Export from one mongo database into another

dbcopy.sh

#!/usr/bin/env bash

#https://gist.github.com/EyalAr/4bc6524c3c9ae6af33a9

SOURCE_HOST=127.0.0.1
SOURCE_DB=dev

TARGET_HOST=127.0.0.1
TARGET_DB=stage

COLLECTIONS="col1 col2 col3"

for c in ${COLLECTIONS[@]}
do
    echo "$SOURCE_HOST/$SOURCE_DB/$c --> $TARGET_HOST/$TARGET_DB/$c"
    mongoexport --host $SOURCE_HOST -d $SOURCE_DB -c $c | mongoimport --host $TARGET_HOST -d $TARGET_DB -c $c
done