This script renews letsecnrypt SSL certificates using Cloudflare dns-1 renewal. It assumes you are using Mailcow.

certbot-dns-mailcow

#!/usr/bin/env bash
# This script renews letsecnrypt SSL certificates using Cloudflare dns-1 renewal
# It assumes you are using Mailcow
set -euo pipefail

# REQUIRED set these:
your_email=letsencrypt@your.domain
your_domain=mail.your.domain # only tested with single domain
cloudflare_ini_path=/root/.cloudflare # add your Cloudflare file here, called cloudflare.ini

# OPTIONAL also set these:
log_file=/var/log/certbot-cloudflare.log # if you don't want any logs, change it to /dev/null

# send all output and errors to log file
exec 1>$log_file
exec 2>&1

# log what we are doing
set -x

date # overwrite, no log rotate!
echo "starting renewal"

docker pull certbot/dns-cloudflare
docker run --rm \
    -v $cloudflare_ini_path/cloudflare.ini:/cloudflare.ini \
    -v /opt/mailcow-dockerized/data/assets/ssl:/etc/letsencrypt \
    certbot/dns-cloudflare \
    certonly -n --agree-tos -m $your_email \
    --dns-cloudflare --dns-cloudflare-credentials /cloudflare.ini \
    -d $your_domain

cd /opt/mailcow-dockerized/data/assets/ssl
newcerts=$(find live/$your_domain/ -mmin -5)
if [ -z "$newcerts" ]; then
    echo "no renewals found, not restarting services"
    exit
fi

ln -sfv live/$your_domain/privkey.pem key.pem
ln -sfv live/$your_domain/cert.pem cert.pem

cd ../../..

function reload_ssl_service () {
    service=$1
    port=$2
    echo "restarting SSL service $1 on port $2"
    docker-compose restart $service
    timeout 30 sh -c '\
        while ! \
        openssl s_client -showcerts -connect $0:$1 2>/dev/null </dev/null | openssl x509 -noout 2>/dev/null; do
        # $0 and $1 are inside single quotes, which means they expand to the arguments provided to sh -c
            sleep 1
        done' $your_domain $port
    echo "$service SSL cert expiration"
    openssl s_client -showcerts -connect $your_domain:$port 2>/dev/null </dev/null | openssl x509 -noout -text | grep 'Not After'
}
reload_ssl_service nginx-mailcow 443
reload_ssl_service dovecot-mailcow 993
reload_ssl_service postfix-mailcow 465

date
echo "completed"

Logs indicate all 3 have successfully restarted. Restarting manually didn't make any difference.

I think the issue is path related. Mailcow docs say not to use simlinks for certs.

Built in acme client places certs in to /data/assets/ssl/{domain.com}. It appears /data/assets/ssl is then mapped to the containers as /etc/ssl/mail. Your script symlinks them to /data/assets/ssl directly. From there it gets confusing.

Perhaps there's been some changes to cert placement in the current version. (2023-05a).

Edit. Rereading the mailcow docs - specifically https://docs.mailcow.email/post_installation/firststeps-ssl/#how-to-use-your-own-certificate

Does indeed indicate

---

To use your own certificates, just save the combined certificate (containing the certificate and intermediate CA/CA if any) to data/assets/ssl/cert.pem and the corresponding key to data/assets/ssl/key.pem.

IMPORTANT: Do not use symbolic links! Make sure you copy the certificates and do not link them to data/assets/ssl.

---

I'm not sure how /data/assets/ssl/{domain.com} got created in my instance to begin with. It does have a date of few weeks ago, so perhaps it was made by the built in acme client. So the only change then is copying files rather than symlinking?