discourse/app/models/global_setting.rb

# frozen_string_literal: true

class GlobalSetting
  def self.register(key, default)
    define_singleton_method(key) { provider.lookup(key, default) }
  end

  VALID_SECRET_KEY ||= /\A[0-9a-f]{128}\z/
  # this is named SECRET_TOKEN as opposed to SECRET_KEY_BASE
  # for legacy reasons
  REDIS_SECRET_KEY ||= "SECRET_TOKEN"

  REDIS_VALIDATE_SECONDS ||= 30

  # In Rails secret_key_base is used to encrypt the cookie store
  # the cookie store contains session data
  # Discourse also uses this secret key to digest user auth tokens
  # This method will
  # - use existing token if already set in ENV or discourse.conf
  # - generate a token on the fly if needed and cache in redis
  # - enforce rules about token format falling back to redis if needed
  def self.safe_secret_key_base
    if @safe_secret_key_base && @token_in_redis &&
         (@token_last_validated + REDIS_VALIDATE_SECONDS) < Time.now
      @token_last_validated = Time.now
      token = Discourse.redis.without_namespace.get(REDIS_SECRET_KEY)
      Discourse.redis.without_namespace.set(REDIS_SECRET_KEY, @safe_secret_key_base) if token.nil?
    end

    @safe_secret_key_base ||=
      begin
        token = secret_key_base
        if token.blank? || token !~ VALID_SECRET_KEY
          @token_in_redis = true
          @token_last_validated = Time.now

          token = Discourse.redis.without_namespace.get(REDIS_SECRET_KEY)
          unless token && token =~ VALID_SECRET_KEY
            token = SecureRandom.hex(64)
            Discourse.redis.without_namespace.set(REDIS_SECRET_KEY, token)
          end
        end
        if !secret_key_base.blank? && token != secret_key_base
          STDERR.puts "WARNING: DISCOURSE_SECRET_KEY_BASE is invalid, it was re-generated"
        end
        token
      end
  rescue Redis::CommandError => e
    @safe_secret_key_base = SecureRandom.hex(64) if e.message =~ /READONLY/
  end

  def self.load_defaults
    default_provider =
      FileProvider.from(File.expand_path("../../../config/discourse_defaults.conf", __FILE__))
    default_provider
      .keys
      .concat(@provider.keys)
      .uniq
      .each do |key|
        default = default_provider.lookup(key, nil)

        instance_variable_set("@#{key}_cache", nil)

        define_singleton_method(key) do
          val = instance_variable_get("@#{key}_cache")
          if val.nil?
            val = provider.lookup(key, default)
            val = :missing if val.nil?
            instance_variable_set("@#{key}_cache", val)
          end
          val == :missing ? nil : val
        end
      end
  end

  def self.skip_db=(v)
    @skip_db = v
  end

  def self.skip_db?
    @skip_db
  end

  def self.skip_redis=(v)
    @skip_redis = v
  end

  def self.skip_redis?
    @skip_redis
  end

  def self.use_s3?
    (
      @use_s3 ||=
        begin
          if s3_bucket && s3_region &&
               (s3_use_iam_profile || (s3_access_key_id && s3_secret_access_key))
            :true
          else
            :false
          end
        end
    ) == :true
  end

  def self.s3_bucket_name
    @s3_bucket_name ||= s3_bucket.downcase.split("/")[0]
  end

  # for testing
  def self.reset_s3_cache!
    @use_s3 = nil
  end

  def self.cdn_hostnames
    hostnames = []
    hostnames << URI.parse(cdn_url).host if cdn_url.present?
    hostnames << cdn_origin_hostname if cdn_origin_hostname.present?
    hostnames
  end

  def self.database_config
    hash = { "adapter" => "postgresql" }

    %w[
      pool
      connect_timeout
      socket
      host
      backup_host
      port
      backup_port
      username
      password
      replica_host
      replica_port
    ].each do |s|
      if val = self.public_send("db_#{s}")
        hash[s] = val
      end
    end

    hostnames = [hostname]
    hostnames << backup_hostname if backup_hostname.present?

    hostnames << URI.parse(cdn_url).host if cdn_url.present?
    hostnames << cdn_origin_hostname if cdn_origin_hostname.present?

    hash["host_names"] = hostnames
    hash["database"] = db_name
    hash["prepared_statements"] = !!self.db_prepared_statements
    hash["idle_timeout"] = connection_reaper_age if connection_reaper_age.present?
    hash["reaping_frequency"] = connection_reaper_interval if connection_reaper_interval.present?
    hash["advisory_locks"] = !!self.db_advisory_locks

    db_variables = provider.keys.filter { |k| k.to_s.starts_with? "db_variables_" }
    if db_variables.length > 0
      hash["variables"] = {}
      db_variables.each do |k|
        hash["variables"][k.slice(("db_variables_".length)..)] = self.public_send(k)
      end
    end

