Copy a collection between two mongodbs

migrate_collection.py

#!/usr/bin/python3
from pymongo import MongoClient
from datetime import datetime, timedelta
from pprint import pprint

mongo_parameters = {
    'source_mongo': '',
    'db' : '',
    'dest_mongo' : ''
}

# init
print('Entering Migrator..')

def query_last_created(collection_name, mongo_url, query_since_hours):
    client = MongoClient(mongo_url)
    db = client[mongo_parameters['db']]
    collection = db[collection_name]

    # Query since last X hours and get the data
    dt = datetime.now() - timedelta(hours=query_since)
    res = collection.find({'createdAt' : {"$gt": dt}})

    return res

def get_all_from_collection(collection_name,mongo_url):
    client = MongoClient(mongo_url)
    db = client[mongo_parameters['db']]
    collection = db[collection_name]

    res = collection.find()
    return res

def populateById(source_cursor, collection_name):
    client = MongoClient(mongo_parameters['dest_mongo'])
    db = client[mongo_parameters['db']]
    collection = db[collection_name]

    for document in source_cursor:
        key = {'_id':document['_id']}
        collection.update(key, document, True)

    return
 
print('Exiting Migrator')