リクエスト時の 400 不正なリクエスト、http://localhost/favicon.ico

Question

私は nginx を初めて使用しており、サイトは Digital Ocean にデプロイされたばかりです。ブラウザからこのサイトを開こうとすると、400 Bad Request.. Request Header or Cookie Too Largeエラー メッセージが返されます。開発者コンソールには、サーバーからの favicon.ico のリクエストに関係していることが示されています。

リクエストヘッダー

Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding:gzip, deflate
Accept-Language:en-US,en;q=0.9,ko-KR;q=0.8,ko;q=0.7
AlexaToolbar-ALX_NS_PH:AlexaToolbar/alx-4.0
Connection:keep-alive
Host:{my host ip}
Upgrade-Insecure-Requests:1
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36

NGINX 設定

user www-data;
worker_processes auto;
pid /run/nginx.pid;

events {
        worker_connections 768;
        # multi_accept on;
}

http {

        ##
        # Basic Settings
        ##

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;
        # server_tokens off;

        # server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ##
        # SSL Settings
        ##

ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
        ssl_prefer_server_ciphers on;
    ##
    # Logging Settings
    ##

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log debug;

    ##
    # Gzip Settings
    ##

    gzip on;
    gzip_disable "msie6";

    # gzip_vary on;
    # gzip_proxied any;
    # gzip_comp_level 6;
    # gzip_buffers 16 8k;
   # gzip_http_version 1.1;
        # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
    ##
    # Virtual Host Configs
    ##

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
}

/etc/nginx/conf.d/ にはファイルやサブフォルダが含まれていません

/etc/nginx/sites-enabled/デフォルト

server {
        listen 80 default_server;
        listen [::]:80 default_server;
      root /var/www/html;

        # Add index.php to the list if you are using PHP
        index index.html index.htm index.nginx-debian.html;

        server_name _;

        location / {
                # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
                try_files $uri $uri/ =404;
        }

/etc/nginx/sites-enabled/myapp

upstream myapp {
  server 159.89.123.456:80;
}

map $http_upgrade $connection_upgrade {
  default upgrade;
  '' close;
}

server {
  listen 80;
  server_name 159.89.123.456;

  location / {
      try_files $uri @proxy;
  }

  location @proxy {
    include proxy_params;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;
    proxy_pass http://159.89.123.456:80;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
 }
}

この問題の原因と解決方法について、ご教示いただければ幸いです。以下は nginx の error.log です。

2018/02/19 06:56:22 [debug] 3499#3499: *1 http upstream request: "/favicon.ico?"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http upstream process header
2018/02/19 06:56:22 [debug] 3499#3499: *1 malloc: 00005575AE6DABF0:4096
2018/02/19 06:56:22 [debug] 3499#3499: *1 recv: fd:11 424 of 4096
2018/02/19 06:56:22 [debug] 3499#3499: *1 http proxy status 400 "400 Bad Request"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http proxy header: "Server: nginx/1.10.3 (Ubuntu)"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http proxy header: "Date: Mon, 19 Feb 2018 06:56:22 GMT"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http proxy header: "Content-Type: text/html"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http proxy header: "Content-Length: 258"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http proxy header: "Connection: keep-alive"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http proxy header done
2018/02/19 06:56:22 [debug] 3499#3499: *1 xslt filter header
2018/02/19 06:56:22 [debug] 3499#3499: *1 **HTTP/1.1 400 Bad Request
Server: nginx/1.10.3 (Ubuntu)
Date: Mon, 19 Feb 2018 06:56:22 GMT
Content-Type: text/html
Content-Length: 258
Connection: keep-alive**

