Add support for updating tags on Alerts and Dashboards about go-wavefront HOT 1 OPEN

package main

import (
	"fmt"
	"github.com/spaceapegames/go-wavefront"
	"time"
)

func create(alertClient *wavefront.Alerts) (*wavefront.Alert, error) {
	a := &wavefront.Alert{
		Name: "test alert",
		Target: "[email protected]",
		Condition: "ts(proc.stat.cpu, dc=local) > 100",
		DisplayExpression: "ts(proc.stat.cpu, dc=local)",
		Minutes: 2,
		Tags: []string{"test", "go-wavefront"},
		Severity: "INFO",
	}

	err := alertClient.Create(a)
	if err != nil {
		return nil, err
	}

	return a, nil
}

func get(alertClient *wavefront.Alerts, id string) (*wavefront.Alert, error) {
	a := &wavefront.Alert{
		ID: &id,
	}

	err := alertClient.Get(a)
	if err != nil {
		return nil, err
	}

	return a, nil
}

func update(alertClient *wavefront.Alerts, alert *wavefront.Alert) error {
	err := alertClient.Update(alert)
	if err != nil {
		return err
	}

	return nil
}

func main() {
	config := &wavefront.Config{
		Address: "test.wavefront.com",
		Token: "xxx-xxx-xxx-xxx",
	}

	client, err := wavefront.NewClient(config)
	if err != nil {
		panic(err)
	}

	alerts := client.Alerts()

	// Begin by creating a new alert with 2 tags
	a, err := create(alerts)
	if err != nil {
		panic(err)
	}

	fmt.Printf("Created alert with id %s\n", *a.ID)

	if len(a.Tags) != 2 {
		panic(
			fmt.Sprintf("Expected 2 tags but found %d. Tags: %v.\n",
				len(a.Tags), a.Tags))
	}

	// Append a tag
	a.Tags = append(a.Tags, "appended-tag")

	err = update(alerts, a)
	if err != nil {
		panic(err)
	}

	fmt.Println("Updated alert")

	// Sleep for a little bit so WF can index the new alert
	// If we try to fetch too soon after creating, we can
	// get a 404
	fmt.Println("Waiting for 30s now...")
	time.Sleep(30 * time.Second)

	// fetch the alert again and check tags
	finalAlert, err := get(alerts, *a.ID)
	if err != nil {
		panic(err)
	}

	if len(finalAlert.Tags) != 3 {
		panic(
			fmt.Sprintf("Expected 3 tags but found %d. Tags: %v.\n",
				len(finalAlert.Tags), finalAlert.Tags))
	}

	fmt.Printf("Found tags: %v\n", finalAlert.Tags)
}