copy_to not working as expected with the mapper plugin

[sikron]

Elasticsearch version:
2.3.2

JVM version:
1.7.0_101 x64

OS version:
Ubuntu 14.04

Description of the problem including expected versus actual behavior:
Hi,
i am using Elasticsearch 2.3.2 with the Mapper Attachments Plugin. I try to copy the extracted content to another field, as described here
This is not working for me, though.

I also found a closed bug here #14946. But the discussion does it not make clear, whether the bug has been resolved or not.

Therefore i would be happy, if you could give me a definitive answer, whether this is possible or not.

Steps to reproduce:
curl -XPOST 'http://localhost:9200/test' -d '{
"entry": {
"properties": {
"file": {
"type": "attachment",
"fields": {
"content": {
"type": "string",
"copy_to": "fulltext_en"
}
}
},
"fulltext_en": {
"type": "string",
"analyzer": "english"
}
}
}
}'

curl -XPOST 'http://localhost:9200/test/entry' -d '{
"file": "TG9yZW0gaXBzdW0gZG9sb3Igc2l0IGFtZXQ="
}'
// the base64 is "Lorem ipsum dolor sit amet"

curl -XPOST 'http://localhost:9200/test/_search' -d '
{
"query": {
"match": {
"fulltext_en": "ipsum"
}
}
}'

the result of the search is then empty, which is wrong, as "ipsum" is contained in the base64.

[clintongormley]

Hi @sikron

Yes, copy_to is no longer allowed on multi-fields as of #10802. In fact, for field types other than attachment, we throw an exception if you try to add copy_to to a multi-field (#15213). This isn't something we can fix in mappings, without introducing a lot of complexity which is likely to carry bugs with it.

The mapper-attachment plugin is deprecated in favour of the ingest-attachment plugin, so this is not something that we're going to fix, but I will remove the docs claiming that we support copy_to.

[sikron]

hi, thx for clarification!