问题
I am very new to Ruby on Rails so when I tried to follow the official "Getting Started" ruby on rails tutorial, I was a bit disappointed because 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 WEBbrick server use localhost ?
回答1:
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.
回答2:
0.0.0.0 means all interfaces. Including 127.0.0.1 a.k.a. localhost.
回答3:
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
回答4:
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.
回答5:
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.
回答6:
Actually rails has different configuration options about if it listens to something specific or all interfaces.
回答7:
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.
回答8:
Restarted the os works for me. (On Mac v 10.12)
来源：https://stackoverflow.com/questions/1478747/why-does-ruby-on-rails-use-http-0-0-0-03000-instead-of-http-localhost3000