Search code examples
jsonansiblenormalizationjmespath

Filter object by property and select with key in jmespath


I'm trying to filter properties of an object in jmespath based on the value of a subproperty and want to include only those properties where the subproperty is set to a specific value.

Based on this example data:

{
  "a": {
    "feature": {
      "enabled": true,
    }
  },
  "b": {
  },
  "c": {
    "feature": {
      "enabled": false
     }
  }
}

I'd like to get an object with all properties where the feature is enabled.

{
  "a": {
    "feature": {
      "enabled": true,
    }
  }
}

I figured I could use this jmespath query to filter the objects where property. enabled is set to true. Unfortunateley, it doesn't seem to work and instead returns an empty array.

*[?feature.enabled==`true`]

*.feature.enabled or *[feature.enabled] return just the boolean values without any context.

Even if *[?feature.enabled==true] would work, it would just be an array of the property values, but I need the keys (a and c) aswell. Is there any way to make this happen in jmespath?

This is all part of an ansible playbook, so there would certainly be a way to achieve selection in a different way (Jinja2 templates or custom plugin) but I wanted to try jmespath and would reason, that it should be capable of such a task.


Solution

  • Sorry, but AFAIK this is impossible in native JMESPath.
    There are custom built-in functions for this purpose in different tools like to_entries in jq.
    For jmespath.py and thus for Ansible there is hanging pull request to implement keys manipulation.

    Update: I've made a patched version of json_query filter.
    See this answer for additional info.