probable-garbanzo

"What a wonderful phrase!"

OK... maybe not as catchy as Hakuna Matata. But this is a little project to explore some concepts using Scala.

About the project

In order to enhance my knowledge of Scala, I am trying to implement a simple setup to find prime numbers, making use of different technologies including gRPC/protobuf.

Project structure

There are five main components to the project:

prime-number-server: a small server which can tell you the next prime number which is greater than an input integer.
proxy-service: a small server which acts as a proxy to prime-number-server, returning a stream (over HTTP 1.1) of primes up to a given limit.
protobuf: protobuf contract for gRPC communication between the two servers
Integration tests: some simple test case scenarios, exercising the two servers together
Documentation: notes and documentation about the project

How to run

This is a Scala project, intended to be built with SBT. I assume you already have a working Scala development environment. If not, let me google that for you...

Run local servers

Both servers can be launched from sbt.

prime-number-server

# run prime-number-server with default options
sbt service/run

# configure available options
PRIME_SERVICE_HOST="service" \ # address to bind to
PRIME_SERVICE_PORT: 9876 \     # port to bind to
sbt service/run

proxy-service

# run proxy-service with default options
sbt proxy/run

With the default options, the proxy server can be reached at http://localhost:8080/prime/123 (replace 123 with the desired target).

# configure available options
PRIME_SERVICE_HOST="service" \ # address to contact prime-number-server
PRIME_SERVICE_PORT: 9876 \     # port to contact prime-number-server
PRIME_PROXY_HOST: "proxy" \    # address to bind to
PRIME_PROXY_PORT: 8765 \       # port to bind to
sbt proxy/run

Docker

It is possible to build docker images for both servers:

# just prime-number-server
sbt service/docker/publishLocal

# just proxy-service
sbt proxy/docker/publishLocal

# both components (shorthand for the two above commands)
sbt dockerBuild

Once the images have been built, they can be deployed to any Docker-based environment. A convenience Docker Compose config is provided in the project.

# bring up docker network...
docker-compose up

# ...and bring it down again
docker-compose down

As a convenient shorthand, an SBT task has been defined to build both containers and then bring up the docker network:

# build docker images and bring up docker network
sbt dockerRun

throup / probable-garbanzo