AWS Fargate can't resolve Private DNS Route 53 - amazon-web-services

Question

I have a Cloudformation that creates a AWS Fargate on ECS Cluster, in this way:
TaskDefinition:
Type: 'AWS::ECS::TaskDefinition'
Properties:
RequiresCompatibilities:
- FARGATE
Cpu: !Ref ContainerCpu
Memory: !Ref ContainerMemory
ExecutionRoleArn: !Ref ExecutionRole
TaskRoleArn: !Ref ExecutionRole
ContainerDefinitions:
- Name: !Sub ${ContainerName}
Image: 'image-url-here'
Essential: true
HealthCheck:
Command: ["CMD-SHELL", "test -f hc.log"]
LogConfiguration:
LogDriver: awslogs
Options:
awslogs-region: !Sub '${AWS::Region}'
awslogs-group: !Sub '${FeatureName}-${MicroServiceName}'
awslogs-stream-prefix: !Ref MicroServiceName
Family: !Sub 'family-${FeatureName}-${MicroServiceName}'
NetworkMode: awsvpc
DependsOn: CloudWatchLogGroup
ExecutionRole:
Type: AWS::IAM::Role
Properties:
RoleName: !Join ['', [!Ref MicroServiceName, ExecutionRole]]
AssumeRolePolicyDocument:
Statement:
- Effect: Allow
Principal:
Service: ecs-tasks.amazonaws.com
Action: 'sts:AssumeRole'
ManagedPolicyArns:
- 'arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy'
My ECS Task Fargate need to access a API that is running in a EC2 , so I created a DNS Private Hosted Zone with the following address: api.localaccount. But when I try to access this API from my Fargate i got the following error:
System.Net.Http.HttpRequestException: Name or service not known
I know that this error is because my AWS Fargate can't resolve DNS, but I don't know why. If I access this same DNS (api.localaccount) from EC2 everything works fine, so I think my DNS Route 53 is ok.

Answer 1

Based on the comments.
The issue was due to the use of a wrong link in the application. Thus, it was application-level problem, not ECS Farage issue.

Answer 2

To use private hosted zones, you must set the following Amazon VPC settings to true:
enableDnsHostnames
enableDnsSupport


Answer 3

ECS Service by default can't resolve DNS. You have to explicitly enable it during service creation part. Once you enable it, you have option to select the Namespace and record type.
*All of this should be done after setting up Route53 and VPC config. In this case you've already done those.