DB import/export

[richard-epsilla]

Describe the feature
Step 1: docker support

• Add a new API to export db as a tarball and download to local:

GET /api/<DBName>/export

• Add a new API to import db from a tarball, post as payload:

POST \
     -H "Content-Type: multipart/form-data" \
     -F "file=@/path/to/your/tarball" \
     -F "json={\"name\": \"the DB name\", \"path\": \"path/on/docker/disk\"};type=application/json" \
     /api/import

Step 2. cloud support

• TBD

Motivation and use case

• To support easy db migration between docker images

Additional context

• to be filled