Assisting Mapping configuration from GUI including reindexing

[JulGor]

Describe the feature:

Assisting Mapping configuration for new (and old) indices from a visual interface (e.g.: the "Index Management" section), so Kibana users can select the correct type of each field for the index.

Once all the fields types have been changed, the UI should offer the possibility to the user of creating a template with the new mapping and reindex the baseline index (the one used to set up the new mapping) or a list of indices.

It should be great if the final reindex is double (or at least it could be chosen), so the name of the final index could be the same of the initial one by performing the following operations:

1. reindex from "index_1" to "tmp_index_1" with the new mapping
2. remove "index_1"
3. reindex from "tmp_index_1" to "index_1"
4. remove "tmp_index_1"

Describe a specific use case for the feature:

Mapping is painful starting from scratch, so it is common to index a sample of documents in a temporal index and use the mapping set by Elasticsearch from a starting point.

So the feature described above would be great to fine tune the mapping of the indices from a sample of documents.

Even, it would be better if the user wouldn't have to index the sample, so there would be a new section in the UI were a file could be uploaded with a sample of documents and Elasticsearch would suggest the mapping, allowing the user to modify it.

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

[cjcenizal]

Thanks @JulGor! Do I understand correctly that your primary use cases are:

• Creation of a new index with the ability to prepopulate the mappings based on a sample document, with the ability to tweak those mappings
• Editing the mappings of an existing index/indices (with a transparent reindex)
• Creation of an index template based on an index's settings, mappings, and aliases (with the ability to tweak them)

Note to maintainers. This looks related to a few other open issues:

• Create index ([Index Management] Create index #57059)
• Edit index ([Index Management] Edit index #57061)
• Reindex wizard (Reindex Wizard #46755)
• Morph mappings feature (Reindex wizard "morph mappings" feature #46957)

[cjcenizal]

I've created elastic/elasticsearch#54599 to track the request for an API endpoint that can provide dynamic mappings output without requiring the creation of a temporary index.

[elasticmachine]

Pinging @elastic/kibana-management (Team:Kibana Management)