yq parser

file name foobarr.yml contents:

webserver:
  hosts:
    foo:
      ipaddr: 192.168.1.1
      desc: "foo is cool"
    bar:
      ipaddr: 10.0.0.1
      desc: "bar is cooler"

$ yq '.webserver.hosts[] | select(.ipaddr == "192.168.1.1")'  foobar.yml

{
 "ipaddr": "192.168.1.1"
}yq '.webserver.hosts[] | select(.ipaddr == "192.168.1.1")'  foobar.yml

pass an arg

$ yq --arg IPADDR "$ipaddr" '.webserver.hosts[] | select(.ipaddr == "192.168.1.1")' foobar.yml

show only keys

 $ yq '.webserver.hosts | keys | .[]' foobar.yml
"bar"
"foo"

csv of key + ipaddr (without quotes), use the -r (--raw-output) option:

$ yq -r '.webserver.hosts | to_entries[] | "\(.key),\(.value.ipaddr)"' file.yml
foo,192.168.1.1
bar,10.0.0.1