test-infra VS Protobuf

The trickiest part of decoding protobufs blind is how embedded messages and strings have the same tag type, but that's pretty easy to handle.

You can write a simple protobuf decoder in a couple hundred lines of code if you don't want to pull in the full protoc dependency: https://github.com/kubernetes/test-infra/blob/master/guberna... https://github.com/kubernetes/test-infra/blob/master/guberna...

Advanced tip: have a way for approved contributors to re-trigger CI. For example, Kubernetes, Kubeflow, and minikube use a tool called prow to run tests. Prow comes with a prow-bot that can accept different commands, automatically tagging issues or rerunning specific tests. Not for small projects, but this can alleviate maintainer headaches caused by trivial busy work.

It started as a small inside joke, but kinda just blew up. A bunch of us really loved UGG (which, if you haven’t played it, still highly recommend it even if you aren’t normally into video games), and as some of us have been known to do, take jokes a little too far/literal. A plug-in for the Kubernetes was built (https://github.com/kubernetes/test-infra/pull/14587) that posts goose pictures on command. Then there were some contests/activities put together at our contributor summit that were goose-themed.

Here's a minimal Python protobuf parser that can extract basic information in about 50 LOC.

https://github.com/kubernetes/test-infra/blob/master/guberna...

For at least 4 years protobuf has had decent support for self-describing messages (very similar to avro) as well as reflection

https://github.com/protocolbuffers/protobuf/blob/main/src/go...

Xgooglers trying to make do on the cheap will just create a Union of all their messages and include the message def in a self-describing message pattern. Super-sensitive network I/O can elide the message def (empty buffer) and any for RecordIO clone well file compression takes care of the definition.

Definitely useful to be able to dig out old defs but protobuf maintainers have surprisingly added useful features so you don’t have to.

Bonus points tho for extracting the protobuf defs that e.g. Apple bakes into their binaries.

gRPC Gateway is a protoc plugin that reads gRPC service definitions and generates a reverse proxy server that translates a RESTful JSON API into gRPC.

To use more recent versions of protoc in future applications, you can download them from the Protobuf repository.

Use the Protobuf CLI protoc and the plugin protoc-gen-tonic.

> didn’t find any standard for separating protobuf messages

The fact that protobufs are not self-delimiting is an endless source of frustration, but I know of 2 standards:

- SerializeDelimited* is part of the protobuf library: https://github.com/protocolbuffers/protobuf/blob/main/src/go...

- Riegeli is "a file format for storing a sequence of string records, typically serialized protocol buffers. It supports dense compression, fast decoding, seeking, detection and optional skipping of data corruption, filtering of proto message fields for even faster decoding, and parallel encoding": https://github.com/google/riegeli

It looks like it is in fact universal. Just glancing at the code here, it looks like the tool searches any arbitrary file for bytes that look like encoded protobuf descriptors, specifically looking for bytes that are plausibly the beginning of a FileDescriptorProto message defined here:

https://github.com/protocolbuffers/protobuf/blob/main/src/go...

This takes advantage of the fact that such descriptors are commonly compiled into programs that use protobuf. The descriptors are usually embedded as constant byte arrays. That said, not all protobuf implementations embed the descriptors and those that do often have an option to inhibit such embedding (at the expense of losing some dynamic introspection features).

Not much. You can check the source code in https://github.com/protocolbuffers/protobuf. For example, for serializing a boolean in C#: https://github.com/protocolbuffers/protobuf/blob/main/csharp/src/Google.Protobuf/WritingPrimitives.cs#L165. Strings and objects are a bit more complicated, but it is all about turning the data into its byte representation.

One of the key feature of gRPC is protobuf .proto file(nothing but just a contract for me between two communicator code components) This file and protobuff compiler is so mature, then it generates a direct client implementation using protoccompiler. ref