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--------------------------------------------------------------------【可能出现的问题及解决】
Seems like you have 10.0.2.2 in your localhosts.
You can check it in /etc/hosts.
It may look like
...
127.0.0.1 localhost
10.0.2.2 localhost
...
If you don't need 10.0.2.2 here and you don't know why you got it (your case =)) you can remove this line and try to run rails s again.
Maybe you would have to restart your network system or you can reboot.
Another way would be running rails server on particular host like
rails s -b 127.0.0.1
I don't know exact reasons of the problem but I hope it helps you somehow.
--------------------------------------------------------------------
-------------------------------------------------------------------【原问题】
I change webrick to puma in my development environment, but I can't run rails server, look my error:
➜ r4u rails s
=> Booting Puma
=> Rails 5.0.0.1 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.6.0 (ruby 2.3.1-p112), codename: Sleepy Sunday Serenity
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://localhost:3000
127.0.0.1
10.0.2.2
Exiting
/home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:267:in `initialize': Cannot assign requested address - bind(2) for "10.0.2.2" port 3000 (Errno::EADDRNOTAVAIL)
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:267:in `new'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:267:in `add_tcp_listener'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:260:in `block in add_tcp_listener'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:259:in `each'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:259:in `add_tcp_listener'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:102:in `block in parse'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:85:in `each'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/binder.rb:85:in `parse'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/runner.rb:133:in `load_and_bind'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/single.rb:85:in `run'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/puma/launcher.rb:172:in `run'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/puma-3.6.0/lib/rack/handler/puma.rb:51:in `run'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/rack-2.0.1/lib/rack/server.rb:296:in `start'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/server.rb:79:in `start'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:90:in `block in server'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:85:in `tap'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:85:in `server'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/railties-5.0.0.1/lib/rails/commands.rb:18:in `<top (required)>'
from /home/luiz/Dropbox/projetos/r4u/bin/rails:9:in `require'
from /home/luiz/Dropbox/projetos/r4u/bin/rails:9:in `<top (required)>'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/spring-1.7.2/lib/spring/client/rails.rb:28:in `load'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/spring-1.7.2/lib/spring/client/rails.rb:28:in `call'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/spring-1.7.2/lib/spring/client/command.rb:7:in `call'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/spring-1.7.2/lib/spring/client.rb:30:in `run'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/spring-1.7.2/bin/spring:49:in `<top (required)>'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/spring-1.7.2/lib/spring/binstub.rb:11:in `load'
from /home/luiz/.rvm/gems/ruby-2.3.1/gems/spring-1.7.2/lib/spring/binstub.rb:11:in `<top (required)>'
