AWS EC2 instance not joining ECS cluster - amazon-web-services

Question

I am quite desperate with an issue very similar to the one described into this thread.
https://github.com/OpenDroneMap/opendronemap-ecs/issues/14#issuecomment-432004023
When I attach the network interface to my EC2 instance, so that my custom VPC is used instead of the default one, the EC2 instance no longer joins the ECS cluster.
This is my terraform definition.
provider "aws" {}
resource "aws_vpc" "main" {
cidr_block = "10.0.0.0/16"
enable_dns_support = true
enable_dns_hostnames = true
assign_generated_ipv6_cidr_block = true
}
resource "aws_internet_gateway" "main" {
vpc_id = aws_vpc.main.id
}
resource "aws_subnet" "main" {
vpc_id = aws_vpc.main.id
cidr_block = "10.0.0.0/16"
availability_zone = "us-west-2a"
map_public_ip_on_launch = true
}
resource "aws_route_table" "main" {
vpc_id = aws_vpc.main.id
}
resource "aws_route_table_association" "rta1" {
subnet_id = aws_subnet.main.id
route_table_id = aws_route_table.main.id
}
resource "aws_route_table_association" "rta2" {
gateway_id = aws_internet_gateway.main.id
route_table_id = aws_route_table.main.id
}
resource "aws_security_group" "sg-jenkins" {
name = "sg_jenkins"
description = "Allow inbound traffic for Jenkins instance"
vpc_id = aws_vpc.main.id
ingress = [
{
description = "inbound all"
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
self = null
prefix_list_ids = null
security_groups = null
}
]
egress = [
{
description = "outbound all"
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
self = null
prefix_list_ids = null
security_groups = null
}
]
}
resource "aws_network_interface" "main" {
subnet_id = aws_subnet.main.id
security_groups = [aws_security_group.sg-jenkins.id]
}
resource "aws_instance" "ec2_instance" {
ami = "ami-07764a7d8502d36a2"
instance_type = "t2.micro"
iam_instance_profile = "ecsInstanceRole"
key_name = "fran"
network_interface {
device_index = 0
network_interface_id = aws_network_interface.main.id
}
user_data = <<EOF
#!/bin/bash
echo ECS_CLUSTER=cluster >> /etc/ecs/ecs.config
EOF
depends_on = [aws_internet_gateway.main]
}
### Task definition
resource "aws_ecs_task_definition" "jenkins-task" {
family = "namespace"
container_definitions = jsonencode([
{
name = "jenkins"
image = "cnservices/jenkins-master"
cpu = 10
memory = 512
essential = true
portMappings = [
{
containerPort = 8080
hostPort = 8080
}
]
}
])
# network_mode = "awsvpc"
volume {
name = "service-storage"
host_path = "/ecs/service-storage"
}
placement_constraints {
type = "memberOf"
expression = "attribute:ecs.availability-zone in [us-west-2a]"
}
}
### Cluster
resource "aws_ecs_cluster" "cluster" {
name = "cluster"
setting {
name = "containerInsights"
value = "enabled"
}
}
### Service
resource "aws_ecs_service" "jenkins-service" {
name = "jenkins-service"
cluster = aws_ecs_cluster.cluster.id
task_definition = aws_ecs_task_definition.jenkins-task.arn
desired_count = 1
# iam_role = aws_iam_role.foo.arn
# depends_on = [aws_iam_role_policy.foo]
# network_configuration {
# security_groups = [aws_security_group.sg-jenkins.id]
# subnets = [aws_subnet.main.id]
# }
ordered_placement_strategy {
type = "binpack"
field = "cpu"
}
placement_constraints {
type = "memberOf"
expression = "attribute:ecs.availability-zone in [us-west-2a]"
}
}

Answer 1

You haven't created a route to your IGW. Thus your instance can't connect to the ECS service to register with your cluster. So remove rta2 and add a route:
# not needed. to be removed.
# resource "aws_route_table_association" "rta2" {
# gateway_id = aws_internet_gateway.main.id
# route_table_id = aws_route_table.main.id
# }
# add a missing route to the IGW
resource "aws_route" "r" {
route_table_id = aws_route_table.main.id
gateway_id = aws_internet_gateway.main.id
destination_cidr_block = "0.0.0.0/0"
}