Nginxの起動時に警告とエラー「the “ssl” directive is deprecated」「duplicate default server」

事象

nginxをリバースプロキシとして起動。マルチサイトのため、２つのconfファイルを配置。

• /etc/nginx/conf.d/dc.conf
• /etc/nginx/conf.d/fx.conf

dc_proxy | nginx: [warn] the "ssl" directive is deprecated, use the "listen ... ssl" directive instead in /etc/nginx/conf.d/dc.conf:6

dc_proxy | nginx: [emerg] a duplicate default server for 0.0.0.0:443 in /etc/nginx/conf.d/fx.conf:3

原因

cat proxy/etc/nginx/conf/dc.conf

3行目のlisten 443 default_server ssl;　と　6行目のssl on;　が被ってる

server{

    listen 443 default_server ssl;
    server_name dc.xxxxxxxxxx.com;

    ssl on;
    ssl_certificate     /etc/letsencrypt/live/xxxxxxxxxx.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/xxxxxxxxxx.com/privkey.pem;

    proxy_redirect off;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    location / {
        proxy_pass   http://dc:8100;
    }

    location ^~ /.well-known/acme-challenge/ {
        allow all;
        root /var/www/html;
        try_files $uri =404;
    }

}

cat proxy/etc/nginx/conf/fx.conf

server{

    listen 443 default_server ssl;
    server_name fx.xxxxxxxxxx.com;

    ssl on;
    ssl_certificate     /etc/letsencrypt/live/xxxxxxxxxx.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/xxxxxxxxxx.com/privkey.pem;

    proxy_redirect off;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    location / {
        proxy_pass   http://fx:8000;
    }

    location ^~ /.well-known/acme-challenge/ {
        allow all;
        root /var/www/html;
        try_files $uri =404;
    }

}

対応

confファイルを書き換え

• 3行目のlisten 443 default_server ssl;　→ listen 443;
• 6行目のssl on;　削除するとつかなくなるので、警告はそのままにしておく

/etc/nginx/conf.d/dc.conf

server{

    listen 443;
    server_name dc.xxxxxxxxxx.com;

    ssl on;
    ssl_certificate     /etc/letsencrypt/live/xxxxxxxxxx.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/xxxxxxxxxx.com/privkey.pem;

    proxy_redirect off;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    location / {
        proxy_pass   http://dc:8100;
    }

    location ^~ /.well-known/acme-challenge/ {
        allow all;
        root /var/www/html;
        try_files $uri =404;
    }

}

• /etc/nginx/conf.d/fx.conf

server{

    listen 443;
    server_name fx.xxxxxxxxxx.com;

    ssl on;
    ssl_certificate     /etc/letsencrypt/live/xxxxxxxxxx.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/xxxxxxxxxx.com/privkey.pem;

    proxy_redirect off;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    location / {
        proxy_pass   http://fx:8000;
    }

    location ^~ /.well-known/acme-challenge/ {
        allow all;
        root /var/www/html;
        try_files $uri =404;
    }

}                                                                                                                               

[2019/09/29 追記]
nginxの使い方（confの書き方)など、なんとなくで使っているので、
いちど体系的に理解したいと考えていました。
nginxのことがよくまとめられている「nginx実践入門」という本を見つけたので共有します。
この一冊、いままでコピペしてきたことが理解できる、なかなかの良著です。

nginx実践入門（技術評論社）