from /home/luiz/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /home/luiz/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /home/luiz/Dropbox/projetos/r4u/bin/spring:13:in `<top (required)>'
from bin/rails:3:in `load'
from bin/rails:3:in `<main>Ok, I know that problem is in my environment and that exist another proccess using this addresss. But how I can solve this? Look my netstats
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:17603 0.0.0.0:* LISTEN 2975/dropbox
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 1401/mysqld
tcp 0 0 127.0.0.1:5939 0.0.0.0:* LISTEN 1497/teamviewerd
tcp 0 0 192.168.122.1:53 0.0.0.0:* LISTEN 2079/dnsmasq
tcp 0 0 127.0.1.1:53 0.0.0.0:* LISTEN 1507/dnsmasq
tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN 4437/cupsd
tcp 0 0 127.0.0.1:5432 0.0.0.0:* LISTEN 1413/postgres
tcp 0 0 0.0.0.0:17500 0.0.0.0:* LISTEN 2975/dropbox
tcp 0 0 127.0.0.1:17600 0.0.0.0:* LISTEN 2975/dropbox
tcp6 0 0 :::80 :::* LISTEN 2049/apache2
tcp6 0 0 ::1:631 :::* LISTEN 4437/cupsd
tcp6 0 0 :::17500 :::* LISTEN 2975/dropbox
udp 0 0 0.0.0.0:631 0.0.0.0:* 1315/cups-browsed
udp 0 0 0.0.0.0:17500 0.0.0.0:* 2975/dropbox
udp 0 0 0.0.0.0:5353 0.0.0.0:* 3282/chrome
udp 0 0 0.0.0.0:5353 0.0.0.0:* 3282/chrome
udp 0 0 0.0.0.0:5353 0.0.0.0:* 1142/avahi-daemon:
udp 0 0 0.0.0.0:14381 0.0.0.0:* 1464/dhclient
udp 0 0 0.0.0.0:52083 0.0.0.0:* 1142/avahi-daemon:
udp 0 0 192.168.122.1:53 0.0.0.0:* 2079/dnsmasq
udp 0 0 127.0.1.1:53 0.0.0.0:* 1507/dnsmasq
udp 0 0 0.0.0.0:67 0.0.0.0:* 2079/dnsmasq
udp 0 0 0.0.0.0:68 0.0.0.0:* 1464/dhclient
udp6 0 0 :::5353 :::* 3282/chrome
udp6 0 0 :::5353 :::* 1142/avahi-daemon:
udp6 0 0 :::42534 :::* 1142/avahi-daemon:
udp6 0 0 :::22297 :::* 1464/dhclient
Active UNIX domain sockets (only servers)
Proto RefCnt Flags Type State I-Node PID/Program name Path
unix 2 [ ACC ] STREAM LISTENING 16311 2521/gnome-keyring- /run/user/1000/keyring-44aQ70/control
unix 2 [ ACC ] STREAM LISTENING 10981 2139/Xorg /tmp/.X11-unix/X0
unix 2 [ ACC ] STREAM LISTENING 21805 3282/chrome /tmp/.com.google.Chrome.ij7UG8/SingletonSocket
unix 2 [ ACC ] STREAM LISTENING 160803 18684/spring server /run/user/1000/spring-1000/2ce6127e98884ac8253b4dfd188b6d2e
unix 2 [ ACC ] STREAM LISTENING 17883 2702/gnome-session /tmp/.ICE-unix/2702
unix 2 [ ACC ] STREAM LISTENING 16689 2521/gnome-keyring- /run/user/1000/keyring-44aQ70/pkcs11
unix 2 [ ACC ] STREAM LISTENING 16693 2521/gnome-keyring- /run/user/1000/keyring-44aQ70/ssh
unix 2 [ ACC ] STREAM LISTENING 16694 2521/gnome-keyring- /run/user/1000/keyring-44aQ70/gpg
unix 2 [ ACC ] STREAM LISTENING 17882 2702/gnome-session @/tmp/.ICE-unix/2702
unix 2 [ ACC ] STREAM LISTENING 18531 2780/pulseaudio /run/user/1000/pulse/native
unix 2 [ ACC ] STREAM LISTENING 10980 2139/Xorg @/tmp/.X11-unix/X0
unix 2 [ ACC ] STREAM LISTENING 30610 3029/gvfsd-trash @/dbus-vfs-daemon/socket-q8PPBuMR
unix 2 [ ACC ] STREAM LISTENING 7237 1/init @/com/ubuntu/upstart
unix 2 [ ACC ] SEQPACKET LISTENING 9210 404/systemd-udevd /run/udev/control
unix 2 [ ACC ] STREAM LISTENING 10185 1014/dbus-daemon /var/run/dbus/system_bus_socket
unix 2 [ ACC ] STREAM LISTENING 14343 1103/bluetoothd /var/run/sdp
unix 2 [ ACC ] STREAM LISTENING 14415 1142/avahi-daemon: /var/run/avahi-daemon/socket
unix 2 [ ACC ] STREAM LISTENING 15262 2708/dbus-daemon @/tmp/dbus-enRuhGcuXb
unix 2 [ ACC ] STREAM LISTENING 11808 1322/acpid /var/run/acpid.socket
unix 2 [ ACC ] STREAM LISTENING 14534 1413/postgres /var/run/postgresql/.s.PGSQL.5432
unix 2 [ ACC ] STREAM LISTENING 17734 2523/init @/com/ubuntu/upstart-session/1000/2523
unix 2 [ ACC ] STREAM LISTENING 14064 1372/libvirtd /var/run/libvirt/libvirt-sock
unix 2 [ ACC ] STREAM LISTENING 14065 1372/libvirtd /var/run/libvirt/libvirt-sock-ro
