Check end date SSL certificate (for letsencrypt)

check-cert.sh

#!/bin/sh

# Check end date certificate
# Using: script.sh example.net

DOMAIN=$1
CERT_DOWNLOAD_PATH=/tmp
PORT=443
ALERT_TIME=604800 # 7 days

CERT="$CERT_DOWNLOAD_PATH/$DOMAIN.pem"

if [ ! -f "$CERT" ]; then
    openssl s_client -connect "$DOMAIN:$PORT" 1> "$CERT" 2>/dev/null
fi

if openssl x509 -checkend "$ALERT_TIME" -noout -in "$CERT"; then
    echo "Valid - $(openssl x509 -noout -in $CERT -enddate)"
    exit 0
else
    echo 'Need renew'
    exit 1
fi