initial commit

04-variables-and-outputs/examples/README.md

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+# Variables
+
+## Variable block
+
+must define variable block
+
+```
+variable "var_name" {
+  type = string
+}
+```
+
+## Variable types
+- string
+- number
+- bool
+- list(<TYPE>)
+- set(<TYPE>)
+- map(<TYPE>)
+- object({<ATTR NAME> = <TYPE>, ... })
+- tuple([<TYPE>, ...])
+
+## Variable files
+`variables.tfvars` (or `<FILENAME>.auto.tfvars`) automatically applied 
+
+## Apply default
+`terraform apply`
+
+## Apply a different variable file
+`terraform apply -var-file=another-variable-file.tfvars`
+
+## Passing Variable via Prompt
+If value not specified, Terraform will prompt for value. (this is okay for testing... but don't depend on it since you should be automating things!)
+```
+  var.db_pass
+  password for database
+
+  Enter a value:
+```
+
+## Passing Variables via CLI
+`terraform apply -var="db_pass=$DB_PASS_ENV_VAR"`
+
+# Local Variables
+
+Allows you to store the value of expression for reuse but doesn't allow for passing in values 
+```
+locals {
+  extra_tag = "extra-tag"
+}
+```
+
+# Output Variables
+
+Allows you to output some value  (which might not be known ahead of time).
+
+For example it might be useful to know the IP address of a VM that was created:
+
+```
+output "instance_ip_addr" {
+  value = aws_instance.instance.private_ip
+}
+```
+
+Sample output:
+```
+db_instance_addr = "terraform-20210504182745335900000001.cr2ub9wmsmpg.us-east-1.rds.amazonaws.com"
+instance_ip_addr = "172.31.24.95"
+```
+
+Will be output after `terraform apply` or `terraform output`

04-variables-and-outputs/examples/another-variable-file.tfvars

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+instance_name = "hello-world-2"

04-variables-and-outputs/examples/main.tf

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+terraform {
+  backend "s3" {
+    bucket         = "devops-directive-tf-state"
+    key            = "04-variables-and-outputs/examples/terraform.tfstate"
+    region         = "us-east-1"
+    dynamodb_table = "terraform-state-locking"
+    encrypt        = true
+  }
+
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 3.0"
+    }
+  }
+}
+
+provider "aws" {
+  region = "us-east-1"
+}
+
+locals {
+  extra_tag = "extra-tag"
+}
+
+resource "aws_instance" "instance" {
+  ami           = var.ami
+  instance_type = var.instance_type
+
+  tags = {
+    Name     = var.instance_name
+    ExtraTag = local.extra_tag
+  }
+}
+
+resource "aws_db_instance" "db_instance" {
+  allocated_storage   = 20
+  storage_type        = "gp2"
+  engine              = "postgres"
+  engine_version      = "12.4"
+  instance_class      = "db.t2.micro"
+  name                = "mydb"
+  username            = var.db_user
+  password            = var.db_pass
+  skip_final_snapshot = true
+}
+

04-variables-and-outputs/examples/outputs.tf

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+output "instance_ip_addr" {
+  value = aws_instance.instance.private_ip
+}
+
+output "db_instance_addr" {
+  value = aws_db_instance.db_instance.address
+}

04-variables-and-outputs/examples/terraform.tfvars

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+instance_name = "hello-world"
+ami = "ami-011899242bb902164" # Ubuntu 20.04 LTS // us-east-1
+instance_type = "t2.micro"

04-variables-and-outputs/examples/variables.tf

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+# should specify optional vs required
+
+variable "instance_name" {
+  description = "Name of ec2 instance"
+  type        = string
+}
+
+variable "ami" {
+  description = "Amazon machine image to use for ec2 instance"
+  type        = string
+  default     = "ami-011899242bb902164" # Ubuntu 20.04 LTS // us-east-1
+}
+
+variable "instance_type" {
+  description = "ec2 instance type"
+  type        = string
+  default     = "t2.micro"
+}
+
+variable "db_user" {
+  description = "username for database"
+  type        = string
+  default     = "foo"
+}
+
+variable "db_pass" {
+  description = "password for database"
+  type        = string
+  sensitive   = true
+}

