image.go RawHistoryFolder

1package validation
2
3import (
4	"fmt"
5	"strings"
6)
7
8const sha256DigestLength = len("sha256:") + 64
9
10// ValidateImageDigest validates the only digest format accepted for image
11// references and resolved deployment pins: sha256 followed by exactly 64
12// lowercase hexadecimal characters.
13func ValidateImageDigest(digest string) error {
14	if len(digest) != sha256DigestLength || !strings.HasPrefix(digest, "sha256:") {
15		return fmt.Errorf("image digest must be sha256:<64 hex chars>")
16	}
17	for _, c := range digest[len("sha256:"):] {
18		if (c < '0' || c > '9') && (c < 'a' || c > 'f') {
19			return fmt.Errorf("image digest must be sha256:<64 hex chars>")
20		}
21	}
22	return nil
23}
24
25// ParseImageReference parses an image reference into name and tag/digest.
26// Supports formats:
27//   - image:tag (default tag is "latest")
28//   - image@sha256:... (digest)
29//   - image (defaults to "latest")
30//   - registry.example.com/image:tag
31//   - registry.example.com/image@sha256:...
32//
33// Returns:
34//   - name: the image name (including registry if specified)
35//   - reference: the tag (e.g., "latest") or digest (e.g., "sha256:...")
36func ParseImageReference(imageRef string) (string, string) {
37	// Check for digest reference (@sha256:...)
38	if idx := strings.Index(imageRef, "@sha256:"); idx != -1 {
39		return imageRef[:idx], imageRef[idx+1:] // Return name and full digest
40	}
41
42	// Check for tag reference (:tag)
43	if idx := strings.Index(imageRef, ":"); idx != -1 {
44		// Check if this is actually a port number (e.g., registry:5000/image)
45		// by looking for a slash before the colon
46		if slashIdx := strings.Index(imageRef, "/"); slashIdx != -1 && slashIdx > idx {
47			// Slash comes after colon, so colon is part of registry port
48			// Look for another colon for the tag
49			if tagIdx := strings.Index(imageRef[slashIdx:], ":"); tagIdx != -1 {
50				actualTagIdx := slashIdx + tagIdx
51				return imageRef[:actualTagIdx], imageRef[actualTagIdx+1:]
52			}
53			return imageRef, "latest"
54		}
55		return imageRef[:idx], imageRef[idx+1:] // Return name and tag
56	}
57
58	// Default to "latest" tag
59	return imageRef, "latest"
60}