crowsnest-processor-ais-decode

A processing microservice within the crowsnest ecosystem which accepts raw AIS messages as input and produces AIS messages in json struct format.

The microservice:

1. Subscribes to the crowsnest mqtt broker and expects incoming envelopes according to the following format:

   {
       "sent_at": ...,
       "message": "IUFJVkRNLDEsMSwsQSwxM3U9UjFQMDAwUG5McEpRMFNKODNsPDIwODBRLDAqNUY="    # base64-encoded AIS message
   }

2. Assembles multiline messages and decodes to json structs according to the format defined by pyais, see here
3. Publishes jsonified AIS messages to the same crowsnest mqtt broker on the topic format .../{mmsi}/{message_type} according to the following format:

   {
       "sent_at": ...,
       "message": "{jsonified AIS messages}"
   }

Development setup

To setup the development environment:

python3 -m venv venv
source ven/bin/activate

Install everything thats needed for development:

pip install -r requirements_dev.txt

In addition, code for brefv must be generated using the following commands:

mkdir brefv
datamodel-codegen --input brefv-spec/envelope.json --input-file-type jsonschema --output brefv/envelope.py
datamodel-codegen --input brefv-spec/messages --input-file-type jsonschema  --reuse-model --output brefv/messages

To run the linters:

black main.py tests
pylint main.py

To run the tests:

python -m pytest --verbose tests

License

Apache 2.0, see LICENSE