ansible: playbook for postgres and gitea

ansible/README.md

@@ -35,4 +35,12 @@ which brew && brew install coreutils # if on macos
 ```sh
 eval "$(ssh-agent -s)"
 ssh-add ~/.ssh/id_rsa
+```
+
+## dev
+
+### test an expression
+
+```sh
+ansible -i ,localhost -c local localhost -m raw -a "echo hello world {{ inventory_hostname }} : {{ hostvars | to_nice_json | regex_replace(\"['\n]\",' ') }}"
 ```