Remote configs

[orsinium]

Allow -rules option to be a remote URL. This makes ruleguard suitable to be used as a zero-configuration linter.

[x] Tests included. They check a small file with a local and remote copy of rules.go. Later, this file should be duplicated to make it possible to test new checks that weren't introduced in the master branch yet.
[x] README updated.

Minor changes:

1. Remove redundant if flagRules == "". The if body statement is unreachable.
2. Parse source code of rules.go right from the stream without reading it from the stream and then converting it into a stream again. It makes file reading a bit faster and memory-friendly.
3. Provide a short list of ready to use open-source rules.

[cristaloleg]

Thanks for the PR. I left few comments. By the way, the idea of the remote configs(rules) was sliiiiightly another, however fetching them via http should work too.

[cristaloleg]

why?

[orsinium]

My linter told me to do so. Namely, it is MD026 check. My motivation is that this is not an FAQ section, so you should answer questions, not to ask them. Also, Betteridge's law of headlines is a bit related as an example of why you should avoid question mark in headlines.

And as the last piece of motivation let's use crowd intelligence:

• https://github.com/search?q=%22How+it+works%22 (2 323 matches)
• https://github.com/search?q=%22How+does+it+work%22 (103 matches)

[cristaloleg]

lol, interesting

[cristaloleg]

Can we reuse another rules and not create new?

[orsinium]

What do you mean? This file exists because there are no tests for the root rules.go yet. However, it's good to test them.

[cristaloleg]

what was the point to change this part of the README? 👀

[orsinium]

It was not changed but rearranged. The text remains the same, git is bad at showing moved things. The motivation is to simplify the quick start.

Before:

• Quick start
  • create example code
  • create example rules
  • run ruleguard using the created rules file

Now:

• Quick start
  • create example code
  • run ruleguard using remote rules
• Using custom rules
  • create example rules
  • run ruleguard using local rules

[orsinium]

By the way, the idea of the remote configs(rules) was sliiiiightly another

Do you mean distributing plugins as go packages? Yes, @quasilyte told me about it a bit, this is another good idea and it would be cool to have it eventually implemented. However, this network-based implementation has the advantage of zero-configuration allowing a faster start and easier reusing of rules between different projects. This is how shared configs are implemented in flakehell, for instance.

[cristaloleg]

I'm skeptical of raw http configs.

[orsinium]

💔

[orsinium]

In a long run, it's always better to keep all the checks in your environment, sure. However, remote configs support opens a door for a faster start in both using ruleguard as a linter and distributing your own rules.

Also, it solves the licensing question. Since go mod has no separation between "prod" and "dev" environments, everything in your go.sum considered your project dependencies. And for project dependencies, you can have license constraints, especially when it is about a proprietary product. So, if rules are distributed under GPL 3.0 to limit their usage in a proprietary service, it could cause issues if using them as a package in you go.mod for purpose of using on dev environment only. This PR implements another approach, that more likely can be interpreted as dynamic linking. And as for dynamic linking, we do it explicitly only on a specified environment, keeping the project dependencies free from questionable licenses.

[cristaloleg]

remote configs support opens a door for a faster start

via DSL it will be almost the same, but instead of a url, there will be an import.

Regarding go.mod and licensing it's an open question. That's how ecosystem is built. I'm not 100% sure what is the proper answer. But merging http configs without previous discussion is kinda risky. Adding feature and than dropping it is a not proper way.

[orsinium]

All review comments are addressed.

[orsinium]

Feel free to re-open if you change your mind