Does anyone know what json-query filter can be used to select Tigger's food in the sample JSON below? The JSON is a simplified stand-in for a massive and relatively complicated AWS blob.
Some background: I was rather pleased to discover that Ansible has a json-query filter. Given that I was trying to select an element from an AWS JSON blob this looked as if it was just what I needed. However I quickly ran into trouble because the AWS objects have tags and I needed to select items by tag.
I tried selector paths equivalent to Foods[Tags[(Key='For') & (Value='Tigger')]]
and similar but didn't manage to get it to work. Using a standalone json-query library such as https://www.npmjs.com/package/json-query I can use the parent
attribute but that does not appear to be in Ansible, quite apart from being a deviation from the core idea of json-query.
It might be better to sidestep the problem and use a jsonpath selector. jsonpath is similar to json-query and is a translation from xpath.
{ "Foods" :
[ { "Id": 456
, "Tags":
[ {"Key":"For", "Value":"Heffalump"}
, {"Key":"Purpose", "Value":"Food"}
]
}
, { "Id": 678
, "Tags":
[ {"Key":"For", "Value":"Tigger"}
, {"Key":"Purpose", "Value":"Food"}
]
}
, { "Id": 911
, "Tags":
[ {"Key":"For", "Value":"Roo"}
, {"Key":"Purpose", "Value":"Food"}
]
}
]
}
References
- json_query in ansible: http://docs.ansible.com/ansible/playbooks_filters.html#json-query-filter
- json-query standalone node: https://www.npmjs.com/package/json-query
- jmespath, the library ansible uses: http://jmespath.org/
- json-query standalone python: https://pypi.python.org/pypi/jsonquery/ (red herring)
Do you need list of ids? If so, try:
First construct simple objects with necessary fields and then pipe it to a filter.