Problems in the connection process between moodle and rds in aws eks - amazon-rds

Question

I'm using terraform to distribute eks, rds, and kubernetes and try to run moodle. The image for moodle is using bitnami/moodle:latest.
Both eks and rds work on the same vpc, and the are generated very well. However, when I try to distribute moodle in kubernetes with rds, I experience problems with not accessing the database. What's the problem with connecting databases?
root#master:~/moodle_deploy# kubectl get pod
NAME READY STATUS RESTARTS AGE
moodle-54f477b7f8-nh98h 0/1 CrashLoopBackOff 15 70m
moodle-54f477b7f8-rhzzj 0/1 CrashLoopBackOff 15 70m
root#master:~/moodle_deploy# kubectl logs moodle-54f477b7f8-rhzzj
moodle 06:33:12.43
moodle 06:33:12.43 Welcome to the Bitnami moodle container
moodle 06:33:12.43 Subscribe to project updates by watching https://github.com/bitnami/containers
moodle 06:33:12.43 Submit issues and feature requests at https://github.com/bitnami/containers/issuesmoodle 06:33:12.43
moodle 06:33:12.44 INFO ==> ** Starting Moodle setup **
realpath: /bitnami/apache/conf: No such file or directory
moodle 06:33:12.46 INFO ==> Configuring Apache ServerTokens directive
moodle 06:33:12.49 INFO ==> Configuring PHP options
moodle 06:33:12.49 INFO ==> Setting PHP expose_php option
moodle 06:33:12.51 INFO ==> Validating settings in MYSQL_CLIENT_* env vars
moodle 06:33:12.53 INFO ==> Validating settings in POSTGRESQL_CLIENT_* env vars
moodle 06:33:12.69 INFO ==> Ensuring Moodle directories exist
moodle 06:33:12.78 INFO ==> Trying to connect to the database server
moodle 06:34:12.90 ERROR ==> Could not connect to the database
root#master:~/moodle_deploy# kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
moodle-pv-claim Bound pvc-eefbb1d9-a6fd-4cf5-b044-159145798114 1Gi RWO gp2 59m
root#master:~/moodle_deploy# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-eefbb1d9-a6fd-4cf5-b044-159145798114 1Gi RWO Delete Bound default/moodle-pv-claim gp2 59m
These are the code that defined rds and kubernetes among the terraform files I distributed
//SECURITY GROUP
resource "aws_security_group" "secgrp-rds" {
name = "secgrp-rdis"
description = "Allow MySQL Port"
vpc_id = module.vpc.vpc_id
ingress {
description = "Allowing Connection for mysql"
from_port = 3306
to_port = 3306
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
}
ingress {
description = "Allowing Connection for SSH"
from_port = 22
to_port = 22
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"]
}
}
resource "aws_db_subnet_group" "sub_ids" {
name = "main"
subnet_ids = module.vpc.private_subnets
tags = {
Name = "DB subnet group"
}
}
//RDS INSTANCE
resource "aws_db_instance" "rds" {
depends_on=[aws_security_group.secgrp-rds]
engine = "mysql"
engine_version = "5.7"
instance_class = "db.t2.micro"
allocated_storage = 20
storage_type = "gp2"
name = "moodledb"
identifier = "moodledb"
username = "root"
password = "test12345"
parameter_group_name = "default.mysql5.7"
#publicly_accessible = true
skip_final_snapshot = true
apply_immediately = true
iam_database_authentication_enabled = true
db_subnet_group_name = aws_db_subnet_group.sub_ids.id
vpc_security_group_ids = [aws_security_group.secgrp-rds.id]
}
//CREATE DEPLOYMENT - provide rds environment variables
resource "kubernetes_deployment" "moodle" {
depends_on = [aws_db_instance.rds]
metadata {
name = "moodle"
labels = {
App = "moodle"
}
}
spec {
replicas = 2
selector {
match_labels = {
App = "moodle"
}
}
template {
metadata {
labels = {
App = "moodle"
}
}
spec {
container {
image = "bitnami/moodle:latest"
name = "moodle"
env{
name = "MOODLE_DATABASE_TYPE"
value = "mysqli"
}
env{
name = "MOODLE_DATABASE_HOST"
value = aws_db_instance.rds.endpoint
}
env{
name = "MOODLE_DATABASE_USER"
value = aws_db_instance.rds.username
}
env{
name = "MOODLE_DATABASE_PASSWORD"
value = aws_db_instance.rds.password
}
env{
name = "MOODLE_DATABASE_NAME"
value = aws_db_instance.rds.db_name
}
port {
container_port = 8080
}
volume_mount {
name = "moodle-ps"
mount_path = "/opt/bitnami/apache2/htdocs/"
}
resources {
limits= {
cpu = "0.5"
memory = "512Mi"
}
requests= {
cpu = "250m"
memory = "50Mi"
}
}
}
volume {
name = "moodle-ps"
persistent_volume_claim {
claim_name = "moodle-pv-claim"
}
}
}
}
}
}
resource "kubernetes_service" "moodle" {
depends_on = [kubernetes_deployment.moodle]
metadata {
name = "moodle"
}
spec {
port {
port = 80
target_port = 8080
}
type = "LoadBalancer"
}
}
resource "kubernetes_storage_class" "kubeSC" {
metadata {
name = "kubese"
}
storage_provisioner = "kubernetes.io/aws-ebs"
reclaim_policy = "Retain"
parameters = {
type = "gp2"
}
}
resource "kubernetes_persistent_volume_claim" "pvc" {
depends_on=[kubernetes_storage_class.kubeSC]
metadata {
name = "moodle-pv-claim"
labels = {
"app" = "moodle"
}
}
spec {
access_modes = ["ReadWriteOnce"]
resources {
requests = {
storage = "1Gi"
}
}
}
}