Add health check test image. (#918)

tests/images/healthcheck/main.go

@@ -0,0 +1,31 @@
+/*
+  Copyright (c) Ansible Project
+  GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+  SPDX-License-Identifier: GPL-3.0-or-later
+*/
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"time"
+)
+
+func main() {
+	os.WriteFile("health.txt", []byte("starting"), 0644)
+	if len(os.Args) != 2 {
+		fmt.Fprintf(os.Stderr, "%s must have 1 argument, not %d arguments\n", os.Args[0], len(os.Args))
+		os.Exit(1)
+	}
+	delay, err := time.ParseDuration(os.Args[1])
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Cannot parse delay duration: %s\n", err)
+		os.Exit(1)
+	}
+	if delay.Microseconds() <= 0 {
+		fmt.Fprintf(os.Stderr, "Delay must be positive!\n")
+		os.Exit(1)
+	}
+	time.Sleep(delay)
+}