HTTPS Certificate expiration issues

This is an article that was previously configured with a certificate, and a valid article that updates the certificate

The recent Web site's HTTPS certificate has expired, resulting in the inability to provide services externally, with the suspicion that the Automatic Updates configured at that time did not work.

Then to the background to update the HTTPS certificate, but encountered a problem, the use of specific commands and error messages:

sudo certbot renew--dry-run

Set the ' server_name ' directive to use the Nginx installer. Skipping

It seems that automatic update is not possible, continue the new method

1.sudo Service Nginx Stop

This will stop the Nginx service in advance, so as not to be able to update later because of occupation

2.sudo Certbot--force-renewal

Performing this step will force the update of the certificate, there will be an option in the process, which one is forgotten, it will need to be confirmed in the future. After the execution of this command, 2 more files were released Cloudappservice.top-001/fullchain.pem cloudappservice.top-001/ Privkey.pem. In fact, this time to see the reverse proxy file we configured before, the two latest files have been automatically updated to replace the original certificate file.

3. Restart the Nginx service

sudo cerbot nginx start

At this point, it is already possible for me to visit my website again. Just explain why the configuration of the previously configured Automatic Update certificate is not in effect?

HTTPS Certificate expiration issues