[ERROR] no resolver defined to resolve

Nginx에 Jenkins 설정을 마치고 돌려봤지만 no resolver defined to resolve 라고 뜨는 에러가 발생했다.
1. 찾아보니 proxy_pass 를 변수로 받으면 nginx의 기본 built-in resolver로 연결을 하는데, 여기서 문제가 생긴 것임.
2. resolver 1.1.1.1; 를 추가하니 해결

• 수정한 default.conf

server {
    listen       80;
    listen  [::]:80;
    listen 443 ssl;
    listen [::]:443 ssl;

    server_name  j10a708.p.ssafy.io;

    # SSL setting
    ssl_certificate /etc/ssl/j10a708.p.ssafy.io/certificate.crt;
    ssl_certificate_key /etc/ssl/j10a708.p.ssafy.io/private.key;

    # redirect HTTP request to HTTPS request
    if ($scheme = http) {
        return 301 https://$server_name$request_uri;
    }

    #access_log  /var/log/nginx/host.access.log  main;
    #error_log /var/log/nginx/host.error.log;

    location /.well-known/pki-validation/ {
        alias /usr/share/nginx/html/.well-known/pki-validation/;
    }

    include /etc/nginx/conf.d/service-url.inc;

    location / {
        resolver 1.1.1.1;
        proxy_pass $service_url;
        #root   /usr/share/nginx/html;
        proxy_redirect off;
        #index  index.html index.htm;
        charset utf-8;

        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;

    }

    location /api {
        proxy_pass http://j10a708.p.ssafy.io:8080;
        proxy_redirect off;
        charset utf-8;

        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;
    }

    #error_page  404              /404.html;

    # redirect server error pages to the static page /50x.html
    #
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }
}

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