README.md

standard-deviation-service

How to run

service executable

go run cmd/main.go

or

go run cmd/main.go -reqs 15 -port 8081

container image

docker build --tag stddev .
docker run -v /etc/ssl/certs:/etc/ssl/certs --net host stddev

or

docker build --tag stddev .
docker run -v /etc/ssl/certs:/etc/ssl/certs --net host stddev -reqs 15 -port 8081

parameters

-reqs    number of requests per second
-port    port number

Task

Description

Create a simple REST service in Go supporting the following GET operation:

/random/mean?requests={r}&length={l}

which performs {r} concurrent requests to random.org API asking for {l} number of random integers.

For each of {r} requests, the service must calculate standard deviation of the drawn integers and additionally standard deviation of sum of all sets. Results must be presented in JSON format.

Example

GET /random/mean?requests=2&length=5

Response:

[
  {
     "stddev": 1,
     "data": [1, 2, 3, 4, 5]
  },
  {
     "stddev": 1,
     "data": [1, 2, 3, 4, 5]
  },
  { // stddev of sum
     "stddev": 1,
     "data": [1, 1, 2, 2, 3, 3, 4, 4, 5, 5]
  }
]

Requirements

1. Proper error handling when communicating with external service (timeouts, invalid statuses).
2. Usage of contexts.
3. Solution should be delivered as a git repository.
4. Provide a .Dockerfile that builds the image with the application.
5. Application should run flawlessly after running docker build ... & docker run ... commands.