refactor: move api, client, compose packages to pkg

pkg/client/client.go

@@ -0,0 +1,67 @@
+package client
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"github.com/docker/cli/cli/streams"
+	"github.com/psviderski/uncloud/internal/machine/api/pb"
+	"github.com/psviderski/uncloud/internal/machine/docker"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+	"os"
+)
+
+var ErrNotFound = errors.New("not found")
+
+// Client is a client for the machine API.
+type Client struct {
+	connector Connector
+	conn      *grpc.ClientConn
+
+	pb.MachineClient
+	pb.ClusterClient
+	// Docker is a namespaced client for the Docker service to distinguish Uncloud-specific service container operations
+	// from generic Docker operations.
+	Docker *docker.Client
+}
+
+// Connector is an interface for establishing a connection to the machine API.
+type Connector interface {
+	Connect(ctx context.Context) (*grpc.ClientConn, error)
+	Close() error
+}
+
+// New creates a new client for the machine API. The connector is used to establish the connection
+// either locally or remotely. The client is responsible for closing the connector.
+func New(ctx context.Context, connector Connector) (*Client, error) {
+	c := &Client{
+		connector: connector,
+	}
+	var err error
+	c.conn, err = connector.Connect(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("connect to machine: %w", err)
+	}
+
+	c.MachineClient = pb.NewMachineClient(c.conn)
+	c.ClusterClient = pb.NewClusterClient(c.conn)
+	c.Docker = docker.NewClient(c.conn)
+	return c, nil
+}
+
+func (cli *Client) Close() error {
+	return errors.Join(cli.conn.Close(), cli.connector.Close())
+}
+
+// progressOut returns an output stream for progress writer.
+func (cli *Client) progressOut() *streams.Out {
+	return streams.NewOut(os.Stdout)
+}
+
+// proxyToMachine returns a new context that proxies gRPC requests to the specified machine.
+func proxyToMachine(ctx context.Context, machine *pb.MachineInfo) context.Context {
+	machineIP, _ := machine.Network.ManagementIp.ToAddr()
+	md := metadata.Pairs("machines", machineIP.String())
+	return metadata.NewOutgoingContext(ctx, md)
+}