Adds Windows shim reconnect logs support

Signed-off-by: Justin Terry (VM) <juterry@microsoft.com>

runtime/v2/shim/shim_windows_test.go

@@ -0,0 +1,89 @@
+// +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 shim
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"testing"
+
+	winio "github.com/Microsoft/go-winio"
+	"github.com/containerd/containerd/namespaces"
+)
+
+func readValueFrom(rdr io.Reader, expectedStr string, t *testing.T) {
+	expected := []byte(expectedStr)
+	actual := make([]byte, len(expected))
+	read, err := rdr.Read(actual)
+	if err != nil {
+		t.Fatalf("failed to read with: %v", err)
+	}
+	if read != len(expected) {
+		t.Fatalf("failed to read len %v bytes read: %v", len(expected), actual)
+	}
+	if !bytes.Equal(expected, actual) {
+		t.Fatalf("expected '%v' != actual '%v'", expected, actual)
+	}
+}
+
+func writeValueTo(wr io.Writer, value string, t *testing.T) {
+	expected := []byte(value)
+	written, err := wr.Write(expected)
+	if err != nil {
+		t.Fatalf("failed to write with: %v", err)
+	}
+	if len(expected) != written {
+		t.Fatalf("failed to write len %v bytes wrote: %v", len(expected), written)
+	}
+}
+
+func runOneTest(ns, id string, writer io.Writer, t *testing.T) {
+	// Write on closed
+	go writeValueTo(writer, "Hello World!", t)
+
+	// Connect
+	c, err := winio.DialPipe(fmt.Sprintf("\\\\.\\pipe\\containerd-shim-%s-%s-log", ns, id), nil)
+	if err != nil {
+		t.Fatal("should have successfully connected to log")
+	}
+	defer c.Close()
+
+	// Read the deferred buffer.
+	readValueFrom(c, "Hello World!", t)
+
+	go writeValueTo(writer, "Hello Next!", t)
+	readValueFrom(c, "Hello Next!", t)
+}
+
+func TestOpenLog(t *testing.T) {
+	ns := "openlognamespace"
+	id := "openlogid"
+	ctx := namespaces.WithNamespace(context.TODO(), ns)
+	writer, err := openLog(ctx, id)
+	if err != nil {
+		t.Fatalf("failed openLog with %v", err)
+	}
+
+	// Do three iterations of write/open/read/write/read/close
+	for i := 0; i < 3; i++ {
+		runOneTest(ns, id, writer, t)
+	}
+}