Using mikefarah’s yq v4 I want to conditionally add an IP address to a list within a yml file if it does not exist in the list already.

Given a file like:

servers:
  web:
    - 1.1.1.1
  jobs:
    - 2.2.2.2

If 1.1.1.1 was attempted to be added it should not change, if 3.3.3.3 was added to web then it should become

servers:
  web:
    - 1.1.1.1
    - 3.3.3.3
  jobs:
    - 2.2.2.2

I tried a couple of options, hoping to find something that went along the lines of append if not exists but didn’t see that option.

I eventually settled on an update with append & unique.

yq '.servers.web = (.servers.web + ["3.3.3.3"]  | unique)' test.yml

And for removal I have:

yq '.servers.web = (.servers.web - ["3.3.3.3"])' test.yml

Which seems to work fine.

Any yq experts have some advice on a more clear way of describing the first one, or is that the most clear way of doing it?