jq: group and key by property

Question

I have a list of objects that look like this:

[
  {
    "ip": "1.1.1.1",
    "component": "name1"
  },
  {
    "ip": "1.1.1.2",
    "component": "name1"
  },
  {
    "ip": "1.1.1.3",
    "component": "name2"
  },
  {
    "ip": "1.1.1.4",
    "component": "name2"
  }
]

Now I'd like to group and key that by the component and assign a list of ips to each of the components:

{
  "name1": [
    "1.1.1.1",
    "1.1.1.2"
  ]
},{
  "name2": [
    "1.1.1.3",
    "1.1.1.4"
  ]
}

Answer 1

I figured it out myself. I first group by .component and then just create new lists of ips that are indexed by the component of the first object of each group:

jq ' group_by(.component)[] | {(.[0].component): [.[] | .ip]}'