prober: remove unused notification code

Signed-off-by: Anton Tolchanov <anton@tailscale.com>

prober/notification.go

@@ -1,139 +0,0 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-package prober
-
-import (
-	"bytes"
-	"encoding/json"
-	"errors"
-	"expvar"
-	"fmt"
-	"io"
-	"net/http"
-	"os"
-	"strings"
-	"time"
-
-	"github.com/google/uuid"
-	"tailscale.com/util/httpm"
-)
-
-var (
-	alertGenerated   = expvar.NewInt("alert_generated")
-	alertFailed      = expvar.NewInt("alert_failed")
-	warningGenerated = expvar.NewInt("warning_generated")
-	warningFailed    = expvar.NewInt("warning_failed")
-)
-
-// SendAlert sends an alert to the incident response system, to
-// page a human responder immediately.
-// summary should be short and state the nature of the emergency.
-// details can be longer, up to 29 KBytes.
-func SendAlert(summary, details string) error {
-	type squadcastAlert struct {
-		Message     string            `json:"message"`
-		Description string            `json:"description"`
-		Tags        map[string]string `json:"tags,omitempty"`
-		Status      string            `json:"status"`
-		EventId     string            `json:"event_id"`
-	}
-
-	sqa := squadcastAlert{
-		Message:     summary,
-		Description: details,
-		Tags:        map[string]string{"severity": "critical"},
-		Status:      "trigger",
-		EventId:     uuid.New().String(),
-	}
-
-	sqBody, err := json.Marshal(sqa)
-	if err != nil {
-		alertFailed.Add(1)
-		return fmt.Errorf("encoding alert payload: %w", err)
-	}
-
-	webhookUrl := os.Getenv("SQUADCAST_WEBHOOK")
-	if webhookUrl == "" {
-		warningFailed.Add(1)
-		return errors.New("no SQUADCAST_WEBHOOK configured")
-	}
-
-	req, err := http.NewRequest(httpm.POST, webhookUrl, bytes.NewBuffer(sqBody))
-	if err != nil {
-		alertFailed.Add(1)
-		return err
-	}
-
-	req.Header.Set("Content-Type", "application/json")
-
-	client := &http.Client{Timeout: 10 * time.Second}
-	resp, err := client.Do(req)
-	if err != nil {
-		alertFailed.Add(1)
-		return err
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != 200 {
-		alertFailed.Add(1)
-		return errors.New(resp.Status)
-	}
-
-	body, _ := io.ReadAll(resp.Body)
-	if string(body) != "ok" {
-		alertFailed.Add(1)
-		return errors.New("non-ok response returned from Squadcast")
-	}
-
-	alertGenerated.Add(1)
-	return nil
-}
-
-// SendWarning will post a message to Slack.
-// details should be a description of the issue.
-func SendWarning(details string) error {
-	webhookUrl := os.Getenv("SLACK_WEBHOOK")
-	if webhookUrl == "" {
-		warningFailed.Add(1)
-		return errors.New("no SLACK_WEBHOOK configured")
-	}
-
-	type slackRequestBody struct {
-		Text string `json:"text"`
-	}
-
-	slackBody, err := json.Marshal(slackRequestBody{Text: details})
-	if err != nil {
-		warningFailed.Add(1)
-		return err
-	}
-
-	req, err := http.NewRequest("POST", webhookUrl, bytes.NewReader(slackBody))
-	if err != nil {
-		warningFailed.Add(1)
-		return err
-	}
-	req.Header.Set("Content-Type", "application/json")
-
-	client := &http.Client{Timeout: 10 * time.Second}
-	resp, err := client.Do(req)
-	if err != nil {
-		warningFailed.Add(1)
-		return err
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode != http.StatusOK {
-		warningFailed.Add(1)
-		return errors.New(resp.Status)
-	}
-
-	body, _ := io.ReadAll(resp.Body)
-	if s := strings.TrimSpace(string(body)); s != "ok" {
-		warningFailed.Add(1)
-		return errors.New("non-ok response returned from Slack")
-	}
-	warningGenerated.Add(1)
-	return nil
-}