Nginx 502 error

Sorry for the issue spam… This time, I’ve done a decent amount of research and haven’t found any answer. Now that I’ve installed PowerDNS-Admin and everything appears to be running, when I go to powerdns.domain.com, I’m receiving a 502 error. This error is in /var/log/nginx/powerdns-admin.local.error.log:

cat /var/log/nginx/powerdns-admin.local.error.log 
2020/02/05 05:31:07 [crit] 2680#2680: *1 connect() to unix:/opt/web/powerdns-admin/powerdns-admin.sock failed (2: No such file or directory) while connecting to upstream, client: 10.9.0.241, server: powerdns.domain.com, request: "GET / HTTP/1.1", upstream: "http://unix:/opt/web/powerdns-admin/powerdns-admin.sock:/", host: "powerdns.domain.com"

I’m assuming this might be because on another guide I had to follow to get even this far, I was told to disable /etc/resolv.conf. After every command, I was receiving an error about not being able to resolve powerdns (hostname of the server). I added it back and set the nameserver back to 127.0.0.1 with option edns0.

cat /etc/hosts

127.0.0.1	localhost.localdomain	localhost
::1		localhost6.localdomain6	localhost6

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
### The following lines, Josh entered
127.0.0.1	powerdns.domain.com	powerdns
127.0.0.1	pdns.domain.com		pdns

Nginx Config:

server {
  listen *:80;
#  server_name               powerdns-admin.example.com www.powerdns-admin.example.com;
  server_name               powerdns.domain.com www.powerdns.domain.com;
  index                     index.html index.htm index.php;
  root                      /opt/web/powerdns-admin;
  access_log                /var/log/nginx/powerdns-admin.local.access.log combined;
  error_log                 /var/log/nginx/powerdns-admin.local.error.log;

  client_max_body_size              10m;
  client_body_buffer_size           128k;
  proxy_redirect                    off;
  proxy_connect_timeout             90;
  proxy_send_timeout                90;
  proxy_read_timeout                90;
  proxy_buffers                     32 4k;
  proxy_buffer_size                 8k;
  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_headers_hash_bucket_size    64;

  location ~ ^/static/  {
    include  /etc/nginx/mime.types;
    root /opt/web/powerdns-admin/app;

    location ~*  \.(jpg|jpeg|png|gif)$ {
      expires 365d;
    }

    location ~* ^.+.(css|js)$ {
      expires 7d;
    }
  }

  location / {
    proxy_pass            http://unix:/opt/web/powerdns-admin/powerdns-admin.sock;
    proxy_read_timeout    120;
    proxy_connect_timeout 120;
    proxy_redirect        off;
  }
}

Thoughts? I’m finally so close to having this up and running… If it means anything, on my client machine, I modified the hosts file to point to the server’s IP using it’s hostname. I currently don’t have an internal DNS server. Going to the server’s IP address brings up the default Nginx web page.

[Grommor]

@joshbgosh10592 Hi I encountered a similar problem, solved when I put the nginx config and official documentation ( see close to proxy_pass directive ) https://github.com/ngoduykhanh/PowerDNS-Admin/wiki/Running-PowerDNS-Admin-on-Ubuntu-or-Debian But I encountered another error PermissionError: [Errno 13] Permission denied: '/opt/web/powerdns-admin/powerdnsadmin/static/.webasset

helped crutch in the form of chmod 777 in the powerdnsadmin folder, maybe who knows the answer why this happens

[Mandarnold]

Hi, I had the same issue in nginx error.log -> “upstream prematurely closed connection while reading response header from upstream”. In the howtoforge - tutorial for installing powerdns-admin there is a step to change permissions on the application root directory to user www-data. And after configure the systemd service there is a step to change the permissions on the sub-directory <root-path>/powerdnsadmin to user: pdns. It’s important to do these steps in the right order, otherwise you’ll get the upstream-error from nginx.