check for dpkg lock, update mysql checks

install.sh

@@ -30,6 +30,14 @@ if [ -d "/etc/apache2/" ] || [ -d "/etc/php/" ] || [ -d "/etc/varnish/" ]; then
   sleep 5
 fi
 
+# check for dpkg lock
+if lsof /var/lib/dpkg/lock-frontend ; then
+  echo "Could not get lock /var/lib/dpkg/lock-frontend"
+  echo "See output above for info on what is holding the lock."
+  echo "Wait for the command above to complete, then re-run this script."
+  exit 1
+fi
+
 apt-get update
 
 # create local systemd dir
@@ -56,6 +64,14 @@ if [ ! -d "/etc/mysql/" ]; then
   mysql -e "CREATE USER 'nagios'@'localhost' IDENTIFIED WITH mysql_native_password AS '';"
   mysqladmin flush-privileges
 
+elif ! systemctl is-active --quiet mysql ; then
+
+  echo "MySQL config dir exists, but MySQL/MariaDB server is not running."
+  echo "Check your server config and either make sure MySQL is running"
+  echo "or purge MySQL/MariaDB and all related packages (e.g. mysql-common)"
+  echo "from the server and then re-run this installer."
+  exit 1
+
 fi
 
 # Apache w/ PHP