Add test suite for push/pull code

Introduce the `DockerHubPullSuite` that interacts with its own dedicated
daemon, thus allowing to start from a clean environment and finely test
against the impact of isolated push and pull operations.

Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>

integration-cli/docker_hub_pull_suite_test.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"os/exec"
+	"strings"
+
+	"github.com/go-check/check"
+)
+
+func init() {
+	check.Suite(newDockerHubPullSuite())
+}
+
+// DockerHubPullSuite provides a isolated daemon that doesn't have all the
+// images that are baked into our 'global' test environment daemon (e.g.,
+// busybox, httpserver, ...).
+//
+// We use it for push/pull tests where we want to start fresh, and measure the
+// relative impact of each individual operation. As part of this suite, all
+// images are removed after each test.
+type DockerHubPullSuite struct {
+	d  *Daemon
+	ds *DockerSuite
+}
+
+// newDockerHubPullSuite returns a new instance of a DockerHubPullSuite.
+func newDockerHubPullSuite() *DockerHubPullSuite {
+	return &DockerHubPullSuite{
+		ds: &DockerSuite{},
+	}
+}
+
+// SetUpSuite starts the suite daemon.
+func (s *DockerHubPullSuite) SetUpSuite(c *check.C) {
+	s.d = NewDaemon(c)
+	if err := s.d.Start(); err != nil {
+		c.Fatalf("starting push/pull test daemon: %v", err)
+	}
+}
+
+// TearDownSuite stops the suite daemon.
+func (s *DockerHubPullSuite) TearDownSuite(c *check.C) {
+	if err := s.d.Stop(); err != nil {
+		c.Fatalf("stopping push/pull test daemon: %v", err)
+	}
+}
+
+// SetUpTest declares that all tests of this suite require network.
+func (s *DockerHubPullSuite) SetUpTest(c *check.C) {
+	testRequires(c, Network)
+}
+
+// TearDownTest removes all images from the suite daemon.
+func (s *DockerHubPullSuite) TearDownTest(c *check.C) {
+	out := s.Cmd(c, "images", "-aq")
+	images := strings.Split(out, "\n")
+	images = append([]string{"-f"}, images...)
+	s.d.Cmd("rmi", images...)
+	s.ds.TearDownTest(c)
+}
+
+// Cmd executes a command against the suite daemon and returns the combined
+// output. The function fails the test when the command returns an error.
+func (s *DockerHubPullSuite) Cmd(c *check.C, name string, arg ...string) string {
+	out, err := s.CmdWithError(name, arg...)
+	c.Assert(err, check.IsNil, check.Commentf("%q failed with errors: %s, %v", strings.Join(arg, " "), out, err))
+	return out
+}
+
+// CmdWithError executes a command against the suite daemon and returns the
+// combined output as well as any error.
+func (s *DockerHubPullSuite) CmdWithError(name string, arg ...string) (string, error) {
+	c := s.MakeCmd(name, arg...)
+	b, err := c.CombinedOutput()
+	return string(b), err
+}
+
+// MakeCmd returns a exec.Cmd command to run against the suite daemon.
+func (s *DockerHubPullSuite) MakeCmd(name string, arg ...string) *exec.Cmd {
+	args := []string{"--host", s.d.sock(), name}
+	args = append(args, arg...)
+	return exec.Command(dockerBinary, args...)
+}