Terraform rejecting JSON template_file - terraform

Question

The following ECS task definition is being rejected by Terraform during a plan. JSON validates and using the inline container_definitions works fine.
I've Googled and read some commentary that states TF has an issue with JSON objects, mostly related to nesting. I can get around this by placing the JSON into the container_definition directly in the resource block for the task definition, but I would prefer to stick it in a template file.
Error: Error running plan: 1 error(s) occurred:
* module.sonarqube.aws_ecs_task_definition.task: ECS Task Definition container_definitions is invalid: Error decoding JSON: json: cannot unmarshal string into Go struct field ContainerDefinition.Memory of type int64
JSON Document referenced in template_file:
{
"name": "sonarqube",
"image": "sonarqube:7.5-community",
"memory": "2048",
"logConfiguration": {
"logDriver": "awslogs",
"options": {
"awslogs-group": "${log-group}",
"awslogs-region": "${region}",
"awslogs-stream-prefix": "ecs"
}
},
"portMappings": {
"hostPort": "9000",
"protocol": "tcp",
"containerPort": "9000"
},
"environment": [
{
"name": "sonar.jdbc.password",
"value": "${password}"
},
{
"name": "sonar.jdbc.url",
"value": "${url}/${extra_url}"
},
{
"name": "sonar.jdbc.username",
"value": "${username}"
}
]
}
Relevant TF Blocks:
data "template_file" "task-def" {
template = "${file("${path.module}/task-def.json")}"
vars = {
log-group = "/ecs/${var.cluster_name}-${var.name}"
region = "${var.region}"
url = "jdbc:postgresql://${var.rds_url}${var.extra_url}"
username = "${var.username}"
password = "${var.password}"
}
}
resource "aws_ecs_task_definition" "task" {
family = "${var.name}"
network_mode = "bridge"
cpu = "1024"
memory = "2048"
execution_role_arn = "${var.ecs-exec-role}"
container_definitions = "${data.template_file.task-def.rendered}"
}
```

Answer 1

Terraform expects Json in a bit dirrerent format. After you fix this it will work:
Memory size and port numbers should be integer, not string
Terraform wants "array with oblects", not a JSON "object"
Variable $extra_url was not imported in template_file.task-def
Fixed version of task-def.json, tested on terraform v0.11.13 and provider.aws v2.9.0:
[
{
"name": "sonarqube"
},
{
"image": "sonarqube:7.5-community"
},
{
"memory": 2048
},
{
"logConfiguration": {
"logDriver": "awslogs",
"options": {
"awslogs-group": "tyu",
"awslogs-region": "tyu",
"awslogs-stream-prefix": "ecs"
}
}
},
{
"portMappings": [
{
"hostPort": 9000
},
{
"protocol": "tcp"
},
{
"containerPort": 9000
}
]
},
{
"environment": [
{
"name": "sonar.jdbc.password",
"value": "${password}"
},
{
"name": "sonar.jdbc.url",
"value": "${url}/${extra_url}"
},
{
"name": "sonar.jdbc.username",
"value": "${username}"
}
]
}
]
Fixed version of template_file.task-def:
data "template_file" "task-def" {
template = "${file("${path.module}/task-def.json")}"
vars = {
log-group = "/ecs/${var.cluster_name}-${var.name}"
region = "${var.region}"
url = "jdbc:postgresql://${var.rds_url}${var.extra_url}"
username = "${var.username}"
password = "${var.password}"
extra_url = "${var.extra_url}"
}
}