discovery: Deprecate usage of Consul's internal testutil package

This commit removes the use case within the discovery package's tests that
depended on an internal Consul test package, `testutil`. We replace this with
our own TestServer object which is responsible for executing a locally installed
`consul` binary. Consul is installed by our Makefile target `tools` for local
development use.

Ref: #528

discovery/consul_test.go

@@ -3,9 +3,9 @@ package discovery
 import (
 	"fmt"
 	"testing"
+	"time"
 
 	consul "github.com/hashicorp/consul/api"
-	"github.com/hashicorp/consul/testutil"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -77,18 +77,18 @@ a Consul server for testing. The 'consul' binary must be in the $PATH
 ref https://github.com/hashicorp/consul/tree/master/testutil
 */
 
-var testServer *testutil.TestServer
+var testServer *TestServer
 
 func TestWithConsul(t *testing.T) {
 	var err error
-	testServer, err = testutil.NewTestServerConfigT(t, func(c *testutil.TestServerConfig) {
-		c.LogLevel = "err"
-	})
+	testServer, err = NewTestServer(8500)
 	if err != nil {
 		t.Fatal(err)
 	}
-
 	defer testServer.Stop()
+
+	time.Sleep(300 * time.Millisecond)
+
 	t.Run("TestConsulTTLPass", testConsulTTLPass)
 	t.Run("TestConsulReregister", testConsulReregister)
 	t.Run("TestConsulCheckForChanges", testConsulCheckForChanges)

discovery/test_server.go

@@ -0,0 +1,55 @@
+package discovery
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+)
+
+// TestServer represents a Consul server we can run our tests against. Depends
+// on a local `consul` binary installed into our environ's PATH.
+type TestServer struct {
+	cmd      *exec.Cmd
+	HTTPAddr string
+}
+
+// NewTestServer constructs a new TestServer by including the httpPort as well.
+func NewTestServer(httpPort int) (*TestServer, error) {
+	path, err := exec.LookPath("consul")
+	if err != nil || path == "" {
+		return nil, fmt.Errorf("consul not found on $PATH - download and install " +
+			"consul or skip this test")
+	}
+
+	args := []string{"agent", "-dev"}
+	cmd := exec.Command("consul", args...)
+	cmd.Stdout = io.Writer(os.Stdout)
+	cmd.Stderr = io.Writer(os.Stderr)
+	if err := cmd.Start(); err != nil {
+		return nil, errors.New("failed starting command")
+	}
+
+	httpAddr := fmt.Sprintf("127.0.0.1:%d", httpPort)
+
+	return &TestServer{
+		cmd:      cmd,
+		HTTPAddr: httpAddr,
+	}, nil
+}
+
+// Stop stops a TestServer
+func (s *TestServer) Stop() error {
+	if s.cmd == nil {
+		return nil
+	}
+
+	if s.cmd.Process != nil {
+		if err := s.cmd.Process.Signal(os.Interrupt); err != nil {
+			return errors.New("failed to kill consul server")
+		}
+	}
+
+	return s.cmd.Wait()
+}