ruby - 合并特定值的两个哈希值

Question

我正在检查哈希值是否为 hash_volumes下面有一个键，其 instance_id与哈希 hash_instance 的键匹配.

hash_volumes = {
  :"vol-d16d12b8" => {
        :instance_id => "i-4e4ba679",
    },
}
hash_instance = {
  :"i-4e4ba679" => {
        :arch => "x86_64",
    },
}

如果是，那么我需要将它合并到 hash_instance .我发现 vol-d16d12b8与实例 i-4e4ba679 匹配因此我想将它与 hash_instance 合并这样最后的hash_instance将如下所示:

hash_instance = {
  :"i-4e4ba679" => {
        :arch => "x86_64",
        :volume => "vol-d16d12b8"  # this is new entry to `hash_instance`
    },
}

如上所述，我无法合并这两个哈希值。我怀疑我的if陈述是错误的。请看下面我的代码:

hash_volumes.each_key do |x|
  hash_instance.each_key do |y|
    if hash_volumes[x][:instance_id] == y  ## I think this line is the problem
      hash_instance[y][:volume] = x
    end
  end
end

hash_instance

输出:

{
    :"i-4e4ba679" => {
        :arch => "x86_64"
    }
}

上面的代码给出了hash_instance不添加 volume给它。我试过如下，但没有成功:

if hash_volumes[x][:instance_id] == "#{y}"
# => this if statement gives me syntax error

.....

if hash_volumes[x][:instance_id] =~ /"#{y}"/
# => this if statement does not make any changes to above output.

Answer 1

hash_volumes = {
  :"vol-d16d12b8" => {
        :instance_id => "i-4e4ba679",
    },
}

hash_instance = {
  :"i-4e4ba679" => {
        :arch => "x86_64",
    },
}

hash_volumes.each do |key, val|
  id = val[:instance_id]  #returns nil if the there is no :instance_id key

  if id 
    id_as_sym = id.to_sym

    if hash_instance.has_key? id_as_sym
      hash_instance[id_as_sym][:volume] = id
    end
  end
end


--output:--
{:"i-4e4ba679"=>{:arch=>"x86_64", :volume=>"i-4e4ba679"}}