Mail sender agent
sudo apt install swaks
Sample
swaks --to fatlan@sysadmin.tr --from "alert@sysadmin.tr" --server mail.fatlan.com --port 587 --auth LOGIN --auth-user "alert@sysadmin.tr" --auth-password "password" -tls --header "Subject:test" --body "test" --hide-all
For 7 day(604800 seconds)
NoTe: Must be openssl version 1.1 (otherwise openssl -checkend does not work)
Check ceritficate expiration openssl sample1 for certificate pem file
openssl x509 -enddate -noout -in "/fatlancom/certificate.pem" -checkend "604800" | grep -q 'Certificate will expire'
Check ceritficate expiration openssl sample2 for domain
echo | openssl s_client -servername fatlan.com -connect fatlan.com:443 | openssl x509 -noout -dates -checkend "604800"
Check everyday at 00:00 sample for scripts
crontab -e
0 0 * * * bash /fatlancom/ssl-expire-alert.sh >2 /dev/null