OK, as I expected.
Your docker container is also still running as it seems, please make sure to stop all Mattermost related docker containers (using the docker compose command you used to start them; docker ps should not show any running containers for Mattermost anymore (neither the database, nor nginx, nor the mattermost application itself). Then, make sure to stop the docker container that uses port 80, since we will need to run the certificate creation again. Once that’s all done (please verify, that no containers are running anymore), proceed with the following steps:
cd /home/jpzone282/mattermost
rm -r certs
./scripts/issue-certificate.sh -d mattermost.mysebsite.com -o ${PWD}/certs
If this all worked, please try to run the following command again:
CERT=$(awk -F= '$1~/^CERT_PATH/ { print $2 }' .env); find $CERT; file $CERT; ls -l $CERT; head -3 $CERT
The output should look different now and there should not be any error messages. On a working system, the output should be similar to this:
./volumes/web/cert/cert.pem
./volumes/web/cert/cert.pem: PEM certificate
-rw-r--r-- 1 2000 2000 5595 May 18 07:33 ./volumes/web/cert/cert.pem
-----BEGIN CERTIFICATE-----
MIIFJzCCBA+gAwIBAgISBGaFi17tXWztClOAzmqFkLPWMA0GCSqGSIb3DQEBCwUA
MDIxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MQswCQYDVQQD
If it matches what you see (except for the timestamps and the certificate data, of course), you can try to start the Mattermost containers using the docker compose command again.
Hopefully this is the last thing that was broken in your deployment.