo "The PVC node daemon (pvcd.service) has not been restarted; this is up to the administrator."
+else
+    echo "The PVC node daemon (pvcd.service) has not been started; create a config file at /etc/pvc/pvcd.yaml then start it."
 fi
diff --git a/debian/pvc-daemon.prerm b/debian/pvc-daemon.prerm
index 09aaa5c3..a6e8c6ab 100644
--- a/debian/pvc-daemon.prerm
+++ b/debian/pvc-daemon.prerm
@@ -1,4 +1,6 @@
 #!/bin/sh
 
-# Disable the service
+# Disable the services
+systemctl disable pvc-flush.service
 systemctl disable pvcd.service
+systemctl disable pvcd.target
diff --git a/node-daemon/pvc-flush.service b/node-daemon/pvc-flush.service
new file mode 100644
index 00000000..814f7306
--- /dev/null
+++ b/node-daemon/pvc-flush.service
@@ -0,0 +1,15 @@
+# Parallel Virtual Cluster autoflush daemon
+
+[Unit]
+Description = Parallel Virtual Cluster autoflush daemon
+After = pvcd.service
+
+[Service]
+Type = oneshot
+WorkingDirectory = /usr/share/pvc
+ExecStart = /usr/bin/pvc node unflush
+ExecStop = /usr/bin/pvc node flush
+Restart = never
+
+[Install]
+WantedBy = pvcd.target
diff --git a/node-daemon/pvcd.service b/node-daemon/pvcd.service
index 74dfa8d2..fd2ec8b8 100644
--- a/node-daemon/pvcd.service
+++ b/node-daemon/pvcd.service
@@ -1,4 +1,5 @@
 # Parallel Virtual Cluster node daemon unit file
+
 [Unit]
 Description = Parallel Virtual Cluster node daemon
 After = network-online.target libvirtd.service zookeeper.service
@@ -12,4 +13,4 @@ ExecStart = /usr/share/pvc/pvcd.py
 Restart = on-failure
 
 [Install]
-WantedBy = multi-user.target
+WantedBy = pvcd.target
diff --git a/node-daemon/pvcd.target b/node-daemon/pvcd.target
new file mode 100644
index 00000000..96f8adb6
--- /dev/null
+++ b/node-daemon/pvcd.target
@@ -0,0 +1,7 @@
+# Parallel Virtual Cluster startup target
+
+[Unit]
+Description = Parallel Virtual Cluster target for managing all services collectively
+
+[Install]
+WantedBy = multi-user.target