SSL Certificate expiration check

This simple script checks for SSL certificates about to expire and optionally sends an email if the check fails.

Using

Check the expiration of a certificate like this:

docker run -e DOMAINS=example.com mobilejazz/certcheck

Configuration variables:

• MARGIN_DAYS: how many days of margin you want before getting a warning for a certificate about to expire (default 6)
• DOMAINS: list of domains to verify separated by spaces (for example: example.com anotherdomain.com). Either DOMAINS or DOMAINS_FILE must be provided (and only one of the two).
• DOMAINS_FILE: a file containing the domains to check (for example: domains.txt). Either DOMAINS or DOMAINS_FILE must be provided (and only one of the two).
• MAIL_TO: email to send notifications to (default: none). You will need to configure msmtp by providing an /etc/msmtprc file

You can see a more complex usage example in docker-compose.yml, which configures msmtp to send mail using Amazon SES and checks a list of domains periodically using the funkyfuture/deck-chores image.

Building

If you want to edit the image, you can rebuild it like this:

docker build -t mobilejazz/certcheck .