Postgres reader

Postgres reader provides message repository implementation for Postgres.

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_POSTGRES_READER_LOG_LEVEL	Service log level	info
MG_POSTGRES_READER_HTTP_HOST	Service HTTP host	localhost
MG_POSTGRES_READER_HTTP_PORT	Service HTTP port	9009
MG_POSTGRES_READER_HTTP_SERVER_CERT	Service HTTP server cert	""
MG_POSTGRES_READER_HTTP_SERVER_KEY	Service HTTP server key	""
MG_POSTGRES_HOST	Postgres DB host	localhost
MG_POSTGRES_PORT	Postgres DB port	5432
MG_POSTGRES_USER	Postgres user	magistrala
MG_POSTGRES_PASS	Postgres password	magistrala
MG_POSTGRES_NAME	Postgres database name	messages
MG_POSTGRES_SSL_MODE	Postgres SSL mode	disabled
MG_POSTGRES_SSL_CERT	Postgres SSL certificate path	""
MG_POSTGRES_SSL_KEY	Postgres SSL key	""
MG_POSTGRES_SSL_ROOT_CERT	Postgres SSL root certificate path	""
MG_THINGS_AUTH_GRPC_URL	Things service Auth gRPC URL	localhost:7000
MG_THINGS_AUTH_GRPC_TIMEOUT	Things service Auth gRPC timeout in seconds	1s
MG_THINGS_AUTH_GRPC_CLIENT_TLS	Things service Auth gRPC TLS mode flag	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 mode flag	false
MG_AUTH_GRPC_CA_CERTS	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_POSTGRES_READER_INSTANCE_ID	Postgres reader instance ID

Deployment

The service itself is distributed as Docker container. Check the postgres-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 postgres writer
make postgres-writer

# copy binary to bin
make install

# Set the environment variables and run the service
MG_POSTGRES_READER_LOG_LEVEL=[Service log level] \
MG_POSTGRES_READER_HTTP_HOST=[Service HTTP host] \
MG_POSTGRES_READER_HTTP_PORT=[Service HTTP port] \
MG_POSTGRES_READER_HTTP_SERVER_CERT=[Service HTTPS server certificate path] \
MG_POSTGRES_READER_HTTP_SERVER_KEY=[Service HTTPS server key path] \
MG_POSTGRES_HOST=[Postgres host] \
MG_POSTGRES_PORT=[Postgres port] \
MG_POSTGRES_USER=[Postgres user] \
MG_POSTGRES_PASS=[Postgres password] \
MG_POSTGRES_NAME=[Postgres database name] \
MG_POSTGRES_SSL_MODE=[Postgres SSL mode] \
MG_POSTGRES_SSL_CERT=[Postgres SSL cert] \
MG_POSTGRES_SSL_KEY=[Postgres SSL key] \
MG_POSTGRES_SSL_ROOT_CERT=[Postgres SSL Root cert] \
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 mode flag] \
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 mode flag] \
MG_AUTH_GRPC_CA_CERTS=[Auth service gRPC CA certificates] \
MG_JAEGER_URL=[Jaeger server URL] \
MG_SEND_TELEMETRY=[Send telemetry to magistrala call home server] \
MG_POSTGRES_READER_INSTANCE_ID=[Postgres reader instance ID] \
$GOBIN/magistrala-postgres-reader

Usage

Starting service will start consuming normalized messages in SenML format.

Comparator Usage Guide:

Comparator	Usage	Example
eq	Return values that are equal to the query	eq["active"] -> "active"
ge	Return values that are substrings of the query	ge["tiv"] -> "active" and "tiv"
gt	Return values that are substrings of the query and not equal to the query	gt["tiv"] -> "active"
le	Return values that are superstrings of the query	le["active"] -> "tiv"
lt	Return values that are superstrings of the query and not equal to the query	lt["active"] -> "active" and "tiv"

Official docs can be found here.