A Terraform Template for RDS

This module makes the following assumptions:

• You want your RDS instance in a VPC
• You have subnets in a VPC for two AZs
• Multi-AZ is optional.

• rds_instance_identifier - Custom name of the DB instance (NOT a database name)
• rds_is_multi_az - Defaults to false. Set to true for a multi-az instance.
• rds_storage_type - Defaults to standard (magnetic)
• rds_allocated_storage - The number of GBs to allocate. Input must be an integer, e.g. 10
• rds_engine_type - Engine type, such as mysql or postgres
• rds_engine_version - eg. 9.5.4 in case of postgres
• rds_instance_class - instance size, eg. db.t2.micro
• database_name - name of the dabatase
• database_user - user name (admin user)
• database_password - password - must be longer than 8 characters
• db_parameter_group - Defaults to mysql5.6, for postgres postgres9.5
• subnets - List of subnets IDs in a list form, eg. ["sb-1234567890", "sb-0987654321"]
• database_port - Database port (needed for a security group)
• publicly_accessible - Defaults to false
• private_cidr - CIDR for database security group, eg 10.0.0.0/16
• rds_vpc_id - VPC ID DB will be connected to
• allow_major_version_upgrade - Allow upgrading of major version of database (eg. from Postgres 9.5.x to Postgres 9.6.x), default: false
• auto_minor_version_upgrade - Automatically upgrade minor version of the DB (eg. from Postgres 9.5.3 to Postgres 9.5.4), default: true
• skip_final_snapshot - if true (default), DB won't be backed up before deletion
• copy_tags_to_snapshot - copy all tags from RDS database to snapshot (default true)
• backup_retention_period - backup retention period in days (default: 0), must be > 0 to enable backups
• backup_window - when to perform DB snapshot, default "22:00-03:00"; can't overlap with maintenance window
• pg_params - mapping of params you want to override AWS defaults in Parameter Group
• tags - A mapping of tags to assign to the resource.

• rds_instance_id - The ID of the RDS instance
• rds_instance_address - The Address of the RDS instance
• subnet_group_id - The ID of the Subnet Group

You can use these in your terraform template with the following steps.

1.) If you define subnets as follows (it's an example of one might do that)

resource "aws_subnet" "example" {
    count = "${length(var.availability_zones)}"

    vpc_id = "${aws_vpc.public.id}"
    cidr_block = "10.0.${count.index}.0/24"
    map_public_ip_on_launch = true

    availability_zone = "${var.region}${element(var.availability_zones, count.index)}"

    tags {
        Name = "${var.region}${element(var.availability_zones, count.index)}"
    }
}

From availability_zones and region variables defined as follows:

variable "region" {
    type = "string"
    default = "eu-central-1"
}

variable "availability_zones" {
    type = "list"
    default = ["a", "b"]
}

You will also need CIDR:

variable "private_cidr" {
    type = "string"
    default = "10.0.0.0/16"
}

2.) Adding a module resource to your template, e.g. main.tf

module "my_rds_instance" {
  source = "github.com/terraform-community-modules/tf_aws_rds"

    # RDS Instance Inputs
    rds_instance_identifier = "${var.rds_instance_identifier}"
    rds_allocated_storage = "${var.rds_allocated_storage}"
    rds_engine_type = "${var.rds_engine_type}"
    rds_instance_class = "${var.rds_instance_class}"
    rds_engine_version = "${var.rds_engine_version}"
    db_parameter_group = "${var.db_parameter_group}"

    database_name = "${var.database_name}"
    database_user = "${var.database_user}"
    database_password = "${var.database_password}"
    database_port = "${var.database_port}"

    # DB Subnet Group Inputs
    subnets = ["${aws_subnet.example.*.id}"] # see above
    rds_vpc_id = "${module.vpc}"
    private_cidr = "${var.private_cidr}"

    pg_params = [{
      name = "max_connections"
      apply_method = "pending-reboot"
      value = "200"
    }]

    tags {
        "Terraform" = "true"
        "Env" = "${terraform.env}"
    }
}

2.) Setting values for the following variables, either through terraform.tfvars or -var arguments on the CLI

• rds_instance_identifier
• rds_is_multi_az
• rds_storage_type
• rds_allocated_storage
• rds_engine_type
• rds_engine_version
• rds_instance_class
• database_name
• database_user
• database_password
• db_parameter_group
• subnets
• database_port
• publicly_accessible
• private_cidr
• rds_vpc_id
• allow_major_version_upgrade
• auto_minor_version_upgrade
• skip_final_snapshot
• copy_tags_to_snapshot
• backup_retention_period
• backup_window
• tags

Created and maintained by Brandon Burton ([email protected]).

• Grzegorz Adamowicz

Apache 2 Licensed. See LICENSE for full details.