[MongoDB I/O] Export doesn't write things to stdout

[surister]

In

cratedb-toolkit/cratedb_toolkit/io/mongodb/export.py

Line 105 in b7b8010

file = file or sys.stdout.buffer

we have default sys.stdout.buffer but the only usage in

cratedb-toolkit/cratedb_toolkit/io/mongodb/core.py

Line 118 in b7b8010

collection_to_json(db[args.collection], file=buffer)

we pass a BytesIO object, so in reality we never throw the documents to the stdout.

Meaning that as per explained in https://cratedb-toolkit.readthedocs.io/io/mongodb/migr8.html, we cannot migr8 export ... > data.json

If we dummy fix this, we still get the header in the file, any tool taking advantage of this should take this into consideration.

[surister]

In fact, the first info line breaks the integration with cr8 insert-json, if we eliminate it it works, for simple documents.

[amotl]

Thank you. Maybe this bug has been introduced while wrapping migr8 into ctk load table. We planned a documentation update, see:

• Documentation feedback on /docs/integrate/etl/mongodb.rst cratedb-guide#76

But also, if there is a bug in migr8 about the issue you are observing, we should fix it.

[amotl]

Hi. I think this problem has been addressed with the recently landed bugfix and improvement patch, so I am closing this.

• MongoDB: Various fixes and improvements #216

Thank you very much for your report, and please re-open if you think the problem still exists. Otherwise, please enjoy the fixed package. 🙏