unix 2 [ ACC ] STREAM LISTENING 14584 1401/mysqld /var/run/mysqld/mysqld.sock
unix 2 [ ACC ] STREAM LISTENING 24298 3818/gvfsd-http @/dbus-vfs-daemon/socket-vY0yhUY7
unix 2 [ ACC ] STREAM LISTENING 17751 2642/dbus-daemon @/tmp/dbus-QUMescAA1H
unix 2 [ ACC ] STREAM LISTENING 17335 2975/dropbox /home/luiz/.dropbox/command_socket
unix 2 [ ACC ] STREAM LISTENING 19116 2975/dropbox /home/luiz/.dropbox/iface_socket
unix 2 [ ACC ] STREAM LISTENING 17829 2666/ibus-daemon @/tmp/dbus-trIHWO34
unix 2 [ ACC ] STREAM LISTENING 27107 4437/cupsd /var/run/cups/cups.sockAnd my SS log
➜ r4u ss -tp
State Recv-Q Send-Q Local Address:Port Peer Address:Port
ESTAB 0 0 10.0.0.107:49782 187.73.143.66:http users:(("chrome",3282,226))
CLOSE-WAIT 1 0 10.0.0.107:35032 209.20.75.76:http users:(("plugin_host",4558,114))
ESTAB 0 0 10.0.0.107:38126 52.73.27.41:https users:(("dropbox",2975,119))
ESTAB 0 0 10.0.0.107:51506 64.233.190.189:https users:(("chrome",3282,95))
ESTAB 0 0 10.0.0.107:53868 198.252.206.25:https users:(("chrome",3282,283))
CLOSE-WAIT 1 0 10.0.0.107:45888 91.189.94.25:http users:(("ubuntu-geoip-pr",3738,9))
ESTAB 0 0 10.0.0.107:58574 192.30.253.124:https users:(("chrome",3282,273))
LAST-ACK 1 1 10.0.0.107:58274 52.7.106.188:https
ESTAB 0 0 10.0.0.107:53918 198.252.206.25:https users:(("chrome",3282,308))
ESTAB 0 0 10.0.0.107:38220 151.101.193.69:http users:(("chrome",3282,310))
CLOSE-WAIT 32 0 10.0.0.107:33284 45.58.74.1:https users:(("dropbox",2975,148))
ESTAB 0 0 10.0.0.107:54614 216.58.202.46:https users:(("chrome",3282,94))
ESTAB 0 0 10.0.0.107:38194 151.101.193.69:http users:(("chrome",3282,306))
ESTAB 0 0 10.0.0.107:53882 216.58.202.46:https users:(("chrome",3282,113))
ESTAB 0 0 10.0.0.107:49496 52.84.170.161:https users:(("dropbox",2975,130))
ESTAB 0 0 10.0.0.107:33866 151.101.129.69:http users:(("chrome",3282,296))
CLOSE-WAIT 32 0 10.0.0.107:52664 108.160.172.204:https users:(("dropbox",2975,34))
ESTAB 0 0 10.0.0.107:33934 151.101.129.69:http users:(("chrome",3282,231))
ESTAB 0 0 10.0.0.107:57396 173.255.112.173:https users:(("chrome",3282,206))
CLOSE-WAIT 32 0 10.0.0.107:35746 108.160.172.225:https users:(("dropbox",2975,99))
ESTAB 0 0 10.0.0.107:57878 201.67.45.154:http users:(("chrome",3282,158))
ESTAB 0 0 10.0.0.107:51750 162.125.34.129:https users:(("dropbox",2975,110))
ESTAB 0 0 10.0.0.107:38246 64.233.190.188:5228 users:(("chrome",3282,115))
ESTAB 0 0 10.0.0.107:55408 216.58.202.46:https users:(("chrome",3282,128))
ESTAB 0 0 10.0.0.107:58602 192.30.253.124:https users:(("chrome",3282,295))
ESTAB 0 0 10.0.0.107:44630 216.58.202.37:https users:(("chrome",3282,257))
CLOSE-WAIT 1 0 IMPORTANT I investigate the problem, occurs in puma-3.6.0/lib/puma/binder.rb @ line 260 Puma::Binder#add_tcp_listener. exactly in *TCPServer.new(host, port)*
def add_tcp_listener(host, port, optimize_for_latency=true, backlog=1024)
if host == "localhost"
localhost_addresses.each do |addr|
add_tcp_listener addr, port, optimize_for_latency, backlog
end
return
end
host = host[1..-2] if host and host[0..0] == '['
s = TCPServer.new(host, port)
if optimize_for_latency
s.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1)
end
s.setsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR, true)
s.listen backlog
@connected_port = s.addr[1]
@ios << s
s
end- So,
localhost_addressescontains 2 values["127.0.0.1", "10.0.2.2"] - The error occurs when "10.0.2.2" is passed as parameter. Why 2 address?
The localhost_addresses method
def localhost_addresses
addrs = TCPSocket.gethostbyname "localhost"
addrs[3..-1].uniq #- ['10.0.2.2']
end
来源：oschina
链接：https://my.oschina.net/airship/blog/3154043