gm-mint-sender

README

A set of GM Mint blockchain services.

Watcher

Watcher service listens Mint blockchain for a new blocks/transactions and detects wallets' incoming transactions.
ROI (e.g. a set of wallets to observe) could be changed via requests to the service.
Incoming transactions are saved into storage. Upon saving, the service tries to notify it's consumer.

Usage

Prepare config.yaml:

# Log
log:
  level: info
  color: yes
  json: no
# API (one of)
api:
  # Nats interface (optional)
  nats:
    url: localhost:4222
    prefix: ""
  # HTTP interface (optional)
  http:
    port: 9000
# Database
db:
  driver: mysql
  dsn: user:password@tcp(localhost:3306)/mint_sender?collation=utf8_general_ci&timeout=10s&readTimeout=60s&writeTimeout=60s
  prefix: watcher
# Prometheus metrics (optional)
metrics: 2113
# Mint nodes
nodes:
  - 127.0.0.1:4010

Run the service:

./watcher

Nats messages HTTP messages

Sender

Sender service handles a queue of payments (outgoing transactions).
Serves requests to send tokens to the client's wallet from a set of predefined wallets (taking balances into account).
Upon succesful sending, the service tries to notify it's consumers.

Usage

Prepare config.yaml:

# Log
log:
  level: debug
  color: yes
  json: no
# API (one of)
api:
  # Nats interface (optional)
  nats:
    url: localhost:4222
    prefix: ""
  # HTTP interface (optional)
  http:
    port: 9001
# Database
db:
  driver: mysql
  dsn: user:password@tcp(localhost:3306)/mint_sender?collation=utf8_general_ci&timeout=10s&readTimeout=60s&writeTimeout=60s
  prefix: sender
# Prometheus metrics (optional)
metrics: 2114
# Mint nodes
nodes:
  - 127.0.0.1:4010
# Sending wallets private keys
wallets:
  - PRIVATE_KEY
  - PRIVATE_KEY

Run the service:

./sender

Nats messages HTTP messages

---

Project

Dir	Description
build	Building artifacts, Docker files
cmd	Apps' entrypoint
internal	Apps' internals
pkg	Nats/HTTP messages, Protobuf schemes
scripts	Building scripts
vendor	Go vendoring

Transport

Services' primary transport is Nats server. Messages are serialized with Protobuf.
Nats scheme: .proto file contains message scheme, .go file contains Nats subject names.
Simple HTTP API now is supported as well.

Storage

Currently there is only MySQL storage implemented, but it's not a problem to replace it with whatever.
See DAO interfaces for specific service.

Building

Ensure you have Go 1.12 to build the project.
Protoc should be installed in order to generate protocol mappings for Nats networking.

Run once to check dependencies: make deps
Build apps:

make build     # build executables
make dockerize # make a Docker image

Makefile builds services for Linux/AMD64 by default.
Use TARGETS arg to change this behaviour. For instance:

make TARGETS="watcher/windows/amd64/ sender/windows/amd64/ testcli/windows/amd64"

Testing

Setup MySQL database, run Nats, run Mint services and then run go run cmd/testcli/main.go to interact with the services.

Code test

Packages unit tests:

make test

TODO

• Instrumenting (Prometheus)
• HTTP API
• More DB drivers