2018/02/19 06:56:22 [debug] 3499#3499: *1 write new buf t:1 f:0 00005575AE6DA880, pos 00005575AE6DA880, size: 166 file: 0, size: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 http write filter: l:0 f:0 s:166
2018/02/19 06:56:22 [debug] 3499#3499: *1 http cacheable: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 http proxy filter init s:400 h:0 c:0 l:258
2018/02/19 06:56:22 [debug] 3499#3499: *1 http upstream process upstream
2018/02/19 06:56:22 [debug] 3499#3499: *1 pipe read upstream: 1
2018/02/19 06:56:22 [debug] 3499#3499: *1 pipe preread: 258
2018/02/19 06:56:22 [debug] 3499#3499: *1 readv: 1, last:3672
2018/02/19 06:56:22 [debug] 3499#3499: *1 readv() not ready (11: Resource temporarily unavailable)
2018/02/19 06:56:22 [debug] 3499#3499: *1 pipe recv chain: -2
2018/02/19 06:56:22 [debug] 3499#3499: *1 pipe buf free s:0 t:1 f:0 00005575AE6DABF0, pos 00005575AE6DAC96, size: 258 file: 0, size: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 pipe length: 258
2018/02/19 06:56:22 [debug] 3499#3499: *1 input buf #0
2018/02/19 06:56:22 [debug] 3499#3499: *1 pipe write downstream: 1
2018/02/19 06:56:22 [debug] 3499#3499: *1 pipe write downstream flush in
2018/02/19 06:56:22 [debug] 3499#3499: *1 http output filter "/favicon.ico?"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http copy filter: "/favicon.ico?"
2018/02/19 06:56:22 [debug] 3499#3499: *1 image filter
2018/02/19 06:56:22 [debug] 3499#3499: *1 xslt filter body
2018/02/19 06:56:22 [debug] 3499#3499: *1 http postpone filter "/favicon.ico?" 00005575AE6DAA58
2018/02/19 06:56:22 [debug] 3499#3499: *1 write old buf t:1 f:0 00005575AE6DA880, pos 00005575AE6DA880, size: 166 file: 0, size: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 write new buf t:1 f:0 00005575AE6DABF0, pos 00005575AE6DAC96, size: 258 file: 0, size: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 http write filter: l:0 f:0 s:424
2018/02/19 06:56:22 [debug] 3499#3499: *1 http copy filter: 0 "/favicon.ico?"
2018/02/19 06:56:22 [debug] 3499#3499: *1 pipe write downstream done
2018/02/19 06:56:22 [debug] 3499#3499: *1 event timer: 11, old: 1519023442215, new: 1519023442222
2018/02/19 06:56:22 [debug] 3499#3499: *1 http upstream exit: 0000000000000000
2018/02/19 06:56:22 [debug] 3499#3499: *1 finalize http upstream request: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 finalize http proxy request
2018/02/19 06:56:22 [debug] 3499#3499: *1 free rr peer 1 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 close http upstream connection: 11
2018/02/19 06:56:22 [debug] 3499#3499: *1 free: 00005575AE6D5630, unused: 48
2018/02/19 06:56:22 [debug] 3499#3499: *1 event timer del: 11: 1519023442215
2018/02/19 06:56:22 [debug] 3499#3499: *1 reusable connection: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 http upstream temp fd: -1
2018/02/19 06:56:22 [debug] 3499#3499: *1 http output filter "/favicon.ico?"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http copy filter: "/favicon.ico?"
2018/02/19 06:56:22 [debug] 3499#3499: *1 image filter
2018/02/19 06:56:22 [debug] 3499#3499: *1 xslt filter body
2018/02/19 06:56:22 [debug] 3499#3499: *1 http postpone filter "/favicon.ico?" 00007FFDCA8F4CD0
