Grafana + Image-Renderer 環境のNginxリバースプロキシ設定

Prometheus + Grafana + Image-Renderer を利用している環境で
Nginxを挟んで80番(443番)にアクセスさせたときのNignxの設定。

単純に3000番に通すだけでは、CORSエラーなどでうまくいかなかった。

最終的に以下の設定で動作させている。

server {
    listen 80;
    server_name _;
    
    add_header 'Access-Control-Allow-Origin' '*' always;
    add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS, PUT, DELETE' always;
    add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization,x-grafana-device-id,x-grafana-org-id,x-grafana-user,x-grafana-auth,x-dashboard-uid,x-datasource-uid,x-panel-id' always;
    add_header 'Access-Control-Expose-Headers' 'Content-Length,Content-Range' always;

    location @cors_options {
        add_header 'Access-Control-Allow-Origin' '*' always;
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS, PUT, DELETE' always;
        add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization,x-grafana-device-id,x-grafana-org-id,x-grafana-user,x-grafana-auth,x-dashboard-uid,x-datasource-uid,x-panel-id' always;
        add_header 'Access-Control-Max-Age' 1728000 always;
        add_header 'Content-Type' 'text/plain; charset=utf-8' always;
        add_header 'Content-Length' 0 always;
        return 204;
    }

    # Image Renderer の直接エンドポイント（Grafanaからの内部呼び出し用）
    # 注意: これは通常外部からアクセスされるべきではない
    location = /render {
        if ($request_method = 'OPTIONS') {
            return 204;
        }

        proxy_pass http://192.168.100.100:8081/render;
        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_connect_timeout 120s;
        proxy_send_timeout 120s;
        proxy_read_timeout 120s;

        proxy_max_temp_file_size 0;
        proxy_buffering off;

        access_log /var/log/nginx/render_access.log;
        error_log /var/log/nginx/render_error.log debug;
    }

    # その他の Grafana リクエスト
    location / {
        if ($request_method = 'OPTIONS') {
            return 204;
        }
        
        proxy_pass http://192.168.100.100:3000;
        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 "upgrade";
        
        proxy_connect_timeout 60s;
        proxy_send_timeout 60s;
        proxy_read_timeout 60s;
    }

    # 静的ファイル
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
        if ($request_method = 'OPTIONS') {
            return 204;
        }
        
        proxy_pass http://192.168.100.100:3000;
        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;
        
        expires 1d;
        add_header Cache-Control "public, immutable";
    }
}

server {
    listen 443 ssl;
    server_name _;

    ssl_certificate /etc/ssl/certs/nginx-selfsigned.crt;
    ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;

    return 301 http://192.168.100.100$request_uri;
}