vendor/github.com/hashicorp/terraform/helper/acctest/random.go

   1 package acctest
   2
   3 import (
   4         "bufio"
   5         "bytes"
   6         crand "crypto/rand"
   7         "crypto/rsa"
   8         "crypto/x509"
   9         "encoding/pem"
  10         "fmt"
  11         "math/rand"
  12         "strings"
  13         "time"
  14
  15         "golang.org/x/crypto/ssh"
  16 )
  17
  18 // Helpers for generating random tidbits for use in identifiers to prevent
  19 // collisions in acceptance tests.
  20
  21 // RandInt generates a random integer
  22 func RandInt() int {
  23         reseed()
  24         return rand.New(rand.NewSource(time.Now().UnixNano())).Int()
  25 }
  26
  27 // RandomWithPrefix is used to generate a unique name with a prefix, for
  28 // randomizing names in acceptance tests
  29 func RandomWithPrefix(name string) string {
  30         reseed()
  31         return fmt.Sprintf("%s-%d", name, rand.New(rand.NewSource(time.Now().UnixNano())).Int())
  32 }
  33
  34 func RandIntRange(min int, max int) int {
  35         reseed()
  36         source := rand.New(rand.NewSource(time.Now().UnixNano()))
  37         rangeMax := max - min
  38
  39         return int(source.Int31n(int32(rangeMax)))
  40 }
  41
  42 // RandString generates a random alphanumeric string of the length specified
  43 func RandString(strlen int) string {
  44         return RandStringFromCharSet(strlen, CharSetAlphaNum)
  45 }
  46
  47 // RandStringFromCharSet generates a random string by selecting characters from
  48 // the charset provided
  49 func RandStringFromCharSet(strlen int, charSet string) string {
  50         reseed()
  51         result := make([]byte, strlen)
  52         for i := 0; i < strlen; i++ {
  53                 result[i] = charSet[rand.Intn(len(charSet))]
  54         }
  55         return string(result)
  56 }
  57
  58 // RandSSHKeyPair generates a public and private SSH key pair. The public key is
  59 // returned in OpenSSH format, and the private key is PEM encoded.
  60 func RandSSHKeyPair(comment string) (string, string, error) {
  61         privateKey, err := rsa.GenerateKey(crand.Reader, 1024)
  62         if err != nil {
  63                 return "", "", err
  64         }
  65
  66         var privateKeyBuffer bytes.Buffer
  67         privateKeyPEM := &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(privateKey)}
  68         if err := pem.Encode(bufio.NewWriter(&privateKeyBuffer), privateKeyPEM); err != nil {
  69                 return "", "", err
  70         }
  71
  72         publicKey, err := ssh.NewPublicKey(&privateKey.PublicKey)
  73         if err != nil {
  74                 return "", "", err
  75         }
  76         keyMaterial := strings.TrimSpace(string(ssh.MarshalAuthorizedKey(publicKey)))
  77         return fmt.Sprintf("%s %s", keyMaterial, comment), privateKeyBuffer.String(), nil
  78 }
  79
  80 // Seeds random with current timestamp
  81 func reseed() {
  82         rand.Seed(time.Now().UTC().UnixNano())
  83 }
  84
  85 const (
  86         // CharSetAlphaNum is the alphanumeric character set for use with
  87         // RandStringFromCharSet
  88         CharSetAlphaNum = "abcdefghijklmnopqrstuvwxyz012346789"
  89
  90         // CharSetAlpha is the alphabetical character set for use with
  91         // RandStringFromCharSet
  92         CharSetAlpha = "abcdefghijklmnopqrstuvwxyz"
  93 )