grafana/pkg/util/shortid_generator.go
2024-06-20 12:56:39 +02:00

95 lines
2.6 KiB
Go

package util
import (
"errors"
"fmt"
"math/rand"
"regexp"
"sync"
"time"
"github.com/bwmarrin/snowflake"
"github.com/google/uuid"
)
const MaxUIDLength = 40
var uidrand = rand.New(rand.NewSource(time.Now().UnixNano()))
var alphaRunes = []rune("abcdefghijklmnopqrstuvwxyz")
var hexLetters = []rune("abcdef")
var (
ErrUIDTooLong = fmt.Errorf("UID is longer than %d symbols", MaxUIDLength)
ErrUIDFormatInvalid = errors.New("invalid format of UID. Only letters, numbers, '-' and '_' are allowed")
ErrUIDEmpty = fmt.Errorf("UID is empty")
)
// We want to protect our number generator as they are not thread safe. Not using
// the mutex could result in panics in certain cases where UIDs would be generated
// at the same time.
var mtx sync.Mutex
// Legacy UID pattern
var validUIDCharPattern = `a-zA-Z0-9\-\_`
var validUIDPattern = regexp.MustCompile(`^[` + validUIDCharPattern + `]*$`).MatchString
// IsValidShortUID checks if short unique identifier contains valid characters
// NOTE: future Grafana UIDs will need conform to https://github.com/kubernetes/apimachinery/blob/master/pkg/util/validation/validation.go#L43
func IsValidShortUID(uid string) bool {
return validUIDPattern(uid)
}
// IsShortUIDTooLong checks if short unique identifier is too long
func IsShortUIDTooLong(uid string) bool {
return len(uid) > MaxUIDLength
}
var node *snowflake.Node
// GenerateShortUID will generate a UUID that can also be a k8s name
// it is guaranteed to have a character as the first letter
// This UID will be a valid k8s name
func GenerateShortUID() string {
mtx.Lock()
defer mtx.Unlock()
if node == nil {
// ignoring the error happens when input outside 0-1023
node, _ = snowflake.NewNode(rand.Int63n(1024))
}
// Use UUIDs if snowflake failed (should be never)
if node == nil {
uid, err := uuid.NewRandom()
if err != nil {
// This should never happen... but this seems better than a panic
for i := range uid {
uid[i] = byte(uidrand.Intn(255))
}
}
uuid := uid.String()
if rune(uuid[0]) < rune('a') {
uuid = string(hexLetters[uidrand.Intn(len(hexLetters))]) + uuid[1:]
}
return uuid
}
return string(hexLetters[uidrand.Intn(len(hexLetters))]) + // start with a letter
node.Generate().Base36() +
string(hexLetters[uidrand.Intn(len(hexLetters))]) // a bit more entropy
}
// ValidateUID checks the format and length of the string and returns error if it does not pass the condition
func ValidateUID(uid string) error {
if len(uid) == 0 {
return ErrUIDEmpty
}
if IsShortUIDTooLong(uid) {
return ErrUIDTooLong
}
if !IsValidShortUID(uid) {
return ErrUIDFormatInvalid
}
return nil
}