Add clean_ami_name for gcp

builder/googlecompute/templace_funcs.go

@@ -0,0 +1,44 @@
+package googlecompute
+
+import (
+	"regexp"
+	"strings"
+	"text/template"
+)
+
+func isalphanumeric(b byte) bool {
+	if '0' <= b && b <= '9' {
+		return true
+	}
+	if 'a' <= b && b <= 'z' {
+		return true
+	}
+	return false
+}
+
+// Clean up image name by replacing invalid characters with "-"
+// truncate up to 63 length, convert to a lower case
+func templateCleanAMIName(s string) string {
+	re := regexp.MustCompile(`^[a-z][-a-z0-9]{0,61}[a-z0-9]$`)
+	if re.MatchString(s) {
+		return s
+	}
+	b := []byte(strings.ToLower(s))
+	l := 63
+	if len(b) < 63 {
+		l = len(b)
+	}
+	newb := make([]byte, l)
+	for i := range newb {
+		if isalphanumeric(b[i]) {
+			newb[i] = b[i]
+		} else {
+			newb[i] = '-'
+		}
+	}
+	return string(newb)
+}
+
+var TemplateFuncs = template.FuncMap{
+	"clean_ami_name": templateCleanAMIName,
+}

builder/googlecompute/templace_funcs_test.go

@@ -0,0 +1,34 @@
+package googlecompute
+
+import "testing"
+
+func Test_templateCleanAMIName(t *testing.T) {
+	vals := []struct {
+		origName string
+		expected string
+	}{
+		{
+			origName: "abcde-012345xyz",
+			expected: "abcde-012345xyz",
+		},
+		{
+			origName: "ABCDE-012345xyz",
+			expected: "abcde-012345xyz",
+		},
+		{
+			origName: "abcde-012345v1.0.0",
+			expected: "abcde-012345v1-0-0",
+		},
+		{
+			origName: "0123456789012345678901234567890123456789012345678901234567890123456789",
+			expected: "012345678901234567890123456789012345678901234567890123456789012",
+		},
+	}
+
+	for _, v := range vals {
+		name := templateCleanAMIName(v.origName)
+		if name != v.expected {
+			t.Fatalf("template names do not match: expected %s got %s\n", v.expected, name)
+		}
+	}
+}