Improve comments in ansible inventory

ansible/inventory.example

@@ -1,6 +1,11 @@
 [lemmy]
-# define the username and hostname that you use for ssh connection, and specify the domain
-# old default for lemmy_base_dir was /lemmy
+# to get started, copy this file to `inventory` and adjust the values below.
+# - `myuser@example.com`: replace with the destination you use to connect to your server via ssh
+# - `domain=example.com`: replace `example.com` with your lemmy domain
+# - `letsencrypt_contact_email=your@email.com` replace `your@email.com` with your email address,
+#                                              to get notifications if your ssl cert expires
+# - `lemmy_base_dir=/srv/lemmy`: the location on the server where lemmy can be installed, can be any folder
+#                                if you are upgrading from a previous version, set this to `/lemmy`
 myuser@example.com  domain=example.com  letsencrypt_contact_email=your@email.com lemmy_base_dir=/srv/lemmy
 
 [all:vars]

ansible/lemmy.yml

@@ -7,7 +7,7 @@
   pre_tasks:
     - name: check lemmy_base_dir
       fail:
-        msg: "lemmy_base_dir is unset, old default value was '/lemmy'"
+        msg: "`lemmy_base_dir` is unset. if you are upgrading from an older version, add `lemmy_base_dir=/lemmy` to your inventory file."
       when: lemmy_base_dir is not defined
 
     - name: install python for Ansible

ansible/lemmy_dev.yml

@@ -7,6 +7,11 @@
   # https://www.josharcher.uk/code/ansible-python-connection-failure-ubuntu-server-1604/
   gather_facts: False
   pre_tasks:
+    - name: check lemmy_base_dir
+      fail:
+        msg: "`lemmy_base_dir` is unset. if you are upgrading from an older version, add `lemmy_base_dir=/lemmy` to your inventory file."
+      when: lemmy_base_dir is not defined
+
     - name: install python for Ansible
       raw: test -e /usr/bin/python || (apt -y update && apt install -y python-minimal python-setuptools)
       args: