feat: adding telnet streamer support

docs/streamer_types.md

@@ -0,0 +1,81 @@
+# Streamer Types
+
+`gnetcli` supports different connection types (streamers) for connecting to network equipment: SSH, Telnet.
+
+## Supported Types
+
+### Unknown (StreamerType_unknown)
+- **Value**: `0`
+- **Description**: Unspecified connection type, server will determine based on port or default to SSH
+- **Usage**: When not explicitly set
+
+### SSH (StreamerType_ssh)
+- **Value**: `1`
+- **Description**: Connection via SSH protocol (default when unknown)
+- **Default port**: 22
+- **Features**:
+  - SSH tunnel support (ProxyJump)
+  - SSH Control Files support
+  - SSH Agent support
+  - Private key authentication
+  - SFTP for file transfers
+
+### Telnet (StreamerType_telnet)
+- **Value**: `2`
+- **Description**: Connection via Telnet protocol
+- **Default port**: 23
+- **Features**:
+  - Plain text connection
+  - Username/password authentication
+  - Custom port support
+
+## API Usage
+
+### Via gRPC
+The streamer type is specified in host parameters:
+
+```protobuf
+message HostParams {
+  string host = 1;
+  Credentials credentials = 2;
+  int32 port = 3;
+  string device = 4;
+  string ip = 5;
+  StreamerType streamer_type = 6;  // SSH or Telnet
+}
+```
+
+### Example Request
+```json
+{
+  "host": "192.168.1.1",
+  "cmd": "show version",
+  "host_params": {
+    "streamer_type": 2,
+    "port": 23,
+    "credentials": {
+      "login": "admin",
+      "password": "password"
+    }
+  }
+}
+```
+Note: `streamer_type: 2` for Telnet, `streamer_type: 1` for SSH, `streamer_type: 0` for unknown/auto-detect.
+
+## Choosing Streamer Type
+
+### SSH is recommended for:
+- Modern network equipment
+- Production environments where security is important
+- Devices supporting cryptographic authentication
+- Cases requiring file transfers
+
+### Telnet is suitable for:
+- Legacy equipment without SSH support
+- Lab and test environments
+- Devices with limited computational resources
+- Connection debugging and diagnostics
+
+## Default Configuration
+
+If `streamer_type` is not explicitly specified, SSH is used as the more secure default option.

grpc_sdk/python/gnetclisdk/__init__.py

@@ -0,0 +1,29 @@
+"""gnetcli SDK for Python"""
+
+from .client import (
+    Credentials,
+    File,
+    Gnetcli,
+    HostParams,
+    QA,
+    STREAMER_UNKNOWN,
+    STREAMER_SSH,
+    STREAMER_TELNET,
+)
+from .exceptions import (
+    DeviceConnectError,
+    GnetcliException,
+)
+
+__all__ = [
+    "Credentials",
+    "File",
+    "Gnetcli",
+    "HostParams",
+    "QA",
+    "STREAMER_UNKNOWN",
+    "STREAMER_SSH",
+    "STREAMER_TELNET",
+    "DeviceConnectError",
+    "GnetcliException",
+]

grpc_sdk/python/gnetclisdk/client.py

@@ -7,7 +7,7 @@
 from contextlib import asynccontextmanager
 from dataclasses import dataclass, field
 from functools import partial
-from typing import Any, AsyncIterator, List, Optional, Tuple, Dict, Callable
+from typing import Any, AsyncIterator, List, Optional, Tuple, Dict, Callable, Union
 
 import grpc
 from google.protobuf.message import Message
@@ -25,6 +25,10 @@
 SERVER_ENV = "GNETCLI_SERVER"
 GRPC_MAX_MESSAGE_LENGTH = 130 * 1024**2
 
+STREAMER_UNKNOWN = server_pb2.StreamerType_unknown
+STREAMER_SSH = server_pb2.StreamerType_ssh
+STREAMER_TELNET = server_pb2.StreamerType_telnet
+
 default_grpc_options: List[Tuple[str, Any]] = [
     ("grpc.max_concurrent_streams", 900),
     ("grpc.max_send_message_length", GRPC_MAX_MESSAGE_LENGTH),
@@ -72,6 +76,7 @@ class HostParams:
     hostname: Optional[str] = None
     credentials: Optional[Credentials] = None
     ip: Optional[str] = None
+    streamer_type: Optional[int] = None
 
     def make_pb(self) -> server_pb2.HostParams:
         creds_pb: Optional[server_pb2.Credentials] = None
@@ -83,6 +88,7 @@ def make_pb(self) -> server_pb2.HostParams:
             credentials=creds_pb,
             device=self.device,
             ip=self.ip,
+            streamer_type=self.streamer_type if self.streamer_type is not None else server_pb2.StreamerType_unknown,
         )
         return pbcmd
 
@@ -247,6 +253,8 @@ async def set_host_params(self, hostname: str, params: HostParams) -> None:
             port=params.port,
             credentials=params.credentials.make_pb(),
             device=params.device,
+            ip=params.ip,
+            streamer_type=params.streamer_type if params.streamer_type is not None else server_pb2.StreamerType_unknown,
         )
         _logger.debug("connect to %s", self._server)
         async with self._grpc_channel_fn(self._server, options=self._options) as channel:

pkg/server/devuath.go

@@ -48,7 +48,7 @@ func (m authApp) GetHostParams(host string, params *pb.HostParams) (hostParams,
 	if err != nil {
 		return hostParams{}, err
 	}
-	res := NewHostParams(creds, params.GetDevice(), ip, port, proxyJump, controlPath, connectHost)
+	res := NewHostParams(creds, params.GetDevice(), ip, port, proxyJump, controlPath, connectHost, params.GetStreamerType())
 	return res, nil
 }