Merge remote-tracking branch 'origin/main' into callback-endpoint

test/library/iplookup.go

@@ -0,0 +1,16 @@
+// Copyright 2020 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+// +build !go1.14
+
+package library
+
+import (
+	"context"
+	"net"
+)
+
+// LookupIP looks up the IP address of the provided hostname, preferring IPv4.
+func LookupIP(ctx context.Context, hostname string) ([]net.IP, error) {
+	return net.DefaultResolver.LookupIP(ctx, "ip4", hostname)
+}

test/library/iplookup_go1.14.go

@@ -0,0 +1,28 @@
+// Copyright 2020 the Pinniped contributors. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+// +build go1.14
+
+package library
+
+import (
+	"context"
+	"net"
+)
+
+// LookupIP looks up the IP address of the provided hostname, preferring IPv4.
+func LookupIP(ctx context.Context, hostname string) ([]net.IP, error) {
+	ips, err := net.DefaultResolver.LookupIPAddr(ctx, hostname)
+	if err != nil {
+		return nil, err
+	}
+
+	// Filter out to only IPv4 addresses
+	var results []net.IP
+	for _, ip := range ips {
+		if ip.IP.To4() != nil {
+			results = append(results, ip.IP)
+		}
+	}
+	return results, nil
+}