We've decided to focus primarily on the CLI for the moment, which you can see showcased through the example code on the homepage: https://meltano.com, but we're working on a UI as well, as evidenced by today's release blog post: https://meltano.com/blog/2020/08/17/now-available-meltano-v1...
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Meltano uses open source Singer taps and targets (https://singer.io) as its extractors and loaders, so to put together something similar to DropBase (which looks amazing, by the way), you could use:
- tap-spreadsheets-anywhere (https://github.com/ets/tap-spreadsheets-anywhere, https://gitlab.com/meltano/meltano/-/merge_requests/1813), which supports CSV and XLS over S3, HTTP(S), (S)FTP (etc),
along with:
- target-postgres (https://github.com/meltano/target-postgres, https://meltano.com/plugins/loaders/postgres.html),
- target-jsonl (https://github.com/andyh1203/target-jsonl, https://meltano.com/plugins/loaders/jsonl.html), or
- any of the others you find on https://meltano.com/plugins/extractors/, https://meltano.com/plugins/loaders/, or https://www.singer.io/.
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For transformation, Meltano currently supports only dbt (https://www.getdbt.com/), which means that unlike DropBase, it's built for ELT rather than ETL, since transformation takes place inside the loading database, rather than in between the E and L steps.
I'm very interested in exploring the ETL direction more, though, because as DropBase clearly shows, there are still a lot of companies and people who may not be experts on SQL, but would benefit tremendously from sturdy ETL with an accessible interface and flexible integration points.
As I just wrote on our Slack workspace (there's a link on https://meltano.com):
> I’d love to see Meltano UI develop into that direction for simple transformations over Singer tap stream/entity schema and record JSON, so that we can do ETL as well as dbt-backed ELT.
> We’d probably start with a way of specifying transformations in `meltano.yml`, similar in spirit to the `select`, `schema`, and `metadata` extra’s (https://meltano.com/docs/command-line-interface.html#extract...), and/or by pointing at a Python file that can process each Singer message. Building a DropBase-style UI over that would be on the horizon too, once we’ve brought the Entity Selection interface back (https://gitlab.com/meltano/meltano/-/issues/2002) and add interfaces for metadata rules and schema overrides.
I'll create some more issues around this potential direction tomorrow :-)
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If you or anyone else interested in open source, self-hosted ETL/ELT end up giving it a try, I'd love to hear what you think, so that we can figure out how to build it into this direction together!