Vendor containerd 2386062 and runtime-tools e29f3ca.

Signed-off-by: Lantao Liu <lantaol@google.com>

vendor/github.com/opencontainers/runtime-tools/validate/error.go

@@ -0,0 +1,110 @@
+package validate
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	rspec "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+// ComplianceLevel represents the OCI compliance levels
+type ComplianceLevel int
+
+const (
+	// MAY-level
+
+	// ComplianceMay represents 'MAY' in RFC2119
+	ComplianceMay ComplianceLevel = iota
+	// ComplianceOptional represents 'OPTIONAL' in RFC2119
+	ComplianceOptional
+
+	// SHOULD-level
+
+	// ComplianceShould represents 'SHOULD' in RFC2119
+	ComplianceShould
+	// ComplianceShouldNot represents 'SHOULD NOT' in RFC2119
+	ComplianceShouldNot
+	// ComplianceRecommended represents 'RECOMMENDED' in RFC2119
+	ComplianceRecommended
+	// ComplianceNotRecommended represents 'NOT RECOMMENDED' in RFC2119
+	ComplianceNotRecommended
+
+	// MUST-level
+
+	// ComplianceMust represents 'MUST' in RFC2119
+	ComplianceMust
+	// ComplianceMustNot represents 'MUST NOT' in RFC2119
+	ComplianceMustNot
+	// ComplianceShall represents 'SHALL' in RFC2119
+	ComplianceShall
+	// ComplianceShallNot represents 'SHALL NOT' in RFC2119
+	ComplianceShallNot
+	// ComplianceRequired represents 'REQUIRED' in RFC2119
+	ComplianceRequired
+)
+
+// ErrorCode represents the compliance content
+type ErrorCode int
+
+const (
+	// DefaultFilesystems represents the error code of default filesystems test
+	DefaultFilesystems ErrorCode = iota
+)
+
+// Error represents an error with compliance level and OCI reference
+type Error struct {
+	Level     ComplianceLevel
+	Reference string
+	Err       error
+}
+
+const referencePrefix = "https://github.com/opencontainers/runtime-spec/blob"
+
+var ociErrors = map[ErrorCode]Error{
+	DefaultFilesystems: Error{Level: ComplianceShould, Reference: "config-linux.md#default-filesystems"},
+}
+
+// ParseLevel takes a string level and returns the OCI compliance level constant
+func ParseLevel(level string) (ComplianceLevel, error) {
+	switch strings.ToUpper(level) {
+	case "MAY":
+		fallthrough
+	case "OPTIONAL":
+		return ComplianceMay, nil
+	case "SHOULD":
+		fallthrough
+	case "SHOULDNOT":
+		fallthrough
+	case "RECOMMENDED":
+		fallthrough
+	case "NOTRECOMMENDED":
+		return ComplianceShould, nil
+	case "MUST":
+		fallthrough
+	case "MUSTNOT":
+		fallthrough
+	case "SHALL":
+		fallthrough
+	case "SHALLNOT":
+		fallthrough
+	case "REQUIRED":
+		return ComplianceMust, nil
+	}
+
+	var l ComplianceLevel
+	return l, fmt.Errorf("%q is not a valid compliance level", level)
+}
+
+// NewError creates an Error by ErrorCode and message
+func NewError(code ErrorCode, msg string) error {
+	err := ociErrors[code]
+	err.Err = errors.New(msg)
+
+	return &err
+}
+
+// Error returns the error message with OCI reference
+func (oci *Error) Error() string {
+	return fmt.Sprintf("%s\nRefer to: %s/v%s/%s", oci.Err.Error(), referencePrefix, rspec.Version, oci.Reference)
+}