Dagster-Meltano

A dagster plugin that allows you to run Meltano using Dagster. Forked from the original repo that was from Quantile Devlopment; with a special thanks to Jules Huisman for the maintenance of that repo.

Installation

You can install using pip install elt-dagster-meltano.

Examples

An example of automatically loading all jobs and schedules from your Meltano project.

from dagster import repository
from dagster_meltano import load_jobs_from_meltano_project

meltano_jobs = load_jobs_from_meltano_project("<path-to-meltano-root>")

@repository
def repository():
    return [meltano_jobs]

An example of running an abitrary meltano run command.

from dagster import repository, job
from dagster_meltano import meltano_resource, meltano_run_op

@job(resource_defs={"meltano": meltano_resource})
def meltano_run_job():
    tap_done = meltano_run_op("tap-1 target-1")()
    meltano_run_op("tap-2 target-2")(tap_done)

@repository()
def repository():
    return [meltano_run_job]

You can inject Meltano config with the following Dagster config.

ops:
  tap_smoke_test_target_jsonl:
    config:
      env:
        TAP_SMOKE_TEST_STREAMS: '[{"stream_name": "new-stream", "input_filename": "demo.json"}]'

An example of running an arbitrary Meltano command.

from dagster import repository, job
from dagster_meltano import meltano_resource, meltano_command_op

@job(resource_defs={"meltano": meltano_resource})
def meltano_command_job():
    meltano_command_op("install loader tap-smoke-test")()

@repository()
def repository():
    return [meltano_command_job]

Development using VSCode

1. Open this repository in Visual Studio Code.
2. Install the Remote - Containers plugin for Visual Studio Code.
3. Go to the example Meltano project root cd meltano_project
4. Install all plugins meltano install
5. Start dagit meltano invoke dagster:start
6. Visit localhost:3000 to access Dagit.