| 123456789101112131415161718192021 | map $http_upgrade $connection_upgrade {    default upgrade;    ''      close;}server {    listen       80;    server_name  localhost;  # your domain here    client_max_body_size 128M;  # maximum upload size    location / {        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    $scheme;        proxy_http_version 1.1;        proxy_set_header Upgrade $http_upgrade;        proxy_set_header Connection $connection_upgrade;        proxy_pass http://127.0.0.1:9000/;    }}
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