CODEWITHSUNDEEP
ruby-on-railsrubylocalhostwebrick
Lou
Lou

Reputation: 705

Why does Ruby on Rails use http://0.0.0.0:3000 instead of http://localhost:3000?

When I tried to follow the official "Getting Started" Ruby on Rails tutorial, it went wrong very quickly. Basically it said :

…navigate to http://localhost:3000. You should see Rails’ default information page.

But when I follow the instructions, I get

=> Rails 2.3.4 application starting on http://0.0.0.0:3000

After trying both addresses, I know that they point to the same thing, but can someone explain to me why Ruby on Rails uses http://0.0.0.0:3000 instead of http://localhost:3000?

Is there a way to always have the WEBrick server use localhost?

Upvotes: 45

Views: 72142

Answers (7)

Joshua Pinter
Joshua Pinter

Reputation: 47471

Rails 4.1 Warning Message.

FYI, on Rails 4.1 you will get a warning message on boot that looks like this: 

=> Run `rails server -h` for more startup options
=> Notice: server is listening on all interfaces (0.0.0.0). Consider using 127.0.0.1 (--binding option)

This indicates that binding to 0.0.0.0 is not recommended and instead you should use 127.0.0.1.

In Rails 4.2+ the Rails server default binding is to localhost instead of 0.0.0.0 or even 127.0.0.1.

Upvotes: 2

Omer Aslam
Omer Aslam

Reputation: 4864

Restarted the os works for me. (On Mac v 10.12)

Upvotes: 0

ecoologic
ecoologic

Reputation: 10420

If you want localhost, one quick way is to specify the binding rails s -blocalhost (and the port with -pNNNN, more options with rails s --help).

My server started running by default on localhost for reasons to be investigated. As a result lvh.me stopped working, preventing me from specifying subdomains (eg: www.lvh.me:3000).

I "solved" this specifying the binding:

rails s -b0.0.0.0 # will work with lvh.me

Upvotes: 2

Rob R
Rob R

Reputation: 1

For those of us using Nitrous.io virtual server envrionment for development, I believe we have to bind to 0.0.0.0 as there is no localhost per se.

Upvotes: 0

John Vandivier
John Vandivier

Reputation: 2426

Just so everyone knows, my firefox browser correctly displays the locally hosted server if I access http://localhost:3000/ but it does NOT display when I attempt to access http://0.0.0.0:3000/ as recommended by Ruby. Clearly, in some sense, they are not equivalent.

I'm on Windows btw.

Upvotes: 3

Michael Krelin - hacker
Michael Krelin - hacker

Reputation: 143051

0.0.0.0 means all interfaces. Including 127.0.0.1 a.k.a. localhost.

Upvotes: 21

andri
andri

Reputation: 11292

Localhost means quite literally "your local host", usually identified by 127.0.0.1 and all traffic to that address is routed via a loopback interface. If your Web server is listening for connections on 127.0.0.1, this means that it only accepts requests coming from the same host.

0.0.0.0 means that Rails is listening on all interfaces, not just the loopback interface.

Upvotes: 63

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