The Amundsen plugin imports the contents of an Amundsen metadata graph over Bolt, reading Neo4j directly.

Amundsen is a catalog, so every entry in it describes something that lives somewhere else. Each table is projected onto the Marmot provider and MRN its own technology's plugin uses, so an Amundsen import and a later native run land on one asset instead of two. amundsen/projection.go holds that mapping; it agrees with the OpenMetadata plugin's projection for the technologies they share.

What it reads

Tables and views, their columns, owners, tags, badges and programmatic descriptions; dashboards and their charts; read counts as statistics; table to table lineage from HAS_UPSTREAM, and dashboard to table lineage from DASHBOARD_WITH_TABLE.

No database, cluster or schema assets are created. Those belong to the technology's own plugin.

Naming

The Amundsen hierarchy is Database -> Cluster -> Schema -> Table, where Database holds the technology name. The cluster enters an asset's name only where the technology's Marmot name has room for it, such as the leading part of a Snowflake database.schema.table. Everywhere else it is an environment label and is recorded in metadata. A table keeps its own name and its MRN carries the path, for example mrn://asset/table/postgresql/prod.public.orders, mrn://asset/table/mysql/shop.orders and mrn://asset/table/bigquery/acme.sales.orders.

Amundsen holds no address for the systems it describes, so its MRNs have no zone. If you run two systems of one technology and their own plugins set zone, Amundsen's copies of those assets stay separate from them.

Tests

Unit tests run without Neo4j. The end to end tests need a graph:

docker run -d --name marmot-test-amundsen -p 17687:7687 \
  -e NEO4J_AUTH=neo4j/marmotpass neo4j:5-community
docker cp testdata/seed.cypher marmot-test-amundsen:/tmp/seed.cypher
docker exec marmot-test-amundsen cypher-shell -u neo4j -p marmotpass -f /tmp/seed.cypher

MARMOT_TEST_AMUNDSEN_URI=bolt://localhost:17687 \
MARMOT_TEST_AMUNDSEN_USER=neo4j \
MARMOT_TEST_AMUNDSEN_PASSWORD=marmotpass \
go test ./...