s3 cache client-side support

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/aws/aws-sdk-go-v2/config/local.go

@@ -0,0 +1,51 @@
+package config
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+)
+
+var lookupHostFn = net.LookupHost
+
+func isLoopbackHost(host string) (bool, error) {
+	ip := net.ParseIP(host)
+	if ip != nil {
+		return ip.IsLoopback(), nil
+	}
+
+	// Host is not an ip, perform lookup
+	addrs, err := lookupHostFn(host)
+	if err != nil {
+		return false, err
+	}
+	if len(addrs) == 0 {
+		return false, fmt.Errorf("no addrs found for host, %s", host)
+	}
+
+	for _, addr := range addrs {
+		if !net.ParseIP(addr).IsLoopback() {
+			return false, nil
+		}
+	}
+
+	return true, nil
+}
+
+func validateLocalURL(v string) error {
+	u, err := url.Parse(v)
+	if err != nil {
+		return err
+	}
+
+	host := u.Hostname()
+	if len(host) == 0 {
+		return fmt.Errorf("unable to parse host from local HTTP cred provider URL")
+	} else if isLoopback, err := isLoopbackHost(host); err != nil {
+		return fmt.Errorf("failed to resolve host %q, %v", host, err)
+	} else if !isLoopback {
+		return fmt.Errorf("invalid endpoint host, %q, only host resolving to loopback addresses are allowed", host)
+	}
+
+	return nil
+}