ab.sh

ab -n 10000 -c 100 -T text/json -p ping.json http://127.0.0.1:5000/ping/

httpie.sh

http -j post localhost:5000/ping/ pong=pong

mojolicious-ping.pl

use Mojolicious::Lite;

app->log->level('error');

post '/ping' => sub {
  my ($c) = @_;
  my $json = $c->req->json;
  my $pong = $json ? $json->{pong} : 'ping';
  $c->render(json => { pong => $pong });
};

app->start;

ping.json

{"pong":"pong"}

plack-ping.pl

use JSON::XS;
use Plack::App::URLMap;
use Plack::Request;

my $ping_app = sub {
  my ($env) = @_;
  my $req = Plack::Request->new($env);
  my $content = $req->content;
  my $json = decode_json $content if $content;
  my $pong = $json ? $json->{pong} : 'ping';

  my $res = $req->new_response(200);
  $res->content_type('text/json');
  $res->body(encode_json { pong => $pong });
  $res->finalize;
};

my $urlmap = Plack::App::URLMap->new;
$urlmap->map('/ping' => $ping_app);
my $app = $urlmap->to_app;

$app;