implement CLI init cluster, add SSH and WireGuard cluster connectors

internal/cli/client/client.go

@@ -0,0 +1,41 @@
+package client
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"google.golang.org/grpc"
+	"uncloud/internal/machine/api/pb"
+)
+
+type Client struct {
+	connector Connector
+	conn      *grpc.ClientConn
+
+	pb.MachineClient
+}
+
+// Connector is an interface for establishing a connection to the machine API.
+type Connector interface {
+	Connect(ctx context.Context) (*grpc.ClientConn, error)
+	Close() error
+}
+
+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)
+	return c, nil
+}
+
+func (c *Client) Close() error {
+	err := c.conn.Close()
+	return errors.Join(err, c.connector.Close())
+}