Mongo command from unix shell with different database - bash

Question

I can connect to a mongo server using this command:
mongo host:port/admin --username=user --password=pass
and I get a mongo shell where I can execute any type of mongo commands after
I switch to the dev db (use dev).
I would like to execute a mongo command from the unix shell / command line
on the dev database, but I have access only to admin.
How can I do that? How can I specify the db I would like to use?

Answer 1

If you wish to execute just a single command, you could do it with:
mongo server:22021/my_dbname --eval "printjson(db.serverStatus())"
If you wish to execute multiple commands say residing in a file called command.js, you could do something like:
mongo server:22021/my_dbname --quiet commands.js
If you want pure shell script (SQL) style, then you could do something like:
function testMongoScript {
mongo server:22021/my_dbname <<EOF
use mydb
db.leads.findOne()
db.leads.find().count()
EOF
}
For further details, you could refer here as well.

Answer 2

You can use output redirection to run whatever command you need:
mongo localhost:27017 <<< $'rs.slaveOk()\nshow dbs'
or
echo $'rs.slaveOk()\nshow dbs' | mongo localhost:27017
just remember the \n between commands.

Answer 3

Use --authenticationDatabase to authenticate to the database where your user exists even though you are connecting to a different database:
mongo localhost:27017/dev -u user -p **** --authenticationDatabase admin
Naturally, you won't be able to do anything in the dev database your user doesn't have permissions to do.