Fix Windows CI fail due to GH13866 and patch up tests

Signed-off-by: John Howard <jhoward@microsoft.com>

integration-cli/docker_cli_links_unix_test.go

@@ -0,0 +1,58 @@
+// +build !windows
+
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/go-check/check"
+)
+
+func (s *DockerSuite) TestLinksEtcHostsRegularFile(c *check.C) {
+	runCmd := exec.Command(dockerBinary, "run", "--net=host", "busybox", "ls", "-la", "/etc/hosts")
+	out, _, _, err := runCommandWithStdoutStderr(runCmd)
+	if err != nil {
+		c.Fatal(out, err)
+	}
+
+	if !strings.HasPrefix(out, "-") {
+		c.Errorf("/etc/hosts should be a regular file")
+	}
+}
+
+func (s *DockerSuite) TestLinksEtcHostsContentMatch(c *check.C) {
+	testRequires(c, SameHostDaemon)
+
+	runCmd := exec.Command(dockerBinary, "run", "--net=host", "busybox", "cat", "/etc/hosts")
+	out, _, _, err := runCommandWithStdoutStderr(runCmd)
+	if err != nil {
+		c.Fatal(out, err)
+	}
+
+	hosts, err := ioutil.ReadFile("/etc/hosts")
+	if os.IsNotExist(err) {
+		c.Skip("/etc/hosts does not exist, skip this test")
+	}
+
+	if out != string(hosts) {
+		c.Errorf("container")
+	}
+
+}
+
+func (s *DockerSuite) TestLinksNetworkHostContainer(c *check.C) {
+
+	out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "run", "-d", "--net", "host", "--name", "host_container", "busybox", "top"))
+	if err != nil {
+		c.Fatal(err, out)
+	}
+
+	out, _, err = runCommandWithOutput(exec.Command(dockerBinary, "run", "--name", "should_fail", "--link", "host_container:tester", "busybox", "true"))
+	if err == nil || !strings.Contains(out, "--net=host can't be used with links. This would result in undefined behavior") {
+		c.Fatalf("Running container linking to a container with --net host should have failed: %s", out)
+	}
+
+}