ubuntu20.04如何使用cadvisor来使prometheus采集到docker容器中的gpu信息，以及gpu在宿主机中使用率的占比，请详细列出各个步骤需要的代码，并且创建一个grafana仪表盘的json文件来展示采集到的信息

好的，以下是详细的步骤和代码，以及grafana仪表盘的json文件：

步骤1：安装cadvisor和prometheus

# 安装cadvisor
sudo docker run \
  --volume=/:/rootfs:ro \
  --volume=/var/run:/var/run:rw \
  --volume=/sys:/sys:ro \
  --volume=/var/lib/docker/:/var/lib/docker:ro \
  --publish=8080:8080 \
  --detach=true \
  --name=cadvisor \
  google/cadvisor:latest

# 安装prometheus
wget https://github.com/prometheus/prometheus/releases/download/v2.23.0/prometheus-2.23.0.linux-amd64.tar.gz
tar xvfz prometheus-2.23.0.linux-amd64.tar.gz
cd prometheus-2.23.0.linux-amd64/

步骤2：配置prometheus.yml文件，将cadvisor添加为一个job

# 编辑prometheus.yml文件
vi prometheus.yml

# 添加以下内容
scrape_configs:
  - job_name: 'cadvisor'
    static_configs:
    - targets: ['localhost:8080']

步骤3：启动prometheus

./prometheus --config.file=prometheus.yml

步骤4：在grafana中添加prometheus数据源
- 点击“Configuration” -> “Data Sources” -> “Add data source”
- 选择“Prometheus”作为类型
- 在URL栏中输入“http://localhost:9090”(默认prometheus端口)
- 点击“Save & Test”

步骤5：创建grafana仪表盘
- 点击“Create” -> “Dashboard”
- 选择“Add Query” -> “Query” -> “Prometheus”
- 在query栏中输入以下内容来获取GPU的使用率：

rate(container_gpu_usage{name=~".+"}[1m])

- 在query栏中输入以下内容来获取GPU在宿主机中的使用率：

sum(node_gpu_utilisation)/count(node_gpu_utilisation)

- 在右上角选择“Graph”，并将查询结果添加到仪表盘中
- 点击“Save Dashboard”，并将其命名为“GPU Usage”

最后，以下是grafana仪表盘的json文件：

{
  "dashboard": {
    "id": null,
    "title": "GPU Usage",
    "timezone": "browser",
    "rows": [
      {
        "title": "GPU Usage",
        "height": "300px",
        "panels": [
          {
            "legend": {
              "show": true
            },
            "targets": [
              {
                "expr": "rate(container_gpu_usage{name=~\".+\"}[1m])",
                "format": "time_series",
                "interval": "",
                "intervalFactor": 1,
                "refId": "A"
              }
            ],
            "title": "GPU Usage",
            "type": "graph",
            "yaxes": [
              {
                "format": "percent",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxis": {
              "align": false,
              "alignLevel": null
            },
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 0,
              "y": 0
            }
          },
          {
            "legend": {
              "show": true
            },
            "targets": [
              {
                "expr": "sum(node_gpu_utilisation)/count(node_gpu_utilisation)",
                "format": "time_series",
                "interval": "",
                "intervalFactor": 1,
                "refId": "A"
              }
            ],
            "title": "GPU Usage in Host",
            "type": "graph",
            "yaxes": [
              {
                "format": "percent",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              },
              {
                "format": "short",
                "label": null,
                "logBase": 1,
                "max": null,
                "min": null,
                "show": true
              }
            ],
            "xaxis": {
              "buckets": null,
              "mode": "time",
              "name": null,
              "show": true,
              "values": []
            },
            "yaxis": {
              "align": false,
              "alignLevel": null
            },
            "gridPos": {
              "h": 8,
              "w": 12,
              "x": 0,
              "y": 8
            }
          }
        ]
      }
    ],
    "schemaVersion": 22,
    "version": 0
  },
  "folderId": null,
  "overwrite": false
}