How to install earlier version of mongodb with homebrew?

Note: In September 2019 mongodb was removed from homebrew core, so these instructions have been updated to use mongodb-community instead, installed from the external tap.

If your current installation is still the pre-September mongodb package then you will need to use that name when you unlink, stop, relink and start, on the lines marked with #*# below.

Another option is to simply upgrade away from the deprecated package now.

I already have the latest version of mongo installed, thanks to.

brew tap mongodb/brew

brew install mongodb-community

But I want to switch to the old version sometimes. First, install it:

brew search mongo

brew install mongodb-community@3.2

Let’s stop the current mongodb, if it is running:

brew services stop mongodb/brew/mongodb-community           #*#

# or if you had started it manually

killall mongod

Now I want 3.2 on my PATH instead of the latest:

brew unlink mongodb-community                               #*#

brew link --force mongodb-community@3.2

(Apparently it needs --force because it is keg-only.)

Now I have 3.2 on my PATH, I can start the test DB:

mongod --version

brew services start mongodb/brew/mongodb-community

# or start your own mongod from the command-line

When I am finished, I can do the reverse to switch back to the latest version:

brew services stop mongodb/brew/mongodb-community

brew unlink mongodb-community@3.2

brew link mongodb-community                                 #*#

brew services start mongodb/brew/mongodb-community          #*#

And restart again.