Drogue IoT – OPC UA server for the Doppelgänger Twin state

This is a standard Quarkus application, so the following sections only describe to most important aspects of running or building this application. All features that Quarkus provides do still apply.

Running

Either run this as a standard Java application, or using the native binary. The easiest way is to run this using a container, for example:

podman run --rm -ti -p 4840:4840 ghcr.io/drogue-iot/drogue-doppelgaenger-opcua-server:latest

However, you will need to provide some configuration. The simplest way is to create a .env file, and reference it during the startup:

podman run --rm -ti -p 4840:4840 --env-file=.env ghcr.io/drogue-iot/drogue-doppelgaenger-opcua-server:latest

If you want to run a locally built image, use:

podman run --rm -ti -p 4840:4840 --env-file=.env drogue-doppelgaenger-opcua-server

Configuration

The application cannot run without a configuration, as it needs to know the Doppelgaenger backend to use. You can provide the configuration in any way you can configure a Quarkus application.

Property	Type	Default
drogue.doppelgaenger.api The base URL to the Doppelgaenger API Environment variable: DROGUE_DOPPELGAENGER_API	URL
drogue.doppelgaenger.application The name of the application, in case of a multi-instance installation. Environment variable: DROGUE_DOPPELGAENGER_APPLICATION	String	default
quarkus.oidc-client.auth-server-url The URL to the OAuth2 instance used by the Doppelgaeanger instance. This instance is used in to acquire access tokens for the API. In case of Keycloak, this is most likely https://server/realms/<realm> Environment variable: QUARKUS_OIDC_CLIENT_AUTH_SERVER_URL	URL
quarkus.oidc-client.client-id The OAuth2 Client ID Environment variable: QUARKUS_OIDC_CLIENT_CLIENT_ID	String
quarkus.odic-client.credentials.secret The secret for the Client ID Environment variable: QUARKUS_OIDC_CLIENT_CREDENTIALS_SECRET	String

Additionally, there are some configuration options for the OPC UA server:

Property	Type	Default
drogue.doppelgaenger.opcua.bind-address The address to bind to. Environment variable: DROGUE_DOPPELGAENGER_OPCUA_BIND_ADDRESS	String	localhost
drogue.doppelgaenger.opcua.bind-port The port to bind to. Environment variable: DROGUE_DOPPELGAENGER_OPCUA_BIND_PORT	int	4840
drogue.doppelgaenger.opcua.hostnames The hostnames to announce. By default, it will try to auto-detect, based on the local interfaces and DNS. However, when running inside a container, you might need to override this, with an externally resolvable hostname. Environment variable: DROGUE_DOPPELGAENGER_OPCUA_HOSTNAMES	Set<String>	empty
drogue.doppelgaenger.opcua.enable-anonymous Enable anonymous access. Environment variable: DROGUE_DOPPELGAENGER_OPCUA_ENABLE_ANONYMOUS	boolean	false
drogue.doppelgaenger.opcua.users.<name> Add user/password based access. Multiple entries can be set, assigned value is the password. Environment variable: DROGUE_DOPPELGAENGER_OPCUA_USERS_<user>	boolean	false

A minimum .env file is:

DROGUE_DOPPELGAENGER_API=https://doppelgaenger-api

QUARKUS_OIDC_CLIENT_AUTH_SERVER_URL=https://keycloak/realms/doppelgaenger
QUARKUS_OIDC_CLIENT_CLIENT_ID=services
QUARKUS_OIDC_CLIENT_CREDENTIALS_SECRET=services-client-secret

Developing

You can start the application in developer mode using:

mvn compile quarkus:dev

Building

To build a new image, run:

mvn package
podman build . -f src/main/docker/Dockerfile.jvm -t drogue-doppelgaenger-opcua-server

To build the native image, run:

mvn package -Pnative
podman build . -f src/main/docker/Dockerfile.native