Sentinels: Accept options to connect to master

[jlledom]

I tried to use SentinelClient on my project and found I couldn't connect to Sentinels + TLS or ACL. The reason is there no way to provide connection options for the master, only for the sentinels. So sentinels can be protected with TLS and ACL and async-reds will connect to them, but after resolving master, SentinelClient will only connect to master if it is not protected by TLS nor ACL.

I wrote this script to test the changes:

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  #gem 'async-redis'
  gem 'async-redis', git: 'https://github.com/jlledom/async-redis', branch: 'jlledom-sentinels-tls-acl'
end

def main
  Async do
    sentinels = [{ host: 'localhost', port: 56380 },
                 { host: 'localhost', port: 56381 },
                 { host: 'localhost', port: 56382 }]

    ssl_params = {
      ca_file: '/path/to/ca-root-cert.pem',
    }
    ssl_context = OpenSSL::SSL::SSLContext.new.tap do |context|
      context.set_params(ssl_params)
    end

    database = '6'
    credentials = %w[username password]
    endpoint_options = {database:, credentials:, ssl_context: }.compact

    sentinel_credentials = %w[sentinel_username sentinel_password]
    master_name = 'redis-master'
    role = :master

    endpoints = sentinels.map do |sentinel|
      scheme = ssl_context ? 'rediss' : 'redis'
      host = sentinel[:host]
      port = sentinel[:port]
      sentinel_uri = URI::Generic.build(scheme:, host:, port:)
      Async::Redis::Endpoint.new(sentinel_uri, nil, credentials: sentinel_credentials, ssl_context:)
    end
    client = Async::Redis::SentinelClient.new(endpoints, master_name:, master_options: endpoint_options, role:)

    while true
      begin
        sleep 1
        result = client.ping 'test'
        puts result
      rescue StandardError => e
        puts e.message
        retry
      end
    end
  end
end

main

Types of Changes

• Bug fix.

Contribution

• I added tests for my changes.
• I tested my changes locally.
• I agree to the Developer's Certificate of Origin 1.1.

I didn't add tests because those must involve much more than just writing the tests. It would require creating a new docker compose file, new certificates, config files, etc.

[jlledom]

I removed the @protocol instance variable because, AFAIK, it is only used to connect to the master, and at this point we still don't know which one will be.

[jlledom]

I don't kinda like this, any ideas?

[jlledom]

I'm not sure what is this for. I hope I'm not breaking anything.

[jlledom]

Here we use the endpoint protocol to connect to the endpoint, I think this is more correct and removes the need for the instance variable.