stunnerctl

stunnerctl: Command line toolbox for STUNner

A CLI tool to simplify the interaction with STUNner. The prominent use of stunnerctl is to load or watch STUNner dataplane configurations from a Kubernetes cluster for debugging and troubleshooting, or just for checking whether everything is configured the way it should be.

Installation

Install the stunnerctl binary using the standard Go toolchain and add it to $PATH.

go install github.com/l7mp/stunner/cmd/stunnerctl@latest

You can also enforce a specific OS, CPU architecture, and STUNner version:

GOOS=windows GOARCH=amd64 go install github.com/l7mp/stunner/cmd/stunnerctl@v0.17.5

Building from source is as easy as it usually gets with Go:

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

Usage

Type stunnerctl to get a glimpse of the sub-commands and features provided.

Config

The config sub-command is used to load or watch running dataplane configs from the STUNner config discovery service (CDS) running in a remote Kubernetes cluster. Usually the CDS server role is fulfilled by the STUNner gateway operator but you can choose any CDS service you want (see the --cds-server-* CLI flags in the help). The main use of this command is to check the active dataplane configuration for troubleshooting connectivity problems.

• Dump a summary of the running config of the STUNner gateway called udp-gateway deployed into the stunner namespace:

  stunnerctl -n stunner config udp-gateway
  Gateway: stunner/udp-gateway (loglevel: "all:INFO")
  Authentication type: static, username/password: user-1/pass-1
  Listeners:
    - Name: stunner/udp-gateway/udp-listener
      Protocol: TURN-UDP
      Public address:port: 34.118.88.91:9001
      Routes: [stunner/iperf-server]
      Endpoints: [10.76.1.3, 10.80.7.104]
  

• The same, but using the alternative Kubernetes config file ~/my-config.conf to access the cluster. The rest of the usual kubectl flags (--context, --token, etc.) are also available to select the cluster to connect to.

  stunnerctl --kubeconfig ~/my-config.conf -n stunner config udp-gateway
  

• Dump the running config of all gateways in the stunner namespace in JSON format (YAML is also available using -o yaml):

  stunnerctl -n stunner config -o json
  {"version":"v1","admin":{"name":"stunner/tcp-gateway",...}}
  {"version":"v1","admin":{"name":"stunner/udp-gateway",...}}}
  

• Watch STUNner configs as they are being refreshed by the operator and dump only the name of the gateway whose config changes:

  stunnerctl config --all-namespaces -o jsonpath='{.admin.name}' -w
  stunner/tcp-gateway
  stunner/udp-gateway
  ...
  

For those who don't have the Go toolchain available to run go install, STUNner provides a minimalistic stunnerctl replacement called stunnerctl.sh. This script requires nothing else than bash, kubectl, curl and jq to work.

The below will dump the running config of tcp-gateway deployed into the stunner namespace:

cd stunner
cmd/stunnerctl/stunnerctl.sh running-config stunner/tcp-gateway
STUN/TURN authentication type:  static
STUN/TURN username:             user-1
STUN/TURN password:             pass-1
Listener 1
        Name:   stunner/tcp-gateway/tcp-listener
        Listener:       stunner/tcp-gateway/tcp-listener
        Protocol:       TURN-TCP
        Public address: 35.187.97.94
        Public port:    3478

You can also use kubectl port-forward to load or watch STUNner configs manually. Open a port-forwarded connection to the STUNner gateway operator:

export CDS_SERVER_NAME=$(kubectl get pods -l stunner.l7mp.io/config-discovery-service=enabled --all-namespaces -o jsonpath='{.items[0].metadata.name}')
export CDS_SERVER_NAMESPACE=$(kubectl get pods -l stunner.l7mp.io/config-discovery-service=enabled --all-namespaces -o jsonpath='{.items[0].metadata.namespace}')
kubectl -n $CDS_SERVER_NAMESPACE port-forward pod/${CDS_SERVER_NAME} 63478:13478 &

If all goes well, you can now connect to the STUNner CDS API served by the gateway operator through the port-forwarded tunnel opened by kubectl just using curl. The below will load the config of the udp-gateway in the stunner namespace:

curl -s http://127.0.0.1:63478/api/v1/configs/stunner/udp-gateway

If you happen to have a WebSocket client like the wonderful websocat tool installed, you can also watch the configs as they are being rendered by the operator en live.

websocat ws://127.0.0.1:63478/api/v1/configs/stunner/udp-gateway?watch=true -

Status

The status sub-command reports the status of the dataplane pods for a gateway, especially the runtime state of the stunnerd daemon.

• Find all dataplane pods for the udp-gateway in the stunner namespace and dump a status summary:

  stunnerctl -n stunner status udp-gateway
  stunner/udp-gateway-856c9f4dc9-524hc:
  	stunner/udp-gateway:{logLevel="all:INFO",health-check="http://:8086"}
  	static-auth:{realm="stunner.l7mp.io",username="<SECRET>",password="<SECRET>"}
  	listeners:1/clusters:1
  	allocs:3/status=READY
  stunner/udp-gateway-856c9f4dc9-c7wcq:
  	stunner/udp-gateway:{logLevel="all:INFO",health-check="http://:8086"}
  	static-auth:{realm="stunner.l7mp.io",username="<SECRET>",password="<SECRET>"}
  	listeners:1/clusters:1
  	allocs:2/status=READY
  

• Same but report only the runtime status of the stunnerd pods in the stunner namespace:

  stunnerctl -n stunner status -o jsonpath='{.status}'
  READY
  TERMINATING
  

Authentication

The auth sub-command can be used to obtain a TURN credential or a full ICE server config for connecting to a specific gateway. The authentication service API is usually served by a separate STUNner authentication server deployed alongside the gateway operator. The main use of this command is to feed an ICE agent manually with the ICE server config to connect to a specific STUNner gateway.

• Obtain a full ICE server config for udp-gateway deployed into the stunner namespace:

  stunnerctl -n stunner auth udp-gateway
  {"iceServers":[{"credential":"pass-1","urls":["turn:10.104.19.179:3478?transport=udp"],"username":"user-1"}],"iceTransportPolicy":"all"}
  

• Request a plain TURN credential using the authentication service deployed into the stunner-system-prod namespace:

  stunnerctl -n stunner auth udp-gateway --auth-turn-credential --auth-service-namespace=stunner-system-prod
  {"password":"pass-1","ttl":86400,"uris":["turn:10.104.19.179:3478?transport=udp"],"username":"user-1"}
  

License

Copyright 2021-2023 by its authors. Some rights reserved. See AUTHORS.

MIT License - see LICENSE for full text.