support merging yaml files from STDIN

[rriemann]

Dear Nico,

one more idea I would like to raise.

I thought of this use case:

cat /env/default/values.yaml /env/production/values.yaml | tpl -d yaml -f template.gotmpl

At the moment, it seems only the second yaml input file is considered if both files are delimited with --- and .... Would it be possible to join them?

[bluebrown]

Hi, I think this may be out of scope, given, you can use another tool like yq to merge the file before invoking tpl. So it would follow the unix philosophy.

However, I don't have very strong feeling on this. Do you have any suggestion how to implement this or do you want make a PR?