Need a better approach to sorting semantic version strings in Elasticsearch

example.sh

# Delete the example index
curl -XDELETE "http://localhost:9200/sortable-version-test?pretty=true"

# Create a new example index
curl -X POST "http://localhost:9200/sortable-version-test?pretty=true"

# Set the mapping. Assumes version.groovy resides in $ES_HOME/config/scripts
curl -XPOST "http://localhost:9200/sortable-version-test/version/_mapping?pretty=true" -d'
{
  "version": {
    "transform": {
      "lang":"groovy",
      "script":"version"
    },
    "properties": {
      "version": {
        "type": "string",
        "fields": {
           "sortable": {
              "type": "string",
              "index": "not_analyzed"
           }
        }
      }
    }
  }
}'

# Post some test docs
curl -X POST "http://localhost:9200/sortable-version-test/version/1?pretty=true" -d'
{
  "version": "10.10.1"
}'

curl -X POST "http://localhost:9200/sortable-version-test/version/2?pretty=true" -d'
{
  "version": "10.1.1"
}'

curl -X POST "http://localhost:9200/sortable-version-test/version/3?pretty=true" -d'
{
  "version": "2.11.0"
}'

curl -X POST "http://localhost:9200/sortable-version-test/version/4?pretty=true" -d'
{
  "version": "2.10.1"
}'

curl -X POST "http://localhost:9200/sortable-version-test/version/5?pretty=true" -d'
{
  "version": "2.1.1"
}'

curl -X POST "http://localhost:9200/sortable-version-test/version/6?pretty=true" -d'
{
  "version": "1.10.0"
}'

curl -X POST "http://localhost:9200/sortable-version-test/version/7?pretty=true" -d'
{
  "version": "1.0.0"
}'

# Wait for ES to be synced (aka refresh indices)
curl -X POST "http://localhost:9200/sortable-version-test/_refresh"

# Can successfully sort the version field
curl -X GET "http://localhost:9200/sortable-version-test/version/_search?sort=version.sortable&pretty=true"

# Can successfully do a comparison, assuming string is normalized in the query
curl -X GET "http://localhost:9200/sortable-version-test/version/_search?sort=version.sortable:desc&pretty=true" -d'
{
  "query": {
    "bool": {
      "must": [
        {
          "range": {
            "version.sortable": {
              "le": "       2      11       1"
            }
          }
        }
      ]
    }
  }
}'

# Would rather be able to specify the un-normalized semantic version string, like this
curl -X GET "http://localhost:9200/sortable-version-test/version/_search?sort=version.sortable:desc&pretty=true" -d'
{
  "query": {
    "bool": {
      "must": [
        {
          "range": {
            "version.sortable": {
              "le": "2.11.1"
            }
          }
        }
      ]
    }
  }
}'

version.groovy

res = '';
for (el in ctx._source['version'].tokenize('.')) {
  res = res + el.padLeft(8);
}
ctx._source['version.sortable'] = res;

Is this the approach that you ended up going with? I am wanting to be able to search by version ranges as well.