ElasticBeanstalk 中的 ActionCable 失败并出现无法追踪的错误

Question

ElasticBeanstalk 是一种应用程序负载均衡器配置。它是一个 Ruby on Rails，具有 Passenger、Puma 和 NGINX（默认 Ruby AWS 堆栈）。

我正在强制使用 ssl，并且我的一切都运行良好，除了 websockets，这似乎是（阻塞|丢弃|损坏）。

控制台显示第一个错误：(URL is my domain)

WebSocket connection to 'wss://<URL>/cable' failed: WebSocket is closed before the connection is established.

此请求失败，前端出现(OPCODE -1)。

通过检查服务器日志，我有 access.log 显示：

/cable"499 这不是一个描述性很强的错误。

轨道production.log 显示：

Started GET "/cable/" [WebSocket] for 152.170.14.251 at 2018-05-28 21:01:27 +0000

Successfully upgraded to WebSocket (REQUEST_METHOD: GET, HTTP_CONNECTION: upgrade, HTTP_UPGRADE: websocket)

Registered connection (Z2lkOi8vYXNlc29yLWFwcC9JZGVudGl0eS81:Z2lkOi8vYXNlc29yLWFwcC9Vc2VyLzI)

WebSocket error occurred: wrong number of arguments (given 2, expected 1)

有时我会看到另一个错误：

NoMethodError: undefined method `+' for nil:NilClass

File "/opt/rubies/ruby-2.5.1/lib/ruby/gems/2.5.0/gems/websocket-driver-0.7.0/lib/websocket/driver/hybi.rb" line 11 in generate_accept
File "/opt/rubies/ruby-2.5.1/lib/ruby/gems/2.5.0/gems/websocket-driver-0.7.0/lib/websocket/driver/hybi.rb" line 76 in initialize
File "/opt/rubies/ruby-2.5.1/lib/ruby/gems/2.5.0/gems/websocket-driver-0.7.0/lib/websocket/driver.rb" line 160 in new
File "/opt/rubies/ruby-2.5.1/lib/ruby/gems/2.5.0/gems/websocket-driver-0.7.0/lib/websocket/driver.rb" line 160 in rack
File "/opt/rubies/ruby-2.5.1/lib/ruby/gems/2.5.0/gems/actioncable-5.2.0/lib/action_cable/connection/client_socket.rb" line 47 in initialize

该文件显示缺少密钥。

通过跟踪该错误，我发现了这个问题：

Rails Issue

这让我看到了这个最终文件：

File variable that seems to be missing

这最终使我找到了可能缺少的配置：

socket.env

经过大量调查，我最终找到了 gem 源代码，看起来某些字符的编码失败并创建了一个 ActionCable 无法解析的奇怪字符串：

Open Issue in Github

Answer 1

对于默认的 Ruby AWS 堆栈（您提到过），您需要编辑默认的 nginx 配置以支持 websocket。 Elastic Beanstalk/Ruby/Puma 堆栈的默认 nginx 配置 can be found here.

基本上，您需要为 websockets 添加这些 http 标头：

proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "Upgrade";

执行此操作的一种方法是在项目的根目录中添加一个.ebextensions 文件夹，并在其中放置一个配置文件，其中包含默认配置的自定义版本。例如：

# .ebextensions/001_nginx.conf

files:
   "/opt/elasticbeanstalk/support/conf/webapp_healthd.conf":
     owner: root
     group: root
     mode: "000644"
     content: |
       upstream my_app {
         server unix:///var/run/puma/my_app.sock;
       }

       log_format healthd '$msec"$uri"'
                       '$status"$request_time"$upstream_response_time"'
                       '$http_x_forwarded_for';

       server {
         listen 80;
         server_name _ localhost; # need to listen to localhost for worker tier

         if ($time_iso8601 ~ "^(\d{4})-(\d{2})-(\d{2})T(\d{2})") {
           set $year $1;
           set $month $2;
           set $day $3;
           set $hour $4;
         }

         access_log  /var/log/nginx/access.log  main;
         access_log /var/log/nginx/healthd/application.log.$year-$month-$day-$hour healthd;

         location / {
           proxy_pass http://my_app; # match the name of upstream directive which is defined above
           proxy_set_header Host $host;
           proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
           proxy_http_version 1.1;
           proxy_set_header Upgrade $http_upgrade;
           proxy_set_header Connection "Upgrade";
         }

         location /assets {
           alias /var/app/current/public/assets;
           gzip_static on;
           gzip on;
           expires max;
           add_header Cache-Control public;
         }

         location /public {
           alias /var/app/current/public;
           gzip_static on;
           gzip on;
           expires max;
           add_header Cache-Control public;
         }
       }

container_commands:
  99_restart_nginx:
    command: "service nginx restart || service nginx start"

部署此配置后，如果您为您的 EB 实例设置了 SSH，您可以通过 SSH 登录并检查您的 nginx 配置，以查看是否正在使用您修改的版本。如果您在此处或日志中没有看到更改并且这不是生产实例，您可能需要考虑从 AWS 控制台重建环境。