cassandra

README

Cassandra reader

Cassandra reader 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_READER_LOG_LEVEL	Cassandra service log level	debug
MG_CASSANDRA_READER_HTTP_HOST	Cassandra service HTTP host	localhost
MG_CASSANDRA_READER_HTTP_PORT	Cassandra service HTTP port	9003
MG_CASSANDRA_READER_HTTP_SERVER_CERT	Cassandra service HTTP server cert	""
MG_CASSANDRA_READER_HTTP_SERVER_KEY	Cassandra service HTTP server key	""
MG_CASSANDRA_CLUSTER	Cassandra cluster comma separated addresses	localhost
MG_CASSANDRA_USER	Cassandra DB username	magistrala
MG_CASSANDRA_PASS	Cassandra DB password	magistrala
MG_CASSANDRA_KEYSPACE	Cassandra keyspace name	messages
MG_CASSANDRA_PORT	Cassandra DB port	9042
MG_THINGS_AUTH_GRPC_URL	Things service Auth gRPC URL	localhost:7000
MG_THINGS_AUTH_GRPC_TIMEOUT	Things service Auth gRPC request timeout in seconds	1
MG_THINGS_AUTH_GRPC_CLIENT_TLS	Things service Auth gRPC TLS enabled	false
MG_THINGS_AUTH_GRPC_CA_CERTS	Things service Auth gRPC CA certificates	""
MG_AUTH_GRPC_URL	Auth service gRPC URL	localhost:7001
MG_AUTH_GRPC_TIMEOUT	Auth service gRPC request timeout in seconds	1s
MG_AUTH_GRPC_CLIENT_TLS	Auth service gRPC TLS enabled	false
MG_AUTH_GRPC_CA_CERT	Auth service gRPC CA certificates	""
MG_JAEGER_URL	Jaeger server URL	http://jaeger:14268/api/traces
MG_SEND_TELEMETRY	Send telemetry to magistrala call home server	true
MG_CASSANDRA_READER_INSTANCE_ID	Cassandra Reader instance ID	""

Deployment

The service itself is distributed as Docker container. Check the cassandra-reader service section in docker-compose 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
make cassandra-reader

# copy binary to bin
make install

# Set the environment variables and run the service
MG_CASSANDRA_READER_LOG_LEVEL=[Cassandra Service log level] \
MG_CASSANDRA_READER_HTTP_HOST=[Cassandra Service HTTP host] \
MG_CASSANDRA_READER_HTTP_PORT=[Cassandra Service HTTP port] \
MG_CASSANDRA_READER_HTTP_SERVER_CERT=[Cassandra Service HTTP server cert] \
MG_CASSANDRA_READER_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_THINGS_AUTH_GRPC_URL=[Things service Auth gRPC URL] \
MG_THINGS_AUTH_GRPC_TIMEOUT=[Things service Auth gRPC request timeout in seconds] \
MG_THINGS_AUTH_GRPC_CLIENT_TLS=[Things service Auth gRPC TLS enabled] \
MG_THINGS_AUTH_GRPC_CA_CERTS=[Things service Auth gRPC CA certificates] \
MG_AUTH_GRPC_URL=[Auth service gRPC URL] \
MG_AUTH_GRPC_TIMEOUT=[Auth service gRPC request timeout in seconds] \
MG_AUTH_GRPC_CLIENT_TLS=[Auth service gRPC TLS enabled] \
MG_AUTH_GRPC_CA_CERT=[Auth service gRPC CA certificates] \
MG_JAEGER_URL=[Jaeger server URL] \
MG_SEND_TELEMETRY=[Send telemetry to magistrala call home server] \
MG_CASSANDRA_READER_INSTANCE_ID=[Cassandra Reader instance ID] \
$GOBIN/magistrala-cassandra-reader

Using docker-compose

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

docker-compose -f docker/docker-compose.yml up -d
./docker/addons/cassandra-writer/init.sh
docker-compose -f docker/addons/casandra-reader/docker-compose.yml up -d

Usage

Service exposes HTTP API for fetching messages.

Note: Cassandra Reader doesn't support searching substrings from string_value, due to inefficient searching as the current data model is not suitable for this type of queries.

Documentation

Overview

Package cassandra contains Cassandra specific reader implementation.

Index

• func New(session *gocql.Session) readers.MessageRepository

Functions

func New

func New(session *gocql.Session) readers.MessageRepository

New instantiates Cassandra message repository.