cassandra

README

Cassandra writer

Cassandra writer provides message repository implementation for Cassandra.

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
MG_CASSANDRA_WRITER_LOG_LEVEL	Log level for Cassandra writer (debug, info, warn, error)	info
MG_CASSANDRA_WRITER_CONFIG_PATH	Config file path with NATS subjects list, payload type and content-type	/config.toml
MG_CASSANDRA_WRITER_HTTP_HOST	Cassandra service HTTP host
MG_CASSANDRA_WRITER_HTTP_PORT	Cassandra service HTTP port	9004
MG_CASSANDRA_WRITER_HTTP_SERVER_CERT	Cassandra service HTTP server certificate path
MG_CASSANDRA_WRITER_HTTP_SERVER_KEY	Cassandra service HTTP server key path
MG_CASSANDRA_CLUSTER	Cassandra cluster comma separated addresses	127.0.0.1
MG_CASSANDRA_KEYSPACE	Cassandra keyspace name	magistrala
MG_CASSANDRA_USER	Cassandra DB username	magistrala
MG_CASSANDRA_PASS	Cassandra DB password	magistrala
MG_CASSANDRA_PORT	Cassandra DB port	9042
MG_MESSAGE_BROKER_URL	Message broker instance URL	nats://localhost:4222
MG_JAEGER_URL	Jaeger server URL	http://jaeger:14268/api/traces
MG_SEND_TELEMETRY	Send telemetry to magistrala call home server	true
MG_CASSANDRA_WRITER_INSTANCE_ID	Cassandra writer instance ID

Deployment

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

To start the service, execute the following shell script:

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

cd magistrala

# compile the cassandra writer
make cassandra-writer

# copy binary to bin
make install

# Set the environment variables and run the service
MG_CASSANDRA_WRITER_LOG_LEVEL=[Cassandra writer log level] \
MG_CASSANDRA_WRITER_CONFIG_PATH=[Config file path with NATS subjects list, payload type and content-type] \
MG_CASSANDRA_WRITER_HTTP_HOST=[Cassandra service HTTP host] \
MG_CASSANDRA_WRITER_HTTP_PORT=[Cassandra service HTTP port] \
MG_CASSANDRA_WRITER_HTTP_SERVER_CERT=[Cassandra service HTTP server cert] \
MG_CASSANDRA_WRITER_HTTP_SERVER_KEY=[Cassandra service HTTP server key] \
MG_CASSANDRA_CLUSTER=[Cassandra cluster comma separated addresses] \
MG_CASSANDRA_KEYSPACE=[Cassandra keyspace name] \
MG_CASSANDRA_USER=[Cassandra DB username] \
MG_CASSANDRA_PASS=[Cassandra DB password] \
MG_CASSANDRA_PORT=[Cassandra DB port] \
MG_MESSAGE_BROKER_URL=[Message Broker instance URL] \
MG_JAEGER_URL=[Jaeger server URL] \
MG_SEND_TELEMETRY=[Send telemetry to magistrala call home server] \
MG_CASSANDRA_WRITER_INSTANCE_ID=[Cassandra writer instance ID] \
$GOBIN/magistrala-cassandra-writer

Using docker-compose

This service can be deployed using docker containers. Docker compose file is available in <project_root>/docker/addons/cassandra-writer/docker-compose.yml. In order to run all Magistrala core services, as well as mentioned optional ones, execute following command:

./docker/addons/cassandra-writer/init.sh

Usage

Starting service will start consuming normalized messages in SenML format.

Documentation

Overview

Package cassandra contains the domain concept definitions needed to support Magistrala Cassandra writer service.

Index

• Constants
• func New(session *gocql.Session) consumers.BlockingConsumer

Constants

const (
	// Table contains query for default table created in cassandra db.
	Table = `` /* 452-byte string literal not displayed */

)

Functions

func New

func New(session *gocql.Session) consumers.BlockingConsumer

New instantiates Cassandra message repository.