This way we don't rely on installed plugin (to avoid the deployment cycle) and we don't need to install into the real home of the go user to avoid risking that a broken plugin breaks all future jobs of the agent
How to validate the yaml
For some reason, valid yaml is not supported - the indentation required is rather wild. But to check the syntax before commit, you can use the plugin locally:
wget https://github.com/tomzo/gocd-yaml-config-plugin/releases/download/0.9.0/yaml-config-plugin-0.9.0.jar
java -jar yaml-config-plugin-0.9.0.jar syntax sp1-stagings.gocd.yaml | grep -q '"valid":true'