Example Derived Image Solution for Ignition

This solution provides an example of how to implement a derived Ignition Docker image with the following features:

• Adding third-party modules such as MQTT Engine and Azure Injector.
• Bundling an integrated gateway backup.
• Setting default username and password of default built-in user source.
• Shimming the entrypoint script with a spot to introduce custom functionality to run prior to launching the gateway.

How to Build

Before you get started, create a file called gw-secrets/GATEWAY_ADMIN_PASSWORD with the password that you want to associate with the admin user. There is special functionality built into the "prep" stage of the multi-stage build that updates the default user source from the built-in gateway backup with your desired baseline password. This is converted to a one-way salt+hash for storage in the gwbk.

There is a docker-compose.yml solution that can be used to build the image. You can build+run the image with:

docker compose up --build -d

Warning

The resultant gateway that will launch at http://localhost:8088 does not have a volume associated with it in order to assist with rapid testing of changes. Please add a volume definition to persist your gateway state data if you use this solution outside of testing the derived image build!

If you want to build the image with docker build, you can use something like the command below:

docker build \
    --build-arg IGNITION_VERSION=8.1.26 \
    --build-arg SUPPLEMENTAL_MODULES="azureiotinjector mqttengine" \
    --secret id=gateway-admin-password,src=gw-secrets/GATEWAY_ADMIN_PASSWORD \
    -t myimage:mytag \
    gw-build