How to search in filtered list of nested objects only - elasticsearch

Question

this seems to be a complex one - not sure if it's possible to manage without scripting + I would like to be able to boost name or value fields.
Let's imagine the following documents:
{
"name":"Red Big Blue document",
"nested_key_value_properties":[
{
"key":"description 1",
"value":"red"
},
{
"key":"description 2",
"value":"big"
},
{
"key":"description 3",
"value":"blue"
}
]
}
{
"name":"Black Small Red document",
"nested_key_value_properties":[
{
"key":"description 1",
"value":"red"
},
{
"key":"description 2",
"value":"small"
},
{
"key":"description 3",
"value":"black"
}
]
}
{
"name":"Yellow Big Red document",
"nested_key_value_properties":[
{
"key":"description 1",
"value":"yellow"
},
{
"key":"description 2",
"value":"big"
},
{
"key":"description 3",
"value":"red"
}
]
}
I wish to get the documents that have the key description 1 of the value of red only (first and second document) - the last document should not be in results.

Answer 1

TLDR;
Elastic flatten objects. Such that
{
"group" : "fans",
"user" : [
{
"first" : "John",
"last" : "Smith"
},
{
"first" : "Alice",
"last" : "White"
}
]
}
Turn into:
{
"group" : "fans",
"user.first" : [ "alice", "john" ],
"user.last" : [ "smith", "white" ]
}
To avoid that you need to set the mapping manually by telling that nested_key_value_properties is going to be a nested field.
And then perform a nested query.
See below for how to do so.
To reproduce
PUT /71217348/
{
"settings": {},
"mappings": {
"properties": {
"name": {
"type": "text"
},
"nested_key_value_properties": {
"type": "nested",
"properties": {
"key": {
"type": "keyword"
},
"value": {
"type": "keyword"
}
}
}
}
}
}
POST /_bulk
{"index":{"_index":"71217348"}}
{"name":"Red Big Blue document","nested_key_value_properties":[{"key":"description 1","value":"red"},{"key":"description 2","value":"big"},{"key":"description 3","value":"blue"}]}
{"index":{"_index":"71217348"}}
{"name":"Black Small Red document","nested_key_value_properties":[{"key":"description 1","value":"red"},{"key":"description 2","value":"small"},{"key":"description 3","value":"black"}]}
{"index":{"_index":"71217348"}}
{"name":"Yellow Big Red document","nested_key_value_properties":[{"key":"description 1","value":"yellow"},{"key":"description 2","value":"big"},{"key":"description 3","value":"red"}]}
GET /71217348/_search
{
"query": {
"nested": {
"path": "nested_key_value_properties",
"query": {
"bool": {
"must": [
{
"match": {
"nested_key_value_properties.key": "description 1"
}
},
{
"match": {
"nested_key_value_properties.value": "red"
}
}
]
}
}
}
}
}