Move ttrpc client to pkg/ttrpcutil

Signed-off-by: Maksym Pavlenko <makpav@amazon.com>

pkg/ttrpcutil/client.go

@@ -0,0 +1,105 @@
+/*
+   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 ttrpcutil
+
+import (
+	"sync"
+	"time"
+
+	v1 "github.com/containerd/containerd/api/services/ttrpc/events/v1"
+	"github.com/containerd/ttrpc"
+	"github.com/pkg/errors"
+)
+
+const ttrpcDialTimeout = 5 * time.Second
+
+type ttrpcConnector func() (*ttrpc.Client, error)
+
+// Client is the client to interact with TTRPC part of containerd server (plugins, events)
+type Client struct {
+	mu        sync.Mutex
+	connector ttrpcConnector
+	client    *ttrpc.Client
+	closed    bool
+}
+
+// NewClient returns a new containerd TTRPC client that is connected to the containerd instance provided by address
+func NewClient(address string, opts ...ttrpc.ClientOpts) (*Client, error) {
+	connector := func() (*ttrpc.Client, error) {
+		conn, err := ttrpcDial(address, ttrpcDialTimeout)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to connect")
+		}
+
+		client := ttrpc.NewClient(conn, opts...)
+		return client, nil
+	}
+
+	client, err := connector()
+	if err != nil {
+		return nil, err
+	}
+
+	return &Client{
+		connector: connector,
+		client:    client,
+	}, nil
+}
+
+// Reconnect re-establishes the TTRPC connection to the containerd daemon
+func (c *Client) Reconnect() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.connector == nil {
+		return errors.New("unable to reconnect to containerd, no connector available")
+	}
+
+	if c.closed {
+		return errors.New("client is closed")
+	}
+
+	client, err := c.connector()
+	if err != nil {
+		return err
+	}
+
+	c.client = client
+	return nil
+}
+
+// EventsService creates an EventsService client
+func (c *Client) EventsService() v1.EventsService {
+	return v1.NewEventsClient(c.Client())
+}
+
+// Client returns the underlying TTRPC client object
+func (c *Client) Client() *ttrpc.Client {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	return c.client
+}
+
+// Close closes the clients TTRPC connection to containerd
+func (c *Client) Close() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.closed = true
+	return c.client.Close()
+}

pkg/ttrpcutil/client_unix.go

@@ -0,0 +1,30 @@
+// +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 ttrpcutil
+
+import (
+	"net"
+	"strings"
+	"time"
+)
+
+func ttrpcDial(address string, timeout time.Duration) (net.Conn, error) {
+	address = strings.TrimPrefix(address, "unix://")
+	return net.DialTimeout("unix", address, timeout)
+}

pkg/ttrpcutil/client_windows.go

@@ -0,0 +1,60 @@
+// +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 ttrpcutil
+
+import (
+	"net"
+	"os"
+	"time"
+
+	winio "github.com/Microsoft/go-winio"
+	"github.com/pkg/errors"
+)
+
+func ttrpcDial(address string, timeout time.Duration) (net.Conn, error) {
+	var c net.Conn
+	var lastError error
+	timedOutError := errors.Errorf("timed out waiting for npipe %s", address)
+	start := time.Now()
+	for {
+		remaining := timeout - time.Since(start)
+		if remaining <= 0 {
+			lastError = timedOutError
+			break
+		}
+		c, lastError = winio.DialPipe(address, &remaining)
+		if lastError == nil {
+			break
+		}
+		if !os.IsNotExist(lastError) {
+			break
+		}
+		// There is nobody serving the pipe. We limit the timeout for this case
+		// to 5 seconds because any shim that would serve this endpoint should
+		// serve it within 5 seconds. We use the passed in timeout for the
+		// `DialPipe` timeout if the pipe exists however to give the pipe time
+		// to `Accept` the connection.
+		if time.Since(start) >= 5*time.Second {
+			lastError = timedOutError
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	return c, lastError
+}