nginx

In the real life, this microservice would work over HTTP. Let’s add nginx web server to our environment and make a similar demo. But how do we make Tarantool methods callable via REST API? We use nginx with Tarantool nginx upstream module and create one more Lua script (app.lua) that exports three of our game methods – add_pokemon(), map() and catch() – as REST endpoints of the nginx upstream module:

local game = require('pokemon')
box.cfg{listen=3301}
game:start()

-- add, map and catch functions exposed to REST API
function add(request, pokemon)
    return {
        result=game:add_pokemon(pokemon)
    }
end

function map(request)
    return {
        map=game:map()
    }
end

function catch(request, pid, player)
    local id = tonumber(pid)
    if id == nil then
        return {result=false}
    end
    return {
        result=game:catch(id, player)
    }
end

An easy way to configure and launch nginx would be to create a Docker container based on a Docker image with nginx and the upstream module already installed (see http/Dockerfile). We take a standard nginx.conf, where we define an upstream with our Tarantool backend running (this is another Docker container, see details below):

upstream tnt {
      server pserver:3301 max_fails=1 fail_timeout=60s;
      keepalive 250000;
}

and add some Tarantool-specific parameters (see descriptions in the upstream module’s README file):

server {
  server_name tnt_test;

  listen 80 default deferred reuseport so_keepalive=on backlog=65535;

  location = / {
      root /usr/local/nginx/html;
  }

  location /api {
    # answers check infinity timeout
    tnt_read_timeout 60m;
    if ( $request_method = GET ) {
       tnt_method "map";
    }
    tnt_http_rest_methods get;
    tnt_http_methods all;
    tnt_multireturn_skip_count 2;
    tnt_pure_result on;
    tnt_pass_http_request on parse_args;
    tnt_pass tnt;
  }
}

Likewise, we put Tarantool server and all our game logic in a second Docker container based on the official Tarantool 1.9 image (see src/Dockerfile) and set the container’s default command to tarantool app.lua. This is the backend.

Version:

nginx