Docker Image for Sending Email
Docker image for sending emails over SMTP.
Using a docker image means that a system with docker can send emails without installing dependencies on the system itself.
The underlying code is basic PHP that uses PHPMailer to do the hard work.
Environment Variables
The SMTP config is currently set via environment variables.
This allows the flexibility of using an env file (with --env-file=<file>) and/or individual env arguments
(with -e=<envvar>) when invoking on CLI.
This obviously comes with the benefit of being able to create a container which can be rerun, e.g. for a system notification.
SMTP Config
SMTP_HOST=smtp.ionos.co.uk
SMTP_POST=587
SMTP_USER=noreply@example.co.uk
SMTP_PASS=password
Mail Options
MAIL_FROM=noreply@example.co.uk
MAIL_TO=you@example.co.uk
MAIL_SUBJECT=System Mail
The email body is currently read from stdin, as the body is expected to be piped in, for instance to send the output from running a command.
Running with Docker
echo "Hello" | docker run --rm -i --env-file=.env jbuncle/docker-mailer
Real World Example
I created this image so that I could run a regular security audit on system which I didn't want to add mail dependencies to.
Using lynis I can setup a cronjob to run a security audit and email me the results.
lynis --no-log --no-colors audit system | docker run --rm -i --env-file=.env jbuncle/docker-mailer