Make the streaming API also handle websockets (because trying to get the browser EventSource interface to

work flawlessly was a nightmare). WARNING: This commit makes the web UI connect to the streaming API instead
of ActionCable like before. This means that if you are upgrading, you should set that up beforehand.

docs/Running-Mastodon/Production-guide.md

@@ -49,6 +49,22 @@ server {
     tcp_nodelay on;
   }
 
+  location /api/v1/streaming {
+    proxy_set_header Host $host;
+    proxy_set_header X-Real-IP $remote_addr;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    proxy_set_header X-Forwarded-Proto https;
+
+    proxy_pass http://localhost:4000;
+    proxy_buffering off;
+    proxy_redirect off;
+    proxy_http_version 1.1;
+    proxy_set_header Upgrade $http_upgrade;
+    proxy_set_header Connection $connection_upgrade;
+
+    tcp_nodelay on;
+  }
+
   error_page 500 501 502 503 504 /500.html;
 }
 ```
@@ -162,6 +178,27 @@ Restart=always
 WantedBy=multi-user.target
 ```
 
+Example systemd configuration file for the streaming API, to be placed in `/etc/systemd/system/mastodon-streaming.service`:
+
+```systemd
+[Unit]
+Description=mastodon-streaming
+After=network.target
+
+[Service]
+Type=simple
+User=mastodon
+WorkingDirectory=/home/mastodon/live
+Environment="NODE_ENV=production"
+Environment="PORT=4000"
+ExecStart=/usr/bin/npm run start
+TimeoutSec=15
+Restart=always
+
+[Install]
+WantedBy=multi-user.target
+```
+
 This allows you to `sudo systemctl enable mastodon-*.service` and `sudo systemctl start mastodon-*.service` to get things going.
 
 ## Cronjobs