Separate go module for client tests

Will help us drop dependency to github.com/Microsoft/hcsshim/test in the
main go.mod

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

integration/client/client_unix_test.go

@@ -0,0 +1,73 @@
+// +build !windows
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package containerd
+
+import (
+	"runtime"
+	"testing"
+
+	. "github.com/containerd/containerd"
+	"github.com/containerd/containerd/platforms"
+)
+
+const (
+	defaultRoot    = "/var/lib/containerd-test"
+	defaultState   = "/run/containerd-test"
+	defaultAddress = "/run/containerd-test/containerd.sock"
+)
+
+var (
+	testImage    string
+	shortCommand = withProcessArgs("true")
+	longCommand  = withProcessArgs("/bin/sh", "-c", "while true; do sleep 1; done")
+)
+
+func init() {
+	switch runtime.GOARCH {
+	case "386":
+		testImage = "docker.io/i386/alpine:latest"
+	case "arm":
+		testImage = "docker.io/arm32v6/alpine:latest"
+	case "arm64":
+		testImage = "docker.io/arm64v8/alpine:latest"
+	case "ppc64le":
+		testImage = "docker.io/ppc64le/alpine:latest"
+	case "s390x":
+		testImage = "docker.io/s390x/alpine:latest"
+	default:
+		testImage = "docker.io/library/alpine:latest"
+	}
+}
+
+func TestImagePullSchema1WithEmptyLayers(t *testing.T) {
+	client, err := newClient(t, address)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer client.Close()
+
+	ctx, cancel := testContext(t)
+	defer cancel()
+
+	schema1TestImageWithEmptyLayers := "gcr.io/google-containers/busybox@sha256:d8d3bc2c183ed2f9f10e7258f84971202325ee6011ba137112e01e30f206de67"
+	_, err = client.Pull(ctx, schema1TestImageWithEmptyLayers, WithPlatform(platforms.DefaultString()), WithSchema1Conversion, WithPullUnpack)
+	if err != nil {
+		t.Fatal(err)
+	}
+}