諸般あって手元にMongoDBを入れたいなとおもったときに以前はbrewからインストールできていたのに "No available formula" になることに今更気づいたのでその解決策。
☁ brew tap mongodb/brew
Updating Homebrew...
==> Tapping mongodb/brew
Cloning into '/usr/local/Homebrew/Library/Taps/mongodb/homebrew-brew'...
remote: Enumerating objects: 51, done.
remote: Counting objects: 100% (51/51), done.
remote: Compressing objects: 100% (44/44), done.
remote: Total 250 (delta 20), reused 17 (delta 7), pack-reused 199
Receiving objects: 100% (250/250), 53.06 KiB | 362.00 KiB/s, done.
Resolving deltas: 100% (112/112), done.
Tapped 9 formulae (36 files, 111.4KB).☁ brew install mongodb-community
Updating Homebrew...
==> Installing mongodb-community from mongodb/brew
==> Downloading https://fastdl.mongodb.org/osx/mongodb-macos-x86_64-4.2.7.tgz
######################################################################## 100.0%
==> Caveats
To have launchd start mongodb/brew/mongodb-community now and restart at login:
brew services start mongodb/brew/mongodb-community
Or, if you don't want/need a background service you can just run:
mongod --config /usr/local/etc/mongod.conf