JQ:从jq中的JSON数组中删除空值

Question

但是，我仍然不知道如何从JSON数组类型的键中删除空值。如果所有值都为null或从JSON数组中删除null，则需要一个空键({})。在下面的示例中，我希望从工作负载JSON数组中过滤空值。请告诉我有什么解决办法。非常感谢。例如，我使用的是jq版本1.5，输入如下：

{
  "EC2 Instance Metadata": [
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-1",
      "EC2 Private IPv4 address": "1.2.3.4",
      "Workloads": [
        null
      ],
      "Application Pods": [
        "pod-1"
      ],
      "Application Containers": [
        "container"
      ],
      "Container Images": [
        "image/1.0"
      ]
    },
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-2",
      "EC2 Private IPv4 address": "1.2.3.44",
      "Workloads": [
        null
      ],
      "Application Pods": [
        "pod-2"
      ],
      "Application Containers": [
        "container-2"
      ],
      "Container Images": [
        "image/2.0"
      ]
    },
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-3",
      "EC2 Private IPv4 address": "1.23.3.44",
      "Workloads": [
        "workload-1",
        "workload-2",
        "workload-3",
        null,
        null,
        null,
        "workload-4"
      ],
      "Application Pods": [
        "pod-1",
        "pod-2"
      ],
      "Application Containers": [
        "cnt-1",
        "cnt-2"
      ],
      "Container Images": [
        "image-1",
        "image-2"
      ]
    }
  ]
}

我要这个输出:-

{
  "EC2 Instance Metadata": [
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-1",
      "EC2 Private IPv4 address": "1.2.3.4",
      "Workloads": [
        {}
      ],
      "Application Pods": [
        "pod-1"
      ],
      "Application Containers": [
        "container"
      ],
      "Container Images": [
        "image/1.0"
      ]
    },
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-2",
      "EC2 Private IPv4 address": "1.2.3.44",
      "Workloads": [
        {}
      ],
      "Application Pods": [
        "pod-2"
      ],
      "Application Containers": [
        "container-2"
      ],
      "Container Images": [
        "image/2.0"
      ]
    },
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-3",
      "EC2 Private IPv4 address": "1.23.3.44",
      "Workloads": [
        "workload-1",
        "workload-2",
        "workload-3",
        "workload-4"
      ],
      "Application Pods": [
        "pod-1",
        "pod-2"
      ],
      "Application Containers": [
        "cnt-1",
        "cnt-2"
      ],
      "Container Images": [
        "image-1",
        "image-2"
      ]
    }
  ]
}

尝试了几乎所有提到这里的提示，但都没有成功。

Answer 1

此递归(..)将包含(也) values (除null以外的任何内容)的arrays简化为只包含那些values，否则(只包含null)将其替换为[{}]。

jq '(.. | arrays) |= if any(values) then map(values) else [{}] end'

{
  "EC2 Instance Metadata": [
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-1",
      "EC2 Private IPv4 address": "1.2.3.4",
      "Workloads": [
        {}
      ],
      "Application Pods": [
        "pod-1"
      ],
      "Application Containers": [
        "container"
      ],
      "Container Images": [
        "image/1.0"
      ]
    },
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-2",
      "EC2 Private IPv4 address": "1.2.3.44",
      "Workloads": [
        {}
      ],
      "Application Pods": [
        "pod-2"
      ],
      "Application Containers": [
        "container-2"
      ],
      "Container Images": [
        "image/2.0"
      ]
    },
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-3",
      "EC2 Private IPv4 address": "1.23.3.44",
      "Workloads": [
        "workload-1",
        "workload-2",
        "workload-3",
        "workload-4"
      ],
      "Application Pods": [
        "pod-1",
        "pod-2"
      ],
      "Application Containers": [
        "cnt-1",
        "cnt-2"
      ],
      "Container Images": [
        "image-1",
        "image-2"
      ]
    }
  ]
}

演示

Answer 2

如果我们在Workload上循环，我们可以使用更新分配(|=)和if来：

1. 使用all(. == null)检查所有值是否为null，如果为null，则用[ {} ]替换
2. 否则，使用map(values)只保留非null的值。

."EC2 Instance Metadata"[].Workloads |= 
    if all(. == null) 
        then [ {} ] 
        else map(values)
    end

将提供以下输出，您可以将其用于试试看这个在线演示

{
  "EC2 Instance Metadata": [
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-1",
      "EC2 Private IPv4 address": "1.2.3.4",
      "Workloads": [
        {}
      ],
      "Application Pods": [
        "pod-1"
      ],
      "Application Containers": [
        "container"
      ],
      "Container Images": [
        "image/1.0"
      ]
    },
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-2",
      "EC2 Private IPv4 address": "1.2.3.44",
      "Workloads": [
        {}
      ],
      "Application Pods": [
        "pod-2"
      ],
      "Application Containers": [
        "container-2"
      ],
      "Container Images": [
        "image/2.0"
      ]
    },
    {
      "EC2 Private IPv4 DNS Name": "compute.internal-3",
      "EC2 Private IPv4 address": "1.23.3.44",
      "Workloads": [
        "workload-1",
        "workload-2",
        "workload-3",
        "workload-4"
      ],
      "Application Pods": [
        "pod-1",
        "pod-2"
      ],
      "Application Containers": [
        "cnt-1",
        "cnt-2"
      ],
      "Container Images": [
        "image-1",
        "image-2"
      ]
    }
  ]
}