aws-sfn-builder 0.0.4

AWS Step Functions State Machine boilerplate generator.

I was too lazy to set all the Next’s and End’s so I wrote this.

The state machines that I have in mind are pretty simple. They are a combination of sequences and parallelisations.

raw = [
    # Step can be declared just as a simple string
    "a",

    # Or you can provide all the details you know
    {
        "Name": "b",  # used for the name of the state, but removed from the state body
        "Type": "Pass",
        "Result": "b-result",
    },

    # c1 and c2 can run in parallel with d:
    [
        ["c1", "c2"],
        ["d"],
    ],
]

Make this into a State machine definition with Machine.parse(raw).to_json().

If you need to customise the compiled dictionaries, you can pass state_visitor= keyword argument to to_json (or to compile()). State visitor is a function that takes two positional arguments: the object representing the state, and the dictionary that we have compiled to represent the state in the state machine definitionas expected by AWS.

Here’s a result of Machine.parse(raw).to_json():

{
    "StartAt": "a",
    "States": {
        "a": {
            "Type": "Task",
            "Next": "b"
        },
        "b": {
            "Type": "Pass",
            "Next": "f1ba541c-632b-4a7e-94c4-7aaf60dde8cd",
            "Result": "b-result"
        },
        "f1ba541c-632b-4a7e-94c4-7aaf60dde8cd": {
            "Type": "Parallel",
            "End": true,
            "Comment": "f1ba541c-632b-4a7e-94c4-7aaf60dde8cd",
            "Branches": [
                {
                    "StartAt": "c1",
                    "States": {
                        "c1": {
                            "Type": "Task",
                            "Next": "c2"
                        },
                        "c2": {
                            "Type": "Task",
                            "End": true
                        }
                    }
                },
                {
                    "StartAt": "d",
                    "States": {
                        "d": {
                            "Type": "Task",
                            "End": true
                        }
                    }
                }
            ]
        }
    }
}