package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"log"
	"os/exec"
	"strings"
	"sync"
)

type command struct {
	node   string
	port   int
	url    string
	health string
}

type dcosJSON struct {
	Name     string `json:"name"`
	Statuses []struct {
		ContainerStatus struct {
			ContainerID struct {
				Value string `json:"value"`
			} `json:"container_id"`
			NetworkInfos []struct {
				IPAddresses []struct {
					IPAddress string `json:"ip_address"`
				} `json:"ip_addresses"`
			} `json:"network_infos"`
		} `json:"container_status"`
		State     string  `json:"state"`
		Timestamp float64 `json:"timestamp"`
	} `json:"statuses"`
}

type apiserverIPs struct {
	name string
	ip   string
}

func getAPIServerIPs() []apiserverIPs {
	cmd := exec.Command("dcos", "task", "--json")
	var out bytes.Buffer
	cmd.Stdout = &out
	err := cmd.Run()
	if err != nil {
		log.Fatal(err)
	}

	d := []dcosJSON{}
	if err := json.Unmarshal([]byte(out.String()), &d); err != nil {
		panic(err)
	}
	ips := []apiserverIPs{}
	for _, i := range d {
		if strings.Contains(i.Name, "apiserver") {
			ips = append(
				ips,
				apiserverIPs{
					name: i.Name,
					ip:   i.Statuses[0].ContainerStatus.NetworkInfos[0].IPAddresses[0].IPAddress,
				},
			)
		}
	}
	return ips
}

func addAPIServer(n string, ips []apiserverIPs) string {
	for _, i := range ips {
		if strings.Contains(i.name, n) {
			return i.ip
		}
	}
	return ""
}

func main() {
	var wg sync.WaitGroup
	ips := getAPIServerIPs()
	hosts := []command{
		command{node: "kube-controller-manager-0-node", port: 10252, url: "localhost", health: "healthz"},
		command{node: "kube-controller-manager-1-node", port: 10252, url: "localhost", health: "healthz"},
		command{node: "kube-controller-manager-2-node", port: 10252, url: "localhost", health: "healthz"},
		command{node: "kube-scheduler-0-node", port: 10252, url: "localhost", health: "healthz"},
		command{node: "kube-scheduler-1-node", port: 10251, url: "localhost", health: "healthz"},
		command{node: "kube-scheduler-2-node", port: 10251, url: "localhost", health: "healthz"},
		command{node: "kube-apiserver-0-node", port: 9000, url: addAPIServer("0", ips), health: "healthz"},
		command{node: "kube-apiserver-1-node", port: 9000, url: addAPIServer("1", ips), health: "healthz"},
		command{node: "kube-apiserver-2-node", port: 9000, url: addAPIServer("2", ips), health: "healthz"},
		command{node: "etcd-0-node", port: 2379, url: "localhost", health: "health"},
		command{node: "etcd-1-node", port: 2379, url: "localhost", health: "health"},
		command{node: "etcd-2-node", port: 2379, url: "localhost", health: "health"},
	}

	for _, n := range hosts {
		wg.Add(1)
		go func(c command) {
			defer wg.Done()
			cmd := exec.Command(
				"dcos",
				"task",
				"exec",
				c.node,
				"/usr/bin/curl",
				"-sSf",
				fmt.Sprintf("%s:%d/%s", c.url, c.port, c.health),
			)
			var out bytes.Buffer
			cmd.Stdout = &out
			err := cmd.Run()
			if err != nil {
				log.Fatal(err)
			}
			fmt.Printf("%v: %q\n", c, out.String())
		}(n)
	}
	wg.Wait()
}