    { "production" => hash }
  end

  # For testing purposes
  def self.reset_redis_config!
    @config = nil
    @message_bus_config = nil
  end

  def self.get_redis_replica_host
    return redis_replica_host if redis_replica_host.present?
    redis_slave_host if respond_to?(:redis_slave_host) && redis_slave_host.present?
  end

  def self.get_redis_replica_port
    return redis_replica_port if redis_replica_port.present?
    redis_slave_port if respond_to?(:redis_slave_port) && redis_slave_port.present?
  end

  def self.get_message_bus_redis_replica_host
    return message_bus_redis_replica_host if message_bus_redis_replica_host.present?
    if respond_to?(:message_bus_redis_slave_host) && message_bus_redis_slave_host.present?
      message_bus_redis_slave_host
    end
  end

  def self.get_message_bus_redis_replica_port
    return message_bus_redis_replica_port if message_bus_redis_replica_port.present?
    if respond_to?(:message_bus_redis_slave_port) && message_bus_redis_slave_port.present?
      message_bus_redis_slave_port
    end
  end

  def self.redis_config
    @config ||=
      begin
        c = {}
        c[:host] = redis_host if redis_host
        c[:port] = redis_port if redis_port

        if get_redis_replica_host && get_redis_replica_port && defined?(RailsFailover)
          c[:replica_host] = get_redis_replica_host
          c[:replica_port] = get_redis_replica_port
          c[:connector] = RailsFailover::Redis::Connector
        end

        c[:password] = redis_password if redis_password.present?
        c[:db] = redis_db if redis_db != 0
        c[:db] = 1 if Rails.env == "test"
        c[:id] = nil if redis_skip_client_commands
        c[:ssl] = true if redis_use_ssl

        c.freeze
      end
  end

  def self.message_bus_redis_config
    return redis_config unless message_bus_redis_enabled
    @message_bus_config ||=
      begin
        c = {}
        c[:host] = message_bus_redis_host if message_bus_redis_host
        c[:port] = message_bus_redis_port if message_bus_redis_port

        if get_message_bus_redis_replica_host && get_message_bus_redis_replica_port
          c[:replica_host] = get_message_bus_redis_replica_host
          c[:replica_port] = get_message_bus_redis_replica_port
          c[:connector] = RailsFailover::Redis::Connector
        end

        c[:password] = message_bus_redis_password if message_bus_redis_password.present?
        c[:db] = message_bus_redis_db if message_bus_redis_db != 0
        c[:db] = 1 if Rails.env == "test"
        c[:id] = nil if message_bus_redis_skip_client_commands
        c[:ssl] = true if redis_use_ssl

        c.freeze
      end
  end

  def self.add_default(name, default)
    define_singleton_method(name) { default } unless self.respond_to? name
  end

  class BaseProvider
    def self.coerce(setting)
      return setting == "true" if setting == "true" || setting == "false"
      return $1.to_i if setting.to_s.strip =~ /\A([0-9]+)\z/
      setting
    end

    def resolve(current, default)
      BaseProvider.coerce(
        if current.present?
          current
        else
          default.present? ? default : nil
        end,
      )
    end
  end

  class FileProvider < BaseProvider
    attr_reader :data
    def self.from(file)
      parse(file) if File.exist?(file)
    end

    def initialize(file)
      @file = file
      @data = {}
    end

    def read
      ERB
        .new(File.read(@file))
        .result()
        .split("\n")
        .each do |line|
          if line =~ /\A\s*([a-z_]+[a-z0-9_]*)\s*=\s*(\"([^\"]*)\"|\'([^\']*)\'|[^#]*)/
            @data[$1.strip.to_sym] = ($4 || $3 || $2).strip
          end
        end
    end

    def lookup(key, default)
      var = @data[key]
      resolve(var, var.nil? ? default : "")
    end

    def keys
      @data.keys
    end

    def self.parse(file)
      provider = self.new(file)
      provider.read
      provider
    end

    private_class_method :parse
  end

  class EnvProvider < BaseProvider
    def lookup(key, default)
      var = ENV["DISCOURSE_" + key.to_s.upcase]
      resolve(var, var.nil? ? default : nil)
    end

    def keys
      ENV.keys.select { |k| k =~ /\ADISCOURSE_/ }.map { |k| k[10..-1].downcase.to_sym }
    end
  end

  class BlankProvider < BaseProvider
    def lookup(key, default)
      if key == :redis_port
        return ENV["DISCOURSE_REDIS_PORT"] if ENV["DISCOURSE_REDIS_PORT"]
      end
      default
    end

    def keys
      []
    end
  end

  class << self
    attr_accessor :provider
  end

  def self.configure!
    if Rails.env == "test"
      @provider = BlankProvider.new
    else
      @provider =
        FileProvider.from(File.expand_path("../../../config/discourse.conf", __FILE__)) ||
          EnvProvider.new
    end
  end

  def self.load_plugins?
    if ENV["LOAD_PLUGINS"] == "1"
      true
    elsif ENV["LOAD_PLUGINS"] == "0"
      false
    elsif Rails.env.test?
      false
    else
      true
    end
  end
end