Case insensitive tags in ES

elasticsearch.yml

# Add this to config/elasticsearch.yml file to register the custom analyzer:

# Register the custom 'lowercase_keyword' analyzer. It doesn't do anything else
# other than changing everything to lower case.
index.analysis.analyzer.lowercase_keyword.type: custom
index.analysis.analyzer.lowercase_keyword.tokenizer: keyword
index.analysis.analyzer.lowercase_keyword.filter: [lowercase]

gistfile1.sh

# Map the 'tags' property to two fields: one that isn't analyzed,
# and one that is analyzed with the 'lowercase_keyword' analyzer.
curl -XPUT 'http://localhost:9200/myindex/images/_mapping' -d '{
  "images": {
    "properties": {
      "tags": {
        "type": "multi_field",
        "fields": {
          "tags": {
            "index": "not_analyzed",
            "type": "string"
          },
          "lowercased": {
            "index": "analyzed",
            "analyzer": "lowercase_keyword",
            "type": "string"
          }
        }
      }
    }
  }
}'

# Issue queries against the index. The search query must be manually lowercased.
curl -XPOST 'http://localhost:9200/myindex/images/_search?pretty=true' -d '{
  "query": {
    "terms": {
      "tags.lowercased": [
        "event:battle at the boardwalk"
      ]
    }
  },
  "facets": {
    "tags": {
      "terms": {
        "field": "tags",
        "size": "500",
        "regex": "^team:.*"
      }
    }
  }
}'