count-task.pl

#!/usr/bin/perl
use strict;
use warnings;
use feature qw(:5.10);
use utf8;

use JSON::PP;
use HTTP::Tiny;


# 自分のタスクデータ取得
my ($own_cluster, $own_family, $own_version);
{
    my $response = HTTP::Tiny->new->get($ENV{ECS_CONTAINER_METADATA_URI_V4});
    die "failed to get ecs meta data" unless $response->{success};
    my $ecs_metadata = decode_json($response->{content});
    $own_cluster = $ecs_metadata->{Labels}->{"com.amazonaws.ecs.cluster"};
    $own_family  = $ecs_metadata->{Labels}->{"com.amazonaws.ecs.task-definition-family"};
    $own_version = $ecs_metadata->{Labels}->{"com.amazonaws.ecs.task-definition-version"};
}

# タスク一覧取得
my @tasks;
{
    my $result = `aws ecs list-tasks --cluster $own_cluster --family $own_family --desired-status RUNNING --output json`;
    my $tasks = decode_json($result);
    for (@{$tasks->{taskArns}}) {
        push(@tasks, $_);
    }
}

# 自分と同じバージョンのタスクを数える
my $task_count = 0;
for (@tasks) {
    my $result = `aws ecs describe-tasks --cluster $own_cluster --tasks $_ --output json`;
    my $task_info = decode_json($result);
    my $task_version = $task_info->{tasks}->[0]->{version};
    if ($task_version == $own_version) {
        $task_count++;
    }
}

say $task_count;