WebSocket adapter

WebSocket adapter provides a WebSocket API for sending and receiving messages through the platform.

Configuration

The service is configured using the environment variables presented in the following table. Note that any unset variables will be replaced with their default values.

Variable	Description	Default
SMQ_WS_ADAPTER_LOG_LEVEL	Log level for the WS Adapter (debug, info, warn, error)	info
SMQ_WS_ADAPTER_HTTP_HOST	Service WS host	""
SMQ_WS_ADAPTER_HTTP_PORT	Service WS port	8190
SMQ_WS_ADAPTER_HTTP_SERVER_CERT	Path to the PEM encoded server certificate file	""
SMQ_WS_ADAPTER_HTTP_SERVER_KEY	Path to the PEM encoded server key file	""
SMQ_CLIENTS_AUTH_GRPC_URL	Clients service Auth gRPC URL	localhost:7000
SMQ_CLIENTS_AUTH_GRPC_TIMEOUT	Clients service Auth gRPC request timeout in seconds	1s
SMQ_CLIENTS_AUTH_GRPC_CLIENT_CERT	Path to the PEM encoded clients service Auth gRPC client certificate file	""
SMQ_CLIENTS_AUTH_GRPC_CLIENT_KEY	Path to the PEM encoded clients service Auth gRPC client key file	""
SMQ_CLIENTS_AUTH_GRPC_SERVER_CERTS	Path to the PEM encoded clients server Auth gRPC server trusted CA certificate file	""
SMQ_MESSAGE_BROKER_URL	Message broker instance URL	nats://localhost:4222
SMQ_JAEGER_URL	Jaeger server URL	http://localhost:4318/v1/traces
SMQ_JAEGER_TRACE_RATIO	Jaeger sampling ratio	1.0
SMQ_SEND_TELEMETRY	Send telemetry to supermq call home server	true
SMQ_WS_ADAPTER_INSTANCE_ID	Service instance ID	""

Deployment

The service is distributed as Docker container. Check the ws-adapter service section in docker-compose file to see how the service is deployed.

Running this service outside of container requires working instance of the message broker service, clients service and Jaeger server. To start the service outside of the container, execute the following shell script:

# download the latest version of the service
git clone https://github.com/absmach/supermq

cd supermq

# compile the ws
make ws

# copy binary to bin
make install

# set the environment variables and run the service
SMQ_WS_ADAPTER_LOG_LEVEL=info \
SMQ_WS_ADAPTER_HTTP_HOST=localhost \
SMQ_WS_ADAPTER_HTTP_PORT=8190 \
SMQ_WS_ADAPTER_HTTP_SERVER_CERT="" \
SMQ_WS_ADAPTER_HTTP_SERVER_KEY="" \
SMQ_CLIENTS_AUTH_GRPC_URL=localhost:7000 \
SMQ_CLIENTS_AUTH_GRPC_TIMEOUT=1s \
SMQ_CLIENTS_AUTH_GRPC_CLIENT_CERT="" \
SMQ_CLIENTS_AUTH_GRPC_CLIENT_KEY="" \
SMQ_CLIENTS_AUTH_GRPC_SERVER_CERTS="" \
SMQ_MESSAGE_BROKER_URL=nats://localhost:4222 \
SMQ_JAEGER_URL=http://localhost:14268/api/traces \
SMQ_JAEGER_TRACE_RATIO=1.0 \
SMQ_SEND_TELEMETRY=true \
SMQ_WS_ADAPTER_INSTANCE_ID="" \
$GOBIN/supermq-ws

Setting SMQ_WS_ADAPTER_HTTP_SERVER_CERT and SMQ_WS_ADAPTER_HTTP_SERVER_KEY will enable TLS against the service. The service expects a file in PEM format for both the certificate and the key.

Setting SMQ_CLIENTS_AUTH_GRPC_CLIENT_CERT and SMQ_CLIENTS_AUTH_GRPC_CLIENT_KEY will enable TLS against the clients service. The service expects a file in PEM format for both the certificate and the key. Setting SMQ_CLIENTS_AUTH_GRPC_SERVER_CERTS will enable TLS against the clients service trusting only those CAs that are provided. The service expects a file in PEM format of trusted CAs.

Usage

For more information about service capabilities and its usage, please check out the WebSocket section.