Copy fuzzers from github.com/cncf/cncf-fuzzing

This commit copies the fuzzers from the repository except for
containerd_import_structured_fuzzer.go.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>

contrib/fuzz/daemon.go

@@ -0,0 +1,44 @@
+//go:build gofuzz
+// +build gofuzz
+
+/*
+   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 fuzz
+
+import (
+	"sync"
+	"time"
+
+	"github.com/containerd/containerd/cmd/containerd/command"
+)
+
+var (
+	initDaemon sync.Once
+)
+
+func startDaemonForFuzzing(arguments []string) {
+	app := command.App()
+	_ = app.Run(arguments)
+}
+
+func startDaemon() {
+	args := []string{"--log-level", "debug"}
+	go func() {
+		// This is similar to invoking the
+		// containerd binary.
+		// See contrib/fuzz/oss_fuzz_build.sh
+		// for more info.
+		startDaemonForFuzzing(args)
+	}()
+	time.Sleep(time.Second * 4)
+}