DB Subnet Group doesn't meet availability zone coverage requirement. Please add subnets to cover at least 2 availability zones. Current coverage: 1

Question

I have created two subnets for rds but still, I am getting error DB Subnet Group doesn't meet the availability zone coverage requirement. Please add subnets to cover at least 2 availability zones. Current coverage: 1, As I can check my both subnets, even all of my subnets are getting created in the same availability zone. Can you Please guide me

resource "aws_db_subnet_group" "rdssubnet" {
  name       = "database subnet"
  subnet_ids = ["${aws_subnet.rds_subnet.id}","${aws_subnet.rds_subnet1.id}"]
}


#provision the database
resource "aws_db_instance" "database" {
  identifier             = "database"
  instance_class         = var.db_instance_type
  allocated_storage      = var.db_size
  engine                 = "mysql"
  multi_az               =  false
  name                   = "Database "
  password               = var.rds_password
  username               = var.rds_user
  engine_version         = "5.7.00"
  skip_final_snapshot    = true
  db_subnet_group_name   = aws_db_subnet_group.rdssubnet.name
  vpc_security_group_ids = [aws_security_group.rds.id]

Answer 1

When you create your aws_subnet, you have to specify AZs where to place them. There is a special attribute for that called availability_zone. For example:

resource "aws_subnet" "rds_subnet" {
  vpc_id     = aws_vpc.main.id
  cidr_block = "10.0.1.0/24"
  availability_zone = "us-east-1a"
}

resource "aws_subnet" "rds_subnet1" {
  vpc_id     = aws_vpc.main.id
  cidr_block = "10.0.2.0/24"
  availability_zone = "us-east-1b"
}