MongoDB Collection Migrator

Why it exists

Moving one collection between MongoDB clusters, without pulling in a full backup/restore toolchain, is a task that comes up often enough on personal projects to be worth a dedicated image: source URI, source collection, destination URI, destination collection, run.

What I learned

Versioning this like a real tool (it ships as tagged image versions, not "latest") turned out to matter the first time a schema mismatch surfaced mid-migration and rolling back to the previous image version was the fastest way to recover.

Status

Active. Reused whenever a personal project needs to move data between Mongo clusters.