Eliona App to access Thingdust spaces

This Eliona app for Thingdust spaces enables the communication of data from Thingdust spaces to the Eliona environment.

The app collects data from configurable endpoints. Each thingdust space is automatically assigned to an eliona asset when a new endpoint is configured. Data from each space (e.g temperature, humidity and occupancy) can then be transferred to and displayed in eliona.

Configuration

The app needs environment variables and database tables for configuration. To edit the database tables the app provides an own API access.

Registration in Eliona

To start and initialize an app in an Eliona environment, the app has to be registered in Eliona. In order to register the app, an entry in the database table public.eliona_app must be made.

Environment variables

• CONNECTION_STRING: configures the Eliona database. Otherwise, the app can't be initialized and started (e.g. postgres://user:pass@localhost:5432/iot).

• INIT_CONNECTION_STRING: configures the Eliona database for app initialization like creating schema and tables (e.g. postgres://user:pass@localhost:5432/iot). Default is content of CONNECTION_STRING.

• API_ENDPOINT: configures the endpoint to access the Eliona API v2. Otherwise, the app can't be initialized and started. (e.g. http://api-v2:3000/v2)

• API_TOKEN: defines the secret to authenticate the app and access the API.

• API_SERVER_PORT(optional): define the port the API server listens. The default value is Port 3000.

• LOG_LEVEL(optional): defines the minimum level that should be logged. Not defined the default level is info.

Database tables

The app requires configuration data that remains in the database. In order to do this, the app creates its own database schema thingdust during initialization. To modify and handle the configuration data the app provides an API access. Take a look at the API specification to see how the configuration tables should be used.

• thingdust.config: contains the thingdust API endpoints. Each row contains the specification of one endpoint(i.e config id, url, key, polling intervals etc.)

• thingdust.spaces: contains the mapping from each space uniquely defined by its configuration and project id to an eliona asset. Each row contains the specification of one endpoint(i.e config id, url, key, polling intervals etc.) The app collects and writes data separately for each configured project. The mapping is created automatically by the app.

Generation: to generate access method to database see Generation section below.

References

App API

The thingdust app provides its own API to access configuration data and other functions. The full description of the API is defined in the openapi.yaml OpenAPI definition file.

• API Reference shows details of the API.

Generation: to generate api server stub see Generation section below.

Eliona Assets

The app creates necessary asset types and attributes during initialization. See eliona/asset-type-thingdust_space.json for details.

The thindust app writes data for each thingdust space to the eliona database. Each thingdust space is mapped to an asset with attributes: temperature, humidity and occupancy. All attributes are of the eliona subtype Input.

Tools

Generate API server stub

For the API server the OpenAPI Generator for go-server is used to generate a server stub. The easiest way to generate the server files is to use one of the predefined generation script which use the OpenAPI Generator Docker image.

.\generate-api-server.cmd # Windows
./generate-api-server.sh # Linux

Generate Database access

For the database access SQLBoiler is used. The easiest way to generate the database files is to use one of the predefined generation script which use the SQLBoiler implementation. Please note that the database connection in the sqlboiler.toml file have to be configured.

.\generate-db.cmd # Windows
./generate-db.sh # Linux