context

Coming from languages like golang you might miss the equivalent of a context providing library to help support your cross functional requirements. This library adds the context right to the current Fiber. It handles immutable context variables using Fiber.current.with_values that can be accessed by Fiber.current[].

The heavy lifting is done by the stdlib Log::Metadata implementation.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     context:
       github: threez/context.cr

2. Run shards install

Usage

require "context"
require "http/server"
require "http/client"

class AuthHandler
  include HTTP::Handler

  def call(context)
    # take token from request and verify it
    Fiber.current.with_values token: "123" do
      call_next(context)
    end
  end
end

# lets assume that is a different internal micro service that wants to get the token...
client = HTTP::Client.new(URI.parse("https://example.com"))
client.before_request do |context|
  context.headers["Authorization"] = "Bearer #{Fiber.current[:token]}"
end

server = HTTP::Server.new([
  AuthHandler.new,
]) do |context|
  context.response.content_type = "text/plain"
  context.response.print "Hello world, got #{context.request.path}!"

  client.get("/secret/data")
end

puts "Listening on http://127.0.0.1:8080"
server.listen(8080)

Resources

• Forum Discussion

Contributing

1. Fork it (https://github.com/threez/context/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• threez - creator and maintainer