Cannot submit DNS name

I just installed Nextcloud AIO via Docker, when I open browser and type servername and click submit to continue installation, but got error:
DNS config is not set for this domain or the domain is not a valid domain! (It was found to be set to ‘’)

Do you know how can I fix the issue?

Hi, what are the dns records of your domain? Is an A record set or only an AAAA record?

Hi Szaimen,
I have setup in my Ubuntu host /etc/hosts: and ping is work.

So your means I need add the A record in my DNS server?

Thank you.

Yes, correct :+1:

Thank you Szaimen, just added the A record in my DNS server, it works.

Thank you so much.

1 Like

No problem at all!

Hi Szaimen,
Sorry for the trouble, another question:
I’d like running Nextcloud in my internal network, so when I added a internal A record in my local DNS Server and type Nextcloud servername: then click submit, I got error:
It seems like the ip-address is set to an internal or reserved ip-address. This is not supported. (It was found to be set to ‘’)

So that means I cannot using internal IP address for Nextcloud and must be use public IP address?

Thank you again.

Yes. However you may have a look at this: add documentation how to get it running locally (without opening NC to the public) · Issue #878 · nextcloud/all-in-one · GitHub

Hi Szaimen,
Thanks for your replied.
I am a newbie for Docker so the question is stupid, I checked the document as you mentioned, for options 1:
" 1. run aio behind a reverse proxy only open port 80, the domain that you want to use needs to point to your public ip-address, do not open port 443, set up a dns-server like pi-hole and use it as dns-server in your network, set a custom dns record for this domain and point it to the internal ip-address of your reverse proxy, set the dns-server in docker-config.json to the internal ip of the dns server → now everything should work."

Do you know how to find and modify the file “docker-config.json” ?

Sorry for the trouble, thank you.

I tried to remove containers and running:

sudo docker run -it \
--name nextcloud-aio-mastercontainer \
--restart always \
-p 8080:8080 \
-e APACHE_PORT=11000 \
--volume nextcloud_aio_mastercontainer:/mnt/docker-aio-config \
--volume /var/run/docker.sock:/var/run/docker.sock:ro \

Also I use Nginx as reverse proxy in my Ubuntu server and the configuration is:
server {
    listen 80;
    location / {
             proxy_pass          http://localhost:11000;
             rewrite ^/server/(.*) /$1 break;
             proxy_set_header        Host $host;
             proxy_set_header        X-Real-IP $remote_addr;
             proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
             client_max_body_size 0;

             # Websocket
             proxy_http_version 1.1;
             proxy_set_header Upgrade $http_upgrade;
            # proxy_set_header Connection $connection_upgrade;

I commented "proxy_set_header Connection $connection_upgrade" because if I added it will got error:
[emerg] 201866#201866: unknown "connection_upgrade" variable

So when I access from browser I got the code as below:


Another questions: Can I install reverse proxy and Nextcloud AIO in the same server? AIO is as containers, Nginx reverse proxy not container.

I don't know what went wrong.

See docker-compose examples for reverse proxies · Discussion #588 · nextcloud/all-in-one · GitHub for a more complete nginx conf example