04-variables-and-outputs/web-app/main.tf

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+terraform {
+  # Assumes s3 bucket and dynamo DB table already set up
+  # See /code/03-basics/aws-backend
+  backend "s3" {
+    bucket         = "devops-directive-tf-state"
+    key            = "04-variables-and-outputs/web-app/terraform.tfstate"
+    region         = "us-east-1"
+    dynamodb_table = "terraform-state-locking"
+    encrypt        = true
+  }
+
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 3.0"
+    }
+  }
+}
+
+
+provider "aws" {
+  region = var.region
+}
+
+resource "aws_instance" "instance_1" {
+  ami             = var.ami
+  instance_type   = var.instance_type
+  security_groups = [aws_security_group.instances.name]
+  user_data       = <<-EOF
+              #!/bin/bash
+              echo "Hello, World 1" > index.html
+              python3 -m http.server 8080 &
+              EOF
+}
+
+resource "aws_instance" "instance_2" {
+  ami             = var.ami
+  instance_type   = var.instance_type
+  security_groups = [aws_security_group.instances.name]
+  user_data       = <<-EOF
+              #!/bin/bash
+              echo "Hello, World 2" > index.html
+              python3 -m http.server 8080 &
+              EOF
+}
+
+resource "aws_s3_bucket" "bucket" {
+  bucket        = var.bucket_name
+  force_destroy = true
+  versioning {
+    enabled = true
+  }
+
+  server_side_encryption_configuration {
+    rule {
+      apply_server_side_encryption_by_default {
+        sse_algorithm = "AES256"
+      }
+    }
+  }
+}
+
+data "aws_vpc" "default_vpc" {
+  default = true
+}
+
+data "aws_subnet_ids" "default_subnet" {
+  vpc_id = data.aws_vpc.default_vpc.id
+}
+
+resource "aws_security_group" "instances" {
+  name = "instance-security-group"
+}
+
+resource "aws_security_group_rule" "allow_http_inbound" {
+  type              = "ingress"
+  security_group_id = aws_security_group.instances.id
+
+  from_port   = 8080
+  to_port     = 8080
+  protocol    = "tcp"
+  cidr_blocks = ["0.0.0.0/0"]
+}
+
+resource "aws_lb_listener" "http" {
+  load_balancer_arn = aws_lb.load_balancer.arn
+
+  port = 80
+
+  protocol = "HTTP"
+
+  # By default, return a simple 404 page
+  default_action {
+    type = "fixed-response"
+
+    fixed_response {
+      content_type = "text/plain"
+      message_body = "404: page not found"
+      status_code  = 404
+    }
+  }
+}
+
+resource "aws_lb_target_group" "instances" {
+  name     = "example-target-group"
+  port     = 8080
+  protocol = "HTTP"
+  vpc_id   = data.aws_vpc.default_vpc.id
+
+  health_check {
+    path                = "/"
+    protocol            = "HTTP"
+    matcher             = "200"
+    interval            = 15
+    timeout             = 3
+    healthy_threshold   = 2
+    unhealthy_threshold = 2
+  }
+}
+
+resource "aws_lb_target_group_attachment" "instance_1" {
+  target_group_arn = aws_lb_target_group.instances.arn
+  target_id        = aws_instance.instance_1.id
+  port             = 8080
+}
+
+resource "aws_lb_target_group_attachment" "instance_2" {
+  target_group_arn = aws_lb_target_group.instances.arn
+  target_id        = aws_instance.instance_2.id
+  port             = 8080
+}
+
+resource "aws_lb_listener_rule" "instances" {
+  listener_arn = aws_lb_listener.http.arn
+  priority     = 100
+
+  condition {
+    path_pattern {
+      values = ["*"]
+    }
+  }
+
+  action {
+    type             = "forward"
+    target_group_arn = aws_lb_target_group.instances.arn
+  }
+}
+
+
+resource "aws_security_group" "alb" {
+  name = "alb-security-group"
+}
+
+resource "aws_security_group_rule" "allow_alb_http_inbound" {
+  type              = "ingress"
+  security_group_id = aws_security_group.alb.id
+
+  from_port   = 80
+  to_port     = 80
+  protocol    = "tcp"
+  cidr_blocks = ["0.0.0.0/0"]
+
+}
+
+resource "aws_security_group_rule" "allow_alb_all_outbound" {
+  type              = "egress"
+  security_group_id = aws_security_group.alb.id
+
+  from_port   = 0
+  to_port     = 0
+  protocol    = "-1"
+  cidr_blocks = ["0.0.0.0/0"]
+
+}
+
+
+resource "aws_lb" "load_balancer" {
+  name               = "web-app-lb"
+  load_balancer_type = "application"
+  subnets            = data.aws_subnet_ids.default_subnet.ids
+  security_groups    = [aws_security_group.alb.id]
+
+}
+
+resource "aws_route53_zone" "primary" {
+  name = var.domain
+}
+
+resource "aws_route53_record" "root" {
+  zone_id = aws_route53_zone.primary.zone_id
+  name    = var.domain
+  type    = "A"
+
+  alias {
+    name                   = aws_lb.load_balancer.dns_name
+    zone_id                = aws_lb.load_balancer.zone_id
+    evaluate_target_health = true
+  }
+}
+
+resource "aws_db_instance" "db_instance" {
+  allocated_storage   = 20
+  storage_type        = "standard"
+  engine              = "postgres"
+  engine_version      = "12.5"
+  instance_class      = "db.t2.micro"
+  name                = var.db_name
+  username            = var.db_user
+  password            = var.db_pass
+  skip_final_snapshot = true
+}

04-variables-and-outputs/web-app/outputs.tf

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+output "instance_1_ip_addr" {
+  value = aws_instance.instance_1.public_ip
+}
+
+output "instance_2_ip_addr" {
+  value = aws_instance.instance_2.public_ip
+}
+
+output "db_instance_addr" {
+  value = aws_db_instance.db_instance.address
+}

04-variables-and-outputs/web-app/terraform.tfvars

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+bucket_name = "devops-directive-web-app-data"
+domain = "mysuperawesomesite.com"
+db_name = "mydb"
+db_user = "foo"
+# db_pass = "foobarbaz"

04-