e2e: Add a TestMain for cli plugins tests

This was omitted when these tests were added.

Adding this means that the tests now see the `$DOCKER_HOST` configured (via
`$TEST_DOCKER_HOST`) where they didn't before. In some cases (specifically the
`test-e2e-connhelper-ssh` case) this results in additional output on stderr
when `-D` (debug) is used:

    time="2019-04-03T11:10:27Z" level=debug msg="commandconn: starting ssh with [-l penguin 172.20.0.2 -- docker system dial-stdio]"

Address this by switching the affected test cases to use `-l info` instead of
`-D`, they all just require some option not specifically `-D`. Note that `info`
is the default log level so this is effectively a nop (which is good).

Signed-off-by: Ian Campbell <ijc@docker.com>

e2e/cli-plugins/main_test.go

@@ -0,0 +1,17 @@
+package cliplugins
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/docker/cli/internal/test/environment"
+)
+
+func TestMain(m *testing.M) {
+	if err := environment.Setup(); err != nil {
+		fmt.Println(err.Error())
+		os.Exit(3)
+	}
+	os.Exit(m.Run())
+}

e2e/cli-plugins/run_test.go

@@ -135,7 +135,7 @@ func TestHelpGood(t *testing.T) {
 	run, _, cleanup := prepare(t)
 	defer cleanup()
 
-	res := icmd.RunCmd(run("-D", "help", "helloworld"))
+	res := icmd.RunCmd(run("-l", "info", "help", "helloworld"))
 	res.Assert(t, icmd.Expected{
 		ExitCode: 0,
 		Err:      icmd.None,
@@ -150,7 +150,7 @@ func TestGoodHelp(t *testing.T) {
 	run, _, cleanup := prepare(t)
 	defer cleanup()
 
-	res := icmd.RunCmd(run("-D", "helloworld", "--help"))
+	res := icmd.RunCmd(run("-l", "info", "helloworld", "--help"))
 	res.Assert(t, icmd.Expected{
 		ExitCode: 0,
 		Err:      icmd.None,
@@ -159,7 +159,7 @@ func TestGoodHelp(t *testing.T) {
 	golden.Assert(t, res.Stdout(), "docker-help-helloworld.golden")
 	// Short -h should be the same, modulo the deprecation message
 	exp := shortHFlagDeprecated + res.Stdout()
-	res = icmd.RunCmd(run("-D", "helloworld", "-h"))
+	res = icmd.RunCmd(run("-l", "info", "helloworld", "-h"))
 	res.Assert(t, icmd.Expected{
 		ExitCode: 0,
 		// This should be identical to the --help case above
@@ -188,7 +188,7 @@ func TestHelpGoodSubcommand(t *testing.T) {
 	run, _, cleanup := prepare(t)
 	defer cleanup()
 
-	res := icmd.RunCmd(run("-D", "help", "helloworld", "goodbye"))
+	res := icmd.RunCmd(run("-l", "info", "help", "helloworld", "goodbye"))
 	res.Assert(t, icmd.Expected{
 		ExitCode: 0,
 		Err:      icmd.None,
@@ -203,7 +203,7 @@ func TestGoodSubcommandHelp(t *testing.T) {
 	run, _, cleanup := prepare(t)
 	defer cleanup()
 
-	res := icmd.RunCmd(run("-D", "helloworld", "goodbye", "--help"))
+	res := icmd.RunCmd(run("-l", "info", "helloworld", "goodbye", "--help"))
 	res.Assert(t, icmd.Expected{
 		ExitCode: 0,
 		Err:      icmd.None,