如何查看在当前的ingress-controller中，有哪些backend?每个backend的endpoints是什么？

通过kubectl ingress-nginx命令，可以查看在ingress controller中，有哪些backends，每个backends的后端的endpoints信息和对应其他的参数设置

比如：

kubectl ingress-nginx backends -n ingress-nginx

[root@nccztsjb-node-23 data]# kubectl ingress-nginx backends -n ingress-nginx
[
  {
    "name": "default-nginx-deployment-80",
    "service": {
      "metadata": {
        "creationTimestamp": null
      },
      "spec": {
        "ports": [
          {
            "protocol": "TCP",
            "port": 80,
            "targetPort": 80
          }
        ],
        "selector": {
          "app": "nginx"
        },
        "clusterIP": "10.98.87.101",
        "clusterIPs": [
          "10.98.87.101"
        ],
        "type": "ClusterIP",
        "sessionAffinity": "ClientIP",
        "sessionAffinityConfig": {
          "clientIP": {
            "timeoutSeconds": 10800
          }
        },
        "ipFamilies": [
          "IPv4"
        ],
        "ipFamilyPolicy": "SingleStack",
        "internalTrafficPolicy": "Cluster"
      },
      "status": {
        "loadBalancer": {}
      }
    },
    "port": 80,
    "sslPassthrough": false,
    "endpoints": [
      {
        "address": "172.39.157.239",
        "port": "80"
      },
      {
        "address": "172.39.21.93",
        "port": "80"
      },
      {
        "address": "172.39.21.95",
        "port": "80"
      }
    ],
    "sessionAffinityConfig": {
      "name": "",
      "mode": "",
      "cookieSessionAffinity": {
        "name": ""
      }
    },
    "upstreamHashByConfig": {
      "upstream-hash-by-subset-size": 3
    },
    "noServer": false,
    "trafficShapingPolicy": {
      "weight": 0,
      "weightTotal": 0,
      "header": "",
      "headerValue": "",
      "headerPattern": "",
      "cookie": ""
    }
  },
  {
    "name": "upstream-default-backend",
    "port": 0,
    "sslPassthrough": false,
    "endpoints": [
      {
        "address": "127.0.0.1",
        "port": "8181"
      }
    ],
    "sessionAffinityConfig": {
      "name": "",
      "mode": "",
      "cookieSessionAffinity": {
        "name": ""
      }
    },
    "upstreamHashByConfig": {},
    "noServer": false,
    "trafficShapingPolicy": {
      "weight": 0,
      "weightTotal": 0,
      "header": "",
      "headerValue": "",
      "headerPattern": "",
      "cookie": ""
    }
  }
]
 

如果这个数据很多，想要查看到底有哪些的backends呢？

可以使用jq工具，可以将数据转换为json格式，然后选择出来某个字段

kubectl ingress-nginx backends -n ingress-nginx | jq ".[].name"

 

[root@nccztsjb-node-23 data]# kubectl ingress-nginx backends -n ingress-nginx | jq ".[].name"
"default-nginx-deployment-80"
"upstream-default-backend"
[root@nccztsjb-node-23 data]# 

jq工具，可以通过

yum install -y jq

来进行安装

这样呢，就可获取到了所有的backends的信息

然后，这个时候呢，就可以获取某个特定的backends的信息了，比如：

使用--backend参数

kubectl ingress-nginx backends -n ingress-nginx --backend default-nginx-deployment-80
 

[root@nccztsjb-node-23 data]# kubectl ingress-nginx backends -n ingress-nginx --backend default-nginx-deployment-80
{
  "endpoints": [
    {
      "address": "172.39.157.239",
      "port": "80"
    },
    {
      "address": "172.39.21.93",
      "port": "80"
    },
    {
      "address": "172.39.21.95",
      "port": "80"
    }
  ],
  "name": "default-nginx-deployment-80",
  "noServer": false,
  "port": 80,
  "service": {
    "metadata": {
      "creationTimestamp": null
    },
    "spec": {
      "clusterIP": "10.98.87.101",
      "clusterIPs": [
        "10.98.87.101"
      ],
      "internalTrafficPolicy": "Cluster",
      "ipFamilies": [
        "IPv4"
      ],
      "ipFamilyPolicy": "SingleStack",
      "ports": [
        {
          "port": 80,
          "protocol": "TCP",
          "targetPort": 80
        }
      ],
      "selector": {
        "app": "nginx"
      },
      "sessionAffinity": "ClientIP",
      "sessionAffinityConfig": {
        "clientIP": {
          "timeoutSeconds": 10800
        }
      },
      "type": "ClusterIP"
    },
    "status": {
      "loadBalancer": {}
    }
  },
  "sessionAffinityConfig": {
    "cookieSessionAffinity": {
      "name": ""
    },
    "mode": "",
    "name": ""
  },
  "sslPassthrough": false,
  "trafficShapingPolicy": {
    "cookie": "",
    "header": "",
    "headerPattern": "",
    "headerValue": "",
    "weight": 0,
    "weightTotal": 0
  },
  "upstreamHashByConfig": {
    "upstream-hash-by-subset-size": 3
  }
}
 

还可以查看这个backend的endpoints

[root@nccztsjb-node-23 data]# kubectl ingress-nginx backends -n ingress-nginx --backend default-nginx-deployment-80 | jq ".endpoints"
[
  {
    "address": "172.39.157.239",
    "port": "80"
  },
  {
    "address": "172.39.21.93",
    "port": "80"
  },
  {
    "address": "172.39.21.95",
    "port": "80"
  }
]
[root@nccztsjb-node-23 data]#

这里面，主要是借助了jq这个工具，对输出进行格式化，对某个字段值的值进行选择。