The title of TFA was actually my reaction when I learned what Helm was actually doing. Initially I thought Helm would take an input file of YAML-with-template-b

The title of TFA was actually my reaction when I learned what Helm was actually doing. Initially I thought Helm would take an input file of YAML-with-template-bits, parse that YAML as an object, then use the provided template bits to fill in the parts of that object, then serialize the object back to YAML and write it out. Sounds reasonable, right? Nope, it's literal text substitution, so if you want to have a valid YAML as the output you better count your indentation on your fingers, and track where the newlines go or don't go.