psmb

Proactive service library for modbusd

Environment variables

Why environment variable? Refer to the 12 factors

• CONF_PSMBTCP: config file path
• EP_BACKEND: endpoint of remote service discovery server (optional)

Contracts (Interfaces)

• IProactiveService: proactive service
• IReaderTaskDataStore: read/poll task data store
• IWriterTaskDataStore: write task data store
• IHistoryDataStore: history data store
• IFilterDataStore: filter data store
• IConfig: config management

Golang package management

• I adopted glide as package management system for this repository.

Worker Pool Model

Request from upstream

Response from downstream

Up and Running

Docker Compose

docker-compose build --pull
docker-compose up

Manually

Install libzmq (3.2.5)

wget https://github.com/zeromq/zeromq3-x/releases/download/v3.2.5/zeromq-3.2.5.tar.gz
tar xvzf zeromq-3.2.5.tar.gz
cd zeromq-3.2.5
./configure
make
sudo make install
sudo ldconfig

Build

# install glide
curl https://glide.sh/get | sh

# install dependencies
glide install

# build
cd tcp-srv
go build -o psmbtcp-srv

Continuous Integration

I do continuous integration and deploy docker images after git push by self-hosted drone.io server, circleci service, codecov service and dockerhub service.

Deployment Diagram

Unit tests

• binary
• types

Test cases

Binary

• [x] Bytes to 16-bit integer array tests
  • [x] BytesToUInt16s in big endian order - (1/4)
  • [x] BytesToUInt16s in little endian order - (2/4)
  • [x] BytesToInt16s in big endian order - (3/4)
  • [x] BytesToInt16s in little endian order - (4/4)
• [x] Bytes to 32-bit integer array tests
  • [x] BytesToUInt32s in (ABCD) Big Endian order - (1/4)
  • [x] BytesToUInt32s in (DCBA) Little Endian order - (2/4)
  • [x] BytesToUInt32s in (BADC) Mid-Big Endian order - (3/4)
  • [x] BytesToUInt32s in (CDAB) Mid-Little Endian order - (4/4)
  • [x] BytesToInt32s in (ABCD) Big Endian order - (1/4)
  • [x] BytesToInt32s in (DCBA) Little Endian order - (2/4)
  • [x] BytesToInt32s in (BADC) Mid-Big Endian order - (3/4)
  • [x] BytesToInt32s in (CDAB) Mid-Little Endian order - (4/4)
• [x] Bytes to 32-bit float array tests
  • [x] BytesToFloat32s in (ABCD) Big Endian order - (1/4)
  • [x] BytesToFloat32s in (DCBA) Little Endian order - (2/4)
  • [x] BytesToFloat32s in (BADC) Mid-Big Endian order - (3/4)
  • [x] BytesToFloat32s in (CDAB) Mid-Little Endian order - (4/4)
• [x] Bytes/registers utility tests
  • [x] BitStringToUInt8s test
  • [x] BitStringToUInt8s test - left comma
  • [x] BitStringToUInt8s test - right comma
  • [x] BitStringToUInt8s test - left, right comma
  • [x] RegistersToBytes test
  • [x] BytesToHexString test
  • [x] DecimalStringToRegisters test
  • [x] DecimalStringToRegisters test - left comma
  • [x] DecimalStringToRegisters test - right comma
  • [x] DecimalStringToRegisters test - left, right comma
  • [x] HexStringToRegisters test
  • [x] HexStringToRegisters test - wrong length
  • [x] LinearScalingRegisters test
  • [x] LinearScalingRegisters test - (0,0,0,0)
  • [x] LinearScalingRegisters test - reverse

Types

Upstream structure test

• [x] One-off modbus tcp struct tests
  • [x] mbtcp.once.read request test
  • [x] mbtcp.once.read response test
• [x] get/set modbus tcp timeout struct tests
  • [x] mbtcp.timeout.read request test
  • [x] mbtcp.timeout.read response test
  • [x] mbtcp.timeout.update request test
  • [x] mbtcp.timeout.update response test
  • [x] mbtcp.once.write request test
  • [x] mbtcp.once.write response test

Downstream structure test

• [x] modbus tcp downstreamstruct tests
  • [x] read request test
  • [x] single read response test
  • [x] multiple read response test
  • [x] single write request test
  • [x] multiple write request test
  • [x] set timeout request test
  • [x] get timeout response test

UML