integ-cli: skip tests launching registry-v2

Some pull/push tests are launching `registry-v2`
binary which is compiled and installed if the tests
are running in-container through `make test-integration-cli`.

However, registry is not supported to run on non-linux
platforms and we can't really spin up any registry-v2
containers in the remote DOCKER_TEST_HOST at this point.

Just skipping those with the new TestRequirement called
`RegistryHosting`.

Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>

integration-cli/docker_utils.go

@@ -901,6 +901,7 @@ func readContainerFileWithExec(containerId, filename string) ([]byte, error) {
 }
 
 func setupRegistry(t *testing.T) func() {
+	testRequires(t, RegistryHosting)
 	reg, err := newTestRegistryV2(t)
 	if err != nil {
 		t.Fatal(err)

integration-cli/requirements.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"fmt"
+	"os/exec"
 	"testing"
 )
 
@@ -25,6 +27,16 @@ var (
 		func() bool { return supportsExec },
 		"Test requires 'docker exec' capabilities on the tested daemon.",
 	}
+	RegistryHosting = TestRequirement{
+		func() bool {
+			// for now registry binary is built only if we're running inside
+			// container through `make test`. Figure that out by testing if
+			// registry binary is in PATH.
+			_, err := exec.LookPath(v2binary)
+			return err == nil
+		},
+		fmt.Sprintf("Test requires an environment that can host %s in the same host", v2binary),
+	}
 )
 
 // testRequires checks if the environment satisfies the requirements