Using yq to modify yml files

September 23, 2022

I am trying to add new arrays to the existing yml file

for example the test.yml looks like this

visibility:
  subscribe:
    enabled: true
    type: authenticated
  view:
    enabled: true
    type: public

and I am trying to modify it to look like this

visibility:
  subscribe:
    tags: []
    orgs: []
    enabled: true
    type: authenticated
  view:
    tags: []
    orgs: []
    enabled: true
    type: public

I have used yq to do that but there seems to be an issue it does not add any new field
Here is the bash script I made

yq '.visibility.subscribe |= {"orgs":"[]"} + .' test.yml
yq '.visibility.subscribe |= {"tags":"[]"} + .' test.yml
yq '.visibility.view |= {"orgs":"[]"} + .' test.yml
yq '.visibility.view |= {"tags":"[]"} + .' test.yml

Am I using the right logic ?

>Solution :

Presuming that you’re using the yq tool that wraps jq (which appears to be the case from your starting syntax):

yq '
  .visibility.subscribe.orgs = []
| .visibility.subscribe.tags = []
| .visibility.view.orgs = []
| .visibility.view.tags = []
' test.yml

…is a simpler way to achieve output that’s semantically identical (not necessarily syntactically identical!) to your stated/desired output. The most important change necessary was changing "[]" to [].

Note that the new document is written to stdout — test.yml is not modified in-place unless the -i argument is used.