Message Composer

Name	Message Composer
Version	v1.1.0
Dockerhub Link	weevenetwork/message-composer
authors	Jakub Grzelak

• Message Composer
  • Description
    • Supported Utils Functions
  • Environment Variables
    • Module Specific
    • Set by the weeve Agent on the edge-node
  • Dependencies
  • Input
  • Output

Description

This module enables a customized composition of messages, in example alert messages that can be later passed to the next module like Slack Alert which would further pass it to the selected Slack endpoint channel. To include some data in the message use double curly brackets and provide a desired label like {{ label_name }}. To use one of the supported utils functions to add extra information to your message, use double curly brackets and prefix utils. before the name of the function you want to apply {{ utils.function_name }} (see Supported Utils Functions section below).

For instance, if we expect to receive data in the following format:

{
    "temperature": 12,
    "volume": 375,
    "location": "Berlin"
}

and if we have our Message Label set to alertMessage and our Message Content variable is set to the following:

Device {{utils.getNodeName}} (in {{location}}) measured temperature {{temperature}} on {{utils.getDateAndTime}}

then the output of the module will be:

{
    "alertMessage": "Device Kunbus (in Berlin) measured temperature 12 on 2022-09-25 15:35:17.31234"
}

Supported Utils Functions

Function Name	Description
getNodeName	Returns the name of the node on which the module is running.
getNodeID	Returns the ID of the node on which the module is running.
getDateAndTime	Returns the current date and time in the following format: YYYY-MM-DD HH:MM:SS.mmmmmm.
getDate	Returns the current date in the following format: YYYY-MM-DD.
getTime	Returns the current time in the following format: HH:MM:SS.mmmmmm.
getTimestamp	Returns the number of seconds since the Unix epoch.

Environment Variables

Module Specific

The following module configurations can be provided in a data service designer section on weeve platform:

Name	Environment Variables	type	Description
Message Content	MESSAGE_CONTENT	string	Message content. Use double curly brackets to access labels from your data (i.e. to access data assigned to temperature label use {{temperature}}).
Message Label	MESSAGE_LABEL	string	Label to assign message to in the output JSON object.

Set by the weeve Agent on the edge-node

Other features required for establishing the inter-container communication between modules in a data service are set by weeve agent.

Environment Variables	type	Description
MODULE_NAME	string	Name of the module
MODULE_TYPE	string	Type of the module (Input, Processing, Output)
EGRESS_URLS	string	HTTP ReST endpoints for the next module
INGRESS_HOST	string	Host to which data will be received
INGRESS_PORT	string	Port to which data will be received

Dependencies

bottle
requests

Input

Input to this module is:

• JSON body single object, example:

{
    "temperature": 12,
    "volume": 375,
    "location": "Berlin"
}

Output

Output of this module is (assuming Message Content is Device {{utils.getNodeName}} (in {{location}}) measured temperature {{temperature}} on {{utils.getDateAndTime}})

• JSON body single object, example:

{
    "alertMessage": "Device Kunbus (in Berlin) measured temperature 12 on 2022-09-25 15:35:17.31234"
}