MJML docker microservice / server

Standalone mjml server, listening on port 80/tcp.

Due to various challenges this image sports the following features:

• Clean and fast shutdowns on docker.
• Simple CORS capabilities.
• Small footprint (at least in a npm way).
• Supports healthchecks.

Table of contents

• Overview
• Defaults
• Development
• Troubleshooting

Overview

This image spools up a simple mjml server instance, listening to port 80/tcp per default.

Due to GDPR / DSGVO reasons I required the mjml instance to be under my own control, as the processing personal information is processed in mail content generation.

Starting the image is as easy as running a test instance through docker

docker run -it --rm -p 8889:80 mjml-server

or docker-compose with the following example:

version: '3.7'

services:
  mjml:
    image: adrianrudnik/mjml-server
    ports:
      - 8889:80
    # for development, uncomment the following lines:
    # environment:
    #   - CORS=*
    #   - MJML_KEEP_COMMENTS=true
    #   - MJML_VALIDATION_LEVEL=strict
    #   - MJML_MINIFY=false

Defaults

The production defaults, without any override, default to:

CORS ""
MJML_KEEP_COMMENTS "false"
MJML_VALIDATION_LEVEL "soft"
MJML_MINIFY "true"

Development

For development environments I would suggest to switch it to

CORS "*"
MJML_KEEP_COMMENTS "true"
MJML_VALIDATION_LEVEL "strict"
MJML_MINIFY "false"

This will escalate any issues you have with invalid mjml code to the docker log (stdout or docker-compose logs).

Troubleshooting

Make sure you pass along a plain Content-Type header and pass the mjml as raw body.

Catch errors by looking at the HTTP response code.