Wordpress Update
Unfortunately - the default ubuntu install is a bit too broken to allow for an automated update.
The manual update process for simple releases is as follows:
0) Read the rel notes https://codex.wordpress.org/Version_4.9.8 (substitute the right version number)
1) Fetch a recent copy from https://wordpress.org/download/releases/
2) Then checked, unpacked and renamed it:
curl -O https://wordpress.org/wordpress-4.9.8.tar.gz openssl sha1 wordpress-4.9.8.tar.gz tar zxf wordpress-4.9.8.tar.gz sudo mv wordpress /usr/share/wordpress-4.9.8
3) Get some sanity
cd /usr/share
sudo chgrp -R www-data wordpress-4.9.8 sudo chmod -R o-rwx wordpress-4.9.8
4) Take risk (after scanning the release notes) and copy the old config across
sudo cp wordpress-4.9.7/wp-config.php wordpress-4.9.8
5) Test cursory and declared victory
Dw.