AWS ECS Fargate Container Failure - amazon-web-services

Question

Issue:
I am deploying ECS Fargate using Terraform. When I deploy everything goes great, but then the task fails saying "Essential container in task exited". I expanded the task and it says exit code 134. I have tried upping the CPU and Memory, and triple checking the files, but I can't figure out what is wrong. Anyone have any advice?
Files:
fargate.tf
resource "aws_ecs_task_definition" "backend_task" {
family = "backend_example_app_family"
// Fargate is a type of ECS that requires awsvpc network_mode
requires_compatibilities = ["FARGATE"]
network_mode = "awsvpc"
// Valid sizes are shown here: https://aws.amazon.com/fargate/pricing/
memory = "1024"
cpu = "512"
// Fargate requires task definitions to have an execution role ARN to support ECR images
execution_role_arn = "${aws_iam_role.ecs_role.arn}"
container_definitions = <<EOT
[
{
"name": "example_app_container",
"image": "250531645249.dkr.ecr.us-east-1.amazonaws.com/ecr_example_repo:latest",
"memory": 512,
"essential": true,
"portMappings": [
{
"containerPort": 3000,
"hostPort": 3000
}
]
}
]
EOT
}
resource "aws_ecs_cluster" "backend_cluster" {
name = "backend_cluster_example_app"
}
resource "aws_ecs_service" "backend_service" {
name = "backend_service"
cluster = "${aws_ecs_cluster.backend_cluster.id}"
task_definition = "${aws_ecs_task_definition.backend_task.arn}"
launch_type = "FARGATE"
desired_count = 1
network_configuration {
subnets = ["${aws_subnet.public_a.id}", "${aws_subnet.public_b.id}"]
security_groups = ["${aws_security_group.security_group_example_app.id}"]
assign_public_ip = true
}
}
iam.tf
resource "aws_iam_role" "ecs_role" {
name = "ecs_role_example_app"
assume_role_policy = <<POLICY
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "",
"Effect": "Allow",
"Principal": {
"Service": "ecs-tasks.amazonaws.com"
},
"Action": "sts:AssumeRole"
}
]
}
POLICY
}
resource "aws_iam_role_policy_attachment" "ecs_policy_attachment" {
role = "${aws_iam_role.ecs_role.name}"
// This policy adds logging + ecr permissions
policy_arn = "arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy"
}
network.tf
resource "aws_vpc" "vpc_example_app" {
cidr_block = "10.0.0.0/16"
enable_dns_hostnames = true
enable_dns_support = true
}
resource "aws_subnet" "public_a" {
vpc_id = "${aws_vpc.vpc_example_app.id}"
cidr_block = "10.0.1.0/24"
availability_zone = "us-east-1a"
}
resource "aws_subnet" "public_b" {
vpc_id = "${aws_vpc.vpc_example_app.id}"
cidr_block = "10.0.2.0/24"
availability_zone = "us-east-1b"
}
resource "aws_internet_gateway" "internet_gateway" {
vpc_id = "${aws_vpc.vpc_example_app.id}"
}
resource "aws_route" "internet_access" {
route_table_id = "${aws_vpc.vpc_example_app.main_route_table_id}"
destination_cidr_block = "0.0.0.0/0"
gateway_id = "${aws_internet_gateway.internet_gateway.id}"
}
resource "aws_security_group" "security_group_example_app" {
name = "security_group_example_app"
description = "Allow TLS inbound traffic on port 80 (http)"
vpc_id = "${aws_vpc.vpc_example_app.id}"
ingress {
from_port = 80
to_port = 4000
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
}
}