remote: add additional connhelpers to buildx

Signed-off-by: Justin Chadwell <me@jedevc.com>

driver/remote/util/endpoint.go

@@ -0,0 +1,26 @@
+package remote
+
+import (
+	"net/url"
+
+	"github.com/pkg/errors"
+)
+
+var schemes = map[string]struct{}{
+	"tcp":              {},
+	"unix":             {},
+	"ssh":              {},
+	"docker-container": {},
+	"kube-pod":         {},
+}
+
+func IsValidEndpoint(ep string) error {
+	endpoint, err := url.Parse(ep)
+	if err != nil {
+		return errors.Wrapf(err, "failed to parse endpoint %s", ep)
+	}
+	if _, ok := schemes[endpoint.Scheme]; !ok {
+		return errors.Errorf("unrecognized url scheme %s", endpoint.Scheme)
+	}
+	return nil
+}