pOut is a printer for Protocol Buffers. It can read from stdin or files and produce bytes printed to Stdout. These can then be piped to other programs. Using Protocol Buffers in this way enables rapid development and debugging, a faster feedback cycle, and

Features

• Protobuf or JSON input

• can be piped into too, so you can do neat things like pipe a cURL response directly into pOut and into your program

• Detection of Protobuf types with standard protobuf layouts

Installation & Requirements

• Protoc - I am working on using buf to remove this dependency and hardcode this into the binary

brew cask install pout

Background & Motivation

• Protobuf is a large and complex project, with many touchpoints. However, to get off the ground, or to try new things requires a lot of cognitive load.
• It is really hard to hack with protobuf, there are so many things to compile
• type and folder structure layouts can often be confusing to beginners, and it becomes cumbersome to operate a script-first approach to your code
• gRPC is a great tool, but because of the typed nature it is often hard to debug. It's not as easy as you think to load up a server and simply send a few commands to it. There are 'curl' options, but it becomes complicated to send messages there.
• compiling Protoc Buffers can break flow, especially if you want to test data types
• you can use pOut with gRPC curl
• protobuf can be used without gRPC, for instance, message queues can be hard to test
• pOut is designed to take slightly longer to process a file, but make it super simple to get going.
• lots of proto files means lots of cognitive overhead
• If you follow common folder structures the process becomes much easier
• The new protocol buffers Go layout enabling easy reflection https://blog.golang.org/protobuf-apiv2
• UNIX philosophy of extremely small programs. pOut in combination with pIn allow you to chain many commands together.

Usage There are 3 variables that any system needs to resolve a proto type:

1. the base path of the protos, this is assumed to be 'protos' in the current directory. There are overrides available

pout [flags] [args] [--] Here are the variables you can pass in, conflicts are resolved in order of priority (highest priority overrides options from lower priority):

Flags: Resolving the message: -I A proto base path -f A proto file & package

Environment Variables: PROTO_PATH=/path/to/protos

Args: [package.message name] A message name, prefixed with its package in the notation Input "--" will take the input from stdin [filename] - will load a json or .pb file in -

pOut will find the first message name in any of the packages you supply.

Examples NodeJS Python Go cURL pout swapi.Person ./fixtures/people/luke_skywalker.json

check the /examples folder for more!

Notes

Thank you to the excellent GoReleaser package, which allows releases, including protoc builds, to be automated for lots of operating systems.