TUN-528: Move cloudflared into a separate repo

cmd/cloudflared/tag.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"regexp"
+
+	tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
+)
+
+// Restrict key names to characters allowed in an HTTP header name.
+// Restrict key values to printable characters (what is recognised as data in an HTTP header value).
+var tagRegexp = regexp.MustCompile("^([a-zA-Z0-9!#$%&'*+\\-.^_`|~]+)=([[:print:]]+)$")
+
+func NewTagFromCLI(compoundTag string) (tunnelpogs.Tag, bool) {
+	matches := tagRegexp.FindStringSubmatch(compoundTag)
+	if len(matches) == 0 {
+		return tunnelpogs.Tag{}, false
+	}
+	return tunnelpogs.Tag{Name: matches[1], Value: matches[2]}, true
+}
+
+func NewTagSliceFromCLI(tags []string) ([]tunnelpogs.Tag, error) {
+	var tagSlice []tunnelpogs.Tag
+	for _, compoundTag := range tags {
+		if tag, ok := NewTagFromCLI(compoundTag); ok {
+			tagSlice = append(tagSlice, tag)
+		} else {
+			return nil, fmt.Errorf("Cannot parse tag value %s", compoundTag)
+		}
+	}
+	return tagSlice, nil
+}