从 Docker 容器运行 Rails 服务器时，主机无法连接到 http://localhost:3000。
Docker 运行方式:
docker run -p 3000:3000 --namerailsapp -it 59b54d3bdf48
Rails 服务器:
=> Booting Puma => Rails 6.0.3.1 application starting in development => Run `rails server --help` for more startup options Puma starting in single mode... * Version 4.3.5 (ruby 2.5.1-p57), codename: Mysterious Traveller * Min threads: 5, max threads: 5 * Environment: development * Listening on tcp://127.0.0.1:3000 Use Ctrl-C to stop
From the host machine:
$ nmap localhost
Starting Nmap 7.60 ( https://nmap.org ) at 2020-06-20 20:59 CEST
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00013s latency).
Not shown: 994 closed ports
PORT STATE SERVICE
80/tcp open http
139/tcp open netbios-ssn
445/tcp open microsoft-ds
631/tcp open ipp
3000/tcp open ppp
3306/tcp open mysql
Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds
$ curl http://localhost:3000
curl: (56) Recv failure: Connection reset by peer
最佳答案
默认情况下，rails 服务器监听 IP 127.0.0.1，该 IP 在容器外部不可用。
解决方案是强制rails服务器监听端口0.0.0.0:3000:
# rails s -b 0.0.0.0
=> Booting Puma
=> Rails 6.0.3.1 application starting in development
=> Run `rails server --help` for more startup options
Puma starting in single mode...
* Version 4.3.5 (ruby 2.5.1-p57), codename: Mysterious Traveller
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop
来自主机:
$ curl http://localhost:3000
<!DOCTYPE html>
<html>
<head>
<title>Ruby on Rails</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<style type="text/css" media="screen" charset="utf-8">
body {
font-family: Georgia, sans-serif;
line-height: 2rem;
font-size: 1.3rem;
background-color: white;
margin: 0;
padding: 0;
color: #000;
}
关于ruby-on-rails - Docker 容器未在端口 3000 上公开 Rails 应用程序，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/62490467/