Unable to connect GCP SQL Instance from GKE cluster

I have created a vpc-native cluster and I am trying to connect from a pod inside the cluster to a postgres SQL instance with a private IP.

I am testing using a basic telnet 5432 command.

The connection works fine when I try it from a GCE instance that is in the same VPC. All connectivity tests in GCP are giving me green light so it seems to be a k8s issue.

Here is my cluster:

gcloud container clusters create alex-test \                                                            
    --network=factory-vpc \
    --region=europe-west1 \
    --enable-ip-alias \
    --subnetwork=europe-west1-factory-subnet \
    --cluster-ipv4-cidr="/16" \
    --services-ipv4-cidr="/20"

Here is how I am testing the connectivity:

kubectl run -it --rm --restart=Never busybox --image=gcr.io/google-containers/busybox sh
telnet <private ip> 5432

Here is my network config in terraform:

resource "google_compute_network" "factory" {
  name                    = "factory-vpc"
  auto_create_subnetworks = false

  depends_on = [google_project_service.compute]
}

resource "google_compute_subnetwork" "factory_subnet" {
  name                     = "${var.region}-factory-subnet"
  ip_cidr_range            = "10.0.0.0/16"
  region                   = var.region
  network                  = google_compute_network.factory.self_link
  private_ip_google_access = true

  secondary_ip_range {
    ip_cidr_range = "10.2.0.0/16"
    range_name    = "pods"
  }

  secondary_ip_range {
    ip_cidr_range = "10.3.0.0/16"
    range_name    = "services"
  }
}

resource "google_compute_global_address" "gitlab_google_private_peering" {
  provider      = google-beta
  name          = "gitlab-gcp-private"
  address_type  = "INTERNAL"
  purpose       = "VPC_PEERING"
  network       = google_compute_network.factory.self_link
  prefix_length = 16
}

resource "google_service_networking_connection" "gitlab_google_private_peering" {
  provider                = google-beta
  network                 = google_compute_network.factory.self_link
  service                 = "servicenetworking.googleapis.com"
  reserved_peering_ranges = [google_compute_global_address.gitlab_google_private_peering.name]
}

I have already checked the following documentation and articles, but nothing helps:

• Vpc native cluster
• Connecting to SQL from GKE
• Another issue
• Another issue

Any help is greatly appreciated !

Please make sure and check if you can communicate with your instance, hostname and declared IP address. If you are ok with that make sure also that you are in the same region.

I found this link this might help you. Here is also how to set up a cluster with shared VPC.