【Cloud SQL】GolangでDBインスタンスの開始停止をDiscordで通知する

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// Package mypkg contains a Function to request to Discord Webhooks.
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package mypkg
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import (
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  "bytes"
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  "encoding/json"
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  "errors"
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  "fmt"
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  "net/http"
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)
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// Payload represents the payload structure for Discord notification.
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type Payload struct {
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  Username string      `json:"username"`
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  Content  string      `json:"content"`
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  Embeds   interface{} `json:"embeds,omitempty"`
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  TTS      bool        `json:"tts"`
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}
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// Embed represents a single embed structure.
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type Embed struct {
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  Title     string `json:"title"`
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  Color     int    `json:"color"`
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  URL       string `json:"url"`
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  Footer    Footer `json:"footer"`
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  Timestamp string `json:"timestamp,omitempty"`
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}
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// Footer represents the footer for an embed.
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type Footer struct {
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  Text    string `json:"text"`
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  IconURL string `json:"icon_url"`
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}
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// CreatePayloadOfDiscordNotification creates a payload for Discord webhook notification.
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func CreatePayloadOfDiscordNotification(botName, content string, embeds []Embed, isTTS bool) (Payload, error) {
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  if len(botName) > 2000 {
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    return Payload{}, errors.New("'botName' must be less than or equal to 2000 characters")
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  }
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  if len(content) > 2000 {
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    return Payload{}, errors.New("'content' must be less than or equal to 2000 characters")
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  }
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  if len(embeds) > 10 {
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    return Payload{}, errors.New("length of 'embeds' must be less than or equal to 10")
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  }
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  return Payload{
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    Username: botName,
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    Content:  content,
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    Embeds:   embeds,
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    TTS:      isTTS,
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  }, nil
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}
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// CreateEmbedsToNotifyCloudSql creates embeds for notification about DB booting.
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func CreateEmbedsToNotifyCloudSql(textToTransit, urlToTransit, iconURL string) []Embed {
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  return []Embed{
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    {
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      Title: textToTransit,
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      Color: 4569935,
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      URL:   urlToTransit,
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      Footer: Footer{
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        Text:    "GoogleCloudSQL",
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        IconURL: iconURL,
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      },
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    },
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  }
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}
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// NotifyToDiscord sends a notification to a Discord webhook.
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func NotifyToDiscord(webhookURL string, payload Payload) (string, error) {
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  payloadBytes, err := json.Marshal(payload)
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  if err != nil {
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    return "", fmt.Errorf("failed to marshal payload: %v", err)
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  }
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  req, err := http.NewRequest("POST", webhookURL, bytes.NewBuffer(payloadBytes))
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  if err != nil {
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    return "", fmt.Errorf("failed to create HTTP request: %v", err)
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  }
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  req.Header.Set("Content-Type", "application/json")
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  client := &http.Client{}
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  resp, err := client.Do(req)
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  if err != nil {
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    return "", fmt.Errorf("failed to send HTTP request: %v", err)
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  }
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  defer resp.Body.Close()
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  if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNoContent {
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    return "", fmt.Errorf("unexpected HTTP response: %s", resp.Status)
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  }
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  return "Notification sent successfully", nil
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}
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// NotifyDbBooting sends a notification about Google Cloud SQL.
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func NotifyDbBooting(content, textToTransit, urlOfConsoleForDbInstance, webhookUrl, iconUrl string) (map[string]string, error) {
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  botName := "CloudSQLあゆ"
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  embeds := CreateEmbedsToNotifyCloudSql(textToTransit, urlOfConsoleForDbInstance, iconUrl)
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  payload, err := CreatePayloadOfDiscordNotification(botName, content, embeds, false)
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  if err != nil {
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    return nil, err
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  }
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  response, err := NotifyToDiscord(webhookUrl, payload)
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  if err != nil {
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    return nil, err
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  }
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  fmt.Println(response)
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  return map[string]string{
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    "destinations":    "discord",
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    "discord_content": content,
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  }, nil
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}

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func main() {
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  content := "データベース起動！"
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  textToTransit := "DBを起動したよ！"
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  urlOfConsoleForDbInstance, ok := os.LookupEnv("MY_DB_INSTANCE_URL"); if !ok {
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    fmt.Printf("Error: %v\n", ok)
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  }
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  webhookURL, ok := os.LookupEnv("MY_DISCORD_WEBHOOK_URL"); if !ok {
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    fmt.Printf("Error: %v\n", ok)
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  }
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  iconURL, ok := os.LookupEnv("CLOUD_SQL_ICON_URL"); if !ok {
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    fmt.Printf("Error: %v\n", ok)
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  }
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  result, err := mypkg.NotifyDbBooting(content, textToTransit, urlOfConsoleForDbInstance, webhookURL, iconURL)
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  if err != nil {
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    fmt.Printf("Error: %v\n", err)
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  } else {
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    fmt.Printf("Notification result: %+v\n", result)
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  }
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}