[DOC] Add documentation about how to export/import OpenSearch Dashboards saved objects

[joshuarrrr]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request and all versions that are affected.

Example user question:

Hey folks! Is there a way to export an existing dashboard from one opensearch instance to another? The index being visualized is identical on both instances

Example response:

Yeah, there are a couple ways. Through the UI, go to /app/management/opensearch-dashboards/objects. Then you can select which saved objects you want to export. For a dashboard, you’ll want all the associated visualizations as well, so you’ll want to make sure “Include related objects” remains checked. Then you can import from the same UI on the other instance.

Ideally the documentation should cover no just exporting/importing from the UI, as described above, but also via the Saved Object API.

User provided usage example: opensearch-project/OpenSearch-Dashboards#987 (comment)

Additional examples and background info about the Saved Object system index: opensearch-project/OpenSearch-Dashboards#1647

Many more user-provided API examples: opensearch-project/OpenSearch-Dashboards#1723

We should also provide a section with caveats and limitations, such as the file size limit: opensearch-project/OpenSearch-Dashboards#1166

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.

On the OpenSearch Dashboards side, we need to do some work to ensure that the UI and API make cross-compatible file formats: opensearch-project/OpenSearch-Dashboards#1526

[joshuarrrr]

Another related forum question: https://forum.opensearch.org/t/how-to-create-index-pattern-through-dashboards-api/13928/2

[vagimeli]

@kolchfa-aws See https://github.com/opensearch-project/documentation-website/pull/4876/files, as the UI has changed and Saved Objects documentation should be under the new structure.

[Alwinius]

I found out that the parameters from Kibana seem to work when using the Saved Objects API: https://www.elastic.co/guide/en/kibana/current/saved-objects-api-import.html This could and should also be part of the documentation