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| 1 | +/* |
| 2 | +Copyright © 2025 NAME HERE <EMAIL ADDRESS> |
| 3 | +*/ |
| 4 | +package cmd |
| 5 | + |
| 6 | +import ( |
| 7 | + "database/sql" |
| 8 | + "fmt" |
| 9 | + "log" |
| 10 | + "time" |
| 11 | + |
| 12 | + _ "github.com/go-sql-driver/mysql" |
| 13 | + |
| 14 | + "github.com/spf13/cobra" |
| 15 | +) |
| 16 | + |
| 17 | +// sqlCmd represents the sql command |
| 18 | +var sqlCmd = &cobra.Command{ |
| 19 | + Use: "sql", |
| 20 | + Short: "Wait for SQL connection", |
| 21 | + Long: `Wait for SQL connection until available |
| 22 | + |
| 23 | +Simple example: |
| 24 | + waitfor sql -u root -p mysecretpassword -s mariadb.mydatabase.cluster.local -d mydb |
| 25 | +
|
| 26 | +Example, if you have a non-standard port, set it with -P, default is 3306: |
| 27 | + waitfor sql -u root -p mysecretpassword -s mariadb.mydatabase.cluster.local -P 3307 -d mydb |
| 28 | +`, |
| 29 | + Run: func(cmd *cobra.Command, args []string) { |
| 30 | + |
| 31 | + user, _ := cmd.Flags().GetString("user") |
| 32 | + password, _ := cmd.Flags().GetString("password") |
| 33 | + server, _ := cmd.Flags().GetString("server") |
| 34 | + port, _ := cmd.Flags().GetString("port") |
| 35 | + database, _ := cmd.Flags().GetString("database") |
| 36 | + |
| 37 | + // check if required flags are set |
| 38 | + if user == "" || password == "" || server == "" || database == "" { |
| 39 | + log.Fatalf("Error: user, password, server and database are required") |
| 40 | + } |
| 41 | + |
| 42 | + // build dsn |
| 43 | + dsn := user + ":" + password + "@tcp(" + server + ":" + port + ")/" + database |
| 44 | + |
| 45 | + // Try to connect with db |
| 46 | + db, err := waitForDB(dsn, 10, time.Second*time.Duration(timer)) |
| 47 | + if err != nil { |
| 48 | + log.Fatalf("DB connection failed: %v", err) |
| 49 | + } |
| 50 | + defer db.Close() |
| 51 | + |
| 52 | + log.Println("Connection established!") |
| 53 | + }, |
| 54 | +} |
| 55 | + |
| 56 | +func init() { |
| 57 | + rootCmd.AddCommand(sqlCmd) |
| 58 | + sqlCmd.Flags().StringP("user", "u", "", "Database user") |
| 59 | + sqlCmd.Flags().StringP("password", "p", "", "Database password") |
| 60 | + sqlCmd.Flags().StringP("server", "s", "", "Database server") |
| 61 | + sqlCmd.Flags().StringP("port", "P", "3306", "Database port") |
| 62 | + sqlCmd.Flags().StringP("database", "d", "", "Database name") |
| 63 | +} |
| 64 | + |
| 65 | +func waitForDB(dsn string, retries int, delay time.Duration) (*sql.DB, error) { |
| 66 | + var db *sql.DB |
| 67 | + var err error |
| 68 | + |
| 69 | + for i := 0; i < retries; i++ { |
| 70 | + // Open does not establish a connection immediately, it just prepares the handle |
| 71 | + db, err = sql.Open("mysql", dsn) |
| 72 | + if err != nil { |
| 73 | + log.Printf("Error opening DB handle: %v", err) |
| 74 | + } else { |
| 75 | + // Ping actually checks if the DB is reachable |
| 76 | + err = db.Ping() |
| 77 | + if err == nil { |
| 78 | + return db, nil // success |
| 79 | + } |
| 80 | + log.Printf("DB not ready yet: %v", err) |
| 81 | + } |
| 82 | + |
| 83 | + // Wait before trying again |
| 84 | + time.Sleep(delay) |
| 85 | + } |
| 86 | + |
| 87 | + return nil, fmt.Errorf("could not connect after %d retries: %w", retries, err) |
| 88 | +} |
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