Protosaurus

Parse and create ProtoBuffer messages at runtime. Deserialize Protobuf from Kafka using kcat and a schema registry.

Installation

pip install protosaurus

Usage

Deserialize Protobuf from Kafka using a schema registry

If a schema registry is available, Protosaurus can deserialize Protobuf messages in Kafka automatically:

kcat -C -e -F <kafka.config> -t <topic> -f "%o\\n%k\\n%R%s" | protosaurus - --schema-registry <url>

Using pipx:

kcat -C -e -F <kafka.config> -t <topic> -f "%o\\n%k\\n%R%s" | pipx run protosaurus - --schema-registry <url>

Parse Proto in Python

Protosaurus can parse .proto definitions at runtime without using protoc. This allows Protobuf byte arrays to be converted to JSON and vice versa.

import json
from protosaurus import Context
from base64 import b64decode

# create a context which stores the proto schemas
ctx = Context()

# add protos by specifying name and content
ctx.add_proto('diet.proto',
    """
    syntax = "proto3";
    enum Diet {
        carnivorous = 0;
        herbivorous = 1;
    }
    """)

# the proto can be imported via the specified name
ctx.add_proto('animal.proto',
    """
    syntax = "proto3";
    import "diet.proto";
    message Animal {
        string name = 1;
        Diet diet = 2;
        double length = 3;
    }
    """)

# convert a message from base64 string...
data = ctx.to_json('Animal', b64decode('CglJZ3Vhbm9kb24QARkAAAAAAAAkQA=='))

# ...or hex string
data = ctx.to_json('Animal', bytes.fromhex('0a09496775616e6f646f6e1001190000000000002440'))

print(data)
# >>> '{"name":"Iguanodon","diet":"herbivorous","length":10}'


# convert json to protobuf
data = ctx.from_json('Animal', json.dumps({"name":"Iguanodon","diet":"herbivorous","length":10}))

print(data)
# >>> b'\n\tIguanodon\x10\x01\x19\x00\x00\x00\x00\x00\x00$@'