stunnerd

README

stunnerd: The STUNner gateway daemon

The stunnerd daemon implements the STUNner gateway dataplane.

The daemon supports two basic modes. For quick tests stunnerd can be configured as a TURN server by specifying a TURN network URI on the command line. For more complex scenarios, and especially for use in a Kubernetes cluster, stunnerd can take configuration from a config file. In addition, stunnerd implements a watch-mode, so that it can actively monitor the config file for updates and, once the config file has changed, automatically reconcile the TURN server to the new configuration. This mode is intended for use with the STUNner Kubernetes gateway operator: the operator watches the Kubernetes Gateway API resources and renders the active control plane configuration into a ConfigMap, which is then mapped into the stunnerd pod's filesystem so that the daemon can pick up the latest configuration using the watch mode.

Features

• Full Kubernetes integration for quick installation into any hosted or on-prem Kubernetes cluster.
• Dynamic reconciliation by enabling config-file watch mode.
• RFC 5389: Session Traversal Utilities for NAT (STUN)
• RFC 8656: Traversal Using Relays around NAT (TURN)
• RFC 6062: Traversal Using Relays around NAT (TURN) Extensions for TCP Allocations
• TURN transport over UDP, TCP, TLS/TCP and DTLS/UDP.
• Two authentication modes via the long-term STUN/TURN credential mechanism: plaintext using a static username/password pair, and longterm with dynamically generated time-scoped credentials.

Getting Started

Installation

As easy as with any Go program.

cd stunner
go build -o stunnerd cmd/stunnerd/main.go

Usage

The below command will open a stunnerd UDP listener at 127.0.0.1:5000, set plaintext authentication using the username/password pair user1/passwrd1, and raises the debug level to the maximum.

./stunnerd --log=all:TRACE turn://user1:passwd1@127.0.0.1:5000

Alternatively, run stunnerd in verbose mode with the config file taken from cmd/stunnerd/stunnerd.conf. Adding the flag -w will enable watch mode.

$ ./stunnerd -v -w -c cmd/stunnerd/stunnerd.conf

Type ./stunnerd to see a short description of the command line arguments supported by stunnerd.

In practice, you'll rarely need to run stunnerd directly: just fire up the prebuilt container image in Kubernetes and you should be good to go.

Configuration

Using the below configuration, stunnerd will open 4 STUNner listeners: two for accepting unencrypted connections at UDP/3478 and TCP/3478, and two for encrypted connections at TLS/TCP/3479 and DTLS/UDP/3479. For easier debugging, the port for the transport relay connections opened by stunnerd will be taken from [10000:19999] for the UDP listener, [20000:29999] for the TCP listener, etc. The daemon will use longterm authentication, with the shared secret read from the environment variable $STUNNER_SHARED_SECRET during initialization. The relay address is taken from the $STUNNER_ADDR environment variable.

version: v1alpha1
admin:
  name: my-stunnerd
  logLevel: all:DEBUG
  realm: "my-realm.example.com"
static:
  auth:
    type: longterm
    credentials:
      secret: $STUNNER_SHARED_SECRET
  listeners:
    - name: stunnerd-udp
      address: "$STUNNER_ADDR"
      protocol: udp
      port: 3478
      minPort: 10000
      maxPort: 19999
    - name: stunnerd-tcp
      address: "$STUNNER_ADDR"
      protocol: tcp
      port: 3478
      minPort: 20000
      maxPort: 29999
    - name: stunnerd-tls
      protocol: tls
      port: 3479
      minPort: 30000
      maxPort: 39999
      cert: "my-cert.cert"
      key: "my-key.key"
    - name: stunnerd-dtls
      protocol: dtls
      port: 3479
      cert: "my-cert.cert"
      key: "my-key.key"
      minPort: 40000
      maxPort: 49999

License

Copyright 2021-2022 by its authors. Some rights reserved. See AUTHORS.

MIT License - see LICENSE for full text.

Acknowledgments

Initial code adopted from pion/stun and pion/turn.