Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
First of all, I am setting up a gitlab sever in my office, I encounted a DNS problem while installing certbot.
My domain is: caop-server.calcomp.com.tw
I ran this command: sudo certbot certonly --standalone
It produced this output:
sean@opsw-server:~$ sudo certbot certonly --standalone
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Please enter the domain name(s) you would like on your certificate (comma and/or
space separated) (Enter 'c' to cancel): caop-server.calcomp.com.tw
Requesting a certificate for caop-server.calcomp.com.tw
Could not bind TCP port 80 because it is already in use by another process on
this system (such as a web server). Please stop the program in question and then
Certbot failed to authenticate some domains (authenticator: standalone). The Cer tificate Authority reported these problems:
Detail: DNS problem: NXDOMAIN looking up A for caop-server.calcomp.com.tw - check that a DNS record exists for this domain; DNS problem: NXDOMAIN looking up AAAA for caop-server.calcomp.com.tw - check that a DNS record exists for this domain
Hint: The Certificate Authority failed to download the challenge files from the temporary standalone webserver started by Certbot on port 80. Ensure that the listed domains point to this machine and that it can accept inbound connections from the internet.
Some challenges have failed.
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot with -v for more details.
My web server is (include version): Nginx for Gitlab
The operating system my web server runs on is (include version):
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don't know): Yes
I'm using a control panel to manage my site (no, or provide the name and version of the control panel):
The version of my client is (e.g. output of
certbot --version or
certbot-auto --version if you're using Certbot):
I am a new guy for programming, thanks for your help.