2018/02/19 06:56:22 [debug] 3499#3499: *1 write old buf t:1 f:0 00005575AE6DA880, pos 00005575AE6DA880, size: 166 file: 0, size: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 write old buf t:1 f:0 00005575AE6DABF0, pos 00005575AE6DAC96, size: 258 file: 0, size: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 write new buf t:0 f:0 0000000000000000, pos 0000000000000000, size: 0 file: 0, size: 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 http write filter: l:1 f:0 s:424
2018/02/19 06:56:22 [debug] 3499#3499: *1 http write filter limit 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 writev: 424 of 424
2018/02/19 06:56:22 [debug] 3499#3499: *1 http write filter 0000000000000000
2018/02/19 06:56:22 [debug] 3499#3499: *1 http copy filter: 0 "/favicon.ico?"
2018/02/19 06:56:22 [debug] 3499#3499: *1 http finalize request: 0, "/favicon.ico?" a:1, c:1
2018/02/19 06:56:22 [debug] 3499#3499: *1 set http keepalive handler
2018/02/19 06:56:22 [debug] 3499#3499: *1 http close request
2018/02/19 06:56:22 [debug] 3499#3499: *1 http log handler
2018/02/19 06:56:22 [debug] 3499#3499: *1 posix_memalign: 00005575AE6DBC00:4096 @16
2018/02/19 06:56:22 [debug] 3499#3499: *1 free: 00005575AE6DABF0
2018/02/19 06:56:22 [debug] 3499#3499: *1 free: 00005575AE6E6F80, unused: 5
2018/02/19 06:56:22 [debug] 3499#3499: *1 free: 00005575AE6D9BE0, unused: 80
2018/02/19 06:56:22 [debug] 3499#3499: *1 free: 00005575AE6DBC00, unused: 3786
2018/02/19 06:56:22 [debug] 3499#3499: *1 free: 00005575AE6F63E0
2018/02/19 06:56:22 [debug] 3499#3499: *1 hc free: 0000000000000000 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 hc busy: 0000000000000000 0
2018/02/19 06:56:22 [debug] 3499#3499: *1 reusable connection: 1
2018/02/19 06:56:22 [debug] 3499#3499: *1 event timer add: 3: 65000:1519023447222
2018/02/19 06:56:22 [debug] 3499#3499: *1 post event 00005575AE7393C0
2018/02/19 06:56:22 [debug] 3499#3499: *1 delete posted event 00005575AE7393C0
2018/02/19 06:56:22 [debug] 3499#3499: *1 http keepalive handler
2018/02/19 06:56:22 [debug] 3499#3499: *1 malloc: 00005575AE6F63E0:1024
2018/02/19 06:56:22 [debug] 3499#3499: *1 recv: fd:3 -1 of 1024
2018/02/19 06:56:22 [debug] 3499#3499: *1 recv() not ready (11: Resource temporarily unavailable)
2018/02/19 06:56:22 [debug] 3499#3499: *1 free: 00005575AE6F63E0
2018/02/19 06:56:22 [debug] 3499#3499: *21 http keepalive handler
2018/02/19 06:56:22 [debug] 3499#3499: *21 malloc: 00005575AE6F63E0:1024
2018/02/19 06:56:22 [debug] 3499#3499: *21 recv: fd:12 0 of 1024
2018/02/19 06:56:22 [info] 3499#3499: *21 client 159.89.139.178 closed keepalive connection
2018/02/19 06:56:22 [debug] 3499#3499: *21 close http connection: 12
2018/02/19 06:56:22 [debug] 3499#3499: *21 event timer del: 12: 1519023447222
2018/02/19 06:56:22 [debug] 3499#3499: *21 reusable connection: 0
2018/02/19 06:56:22 [debug] 3499#3499: *21 free: 00005575AE6F63E0
2018/02/19 06:56:22 [debug] 3499#3499: *21 free: 00005575AE6F67F0, unused: 128
2018/02/19 06:57:27 [debug] 3499#3499: *1 event timer del: 3: 1519023447222
2018/02/19 06:57:27 [debug] 3499#3499: *1 http keepalive handler
2018/02/19 06:57:27 [debug] 3499#3499: *1 close http connection: 3

Answer 1

Michael Hampton が述べたように、設定が不自然です。このブロック:

location / {
  try_files $uri @proxy;
}

nginxに/var/www/htmlが存在する場合はそこからファイルを提供するように指示し、存在しない場合はリクエストをプロキシします。http://159.89.123.456:80（それ自体に）、存在しないファイルに対する無限再帰につながる