替换Ruby中的YAML占位符

database:
  host: localhost
  port: 5432
  name: mydb
  user: ${DB_USER}
  password: ${DB_PASSWORD}

require 'yaml'

# 读取YAML文件
config = YAML.load_file('config.yaml')

# 定义占位符的值
placeholders = {
  '${DB_USER}' => 'admin',
  '${DB_PASSWORD}' => 'secret'
}

# 替换占位符
def replace_placeholders(hash, placeholders)
  hash.each do |key, value|
    if value.is_a?(String)
      placeholders.each do |placeholder, replacement|
        value.gsub!(placeholder, replacement)
      end
    elsif value.is_a?(Hash)
      replace_placeholders(value, placeholders)
    elsif value.is_a?(Array)
      value.each do |item|
        replace_placeholders(item, placeholders) if item.is_a?(Hash)
      end
    end
  end
end

replace_placeholders(config, placeholders)

# 输出替换后的配置
puts config.to_yaml