Move specific errors to their respective packages

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

error.go

@@ -0,0 +1,32 @@
+/*
+   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 (
+	"github.com/pkg/errors"
+)
+
+var (
+	// ErrNoGRPCAndService is returned when no connection or service is available
+	ErrNoGRPCAndService = errors.New("no grpc connection and service is available")
+	// ErrReconnectFailed is returned when no connector is available to reconnect
+	ErrReconnectFailed = errors.New("unable to reconnect to containerd, no connector available")
+	// ErrNoGRPC is returned when no grpc connect is available
+	ErrNoGRPC = errors.New("no grpc connection available")
+	// ErrUnpackNotSupported is returned when a fetch cannot unpack
+	ErrUnpackNotSupported = errors.New("unpack on fetch not supported, try pull")
+)