问题
I'm working on ubuntu 15.04 (it's not a VM). I installed rails, ruby and bundler. Everything seems to work fine when I launch the server, as I get this:
sudo rails s -p 8080
Warning: Running `gem pristine --all` to regenerate your installed gemspecs (and deleting then reinstalling your bundle if you use bundle --path) will improve the startup performance of Spring.
=> Booting WEBrick
=> Rails 4.2.5.2 application starting in development on http://localhost:8080
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2016-03-31 22:38:50] INFO WEBrick 1.3.1
[2016-03-31 22:38:50] INFO ruby 2.1.2 (2014-05-08) [x86_64-linux-gnu]
[2016-03-31 22:38:50] INFO WEBrick::HTTPServer#start: pid=10415 port=8080
When I try to access to my localhost in my web browser I get "connection failed". So I tried to ping my localhost and I got:
$ ping localhost:8080
ping: unknown host localhost:8080
I also tried with telnet:
$ telnet localhost 8080
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused
And when looking at the hostname mapping, I get this :
$ cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 alex-VPCFXXXXX
After seeing that, everything seems to be normal... So I really don't get why it's not working and why I can't ping/telnet my localhost on this port (I tried with 3000 or 3001 just to be sure...)
Hope you can help me on this one :)
来源：https://stackoverflow.com/questions/36343740/rails-server-is-running-but-cannot-connect-ping-telnet-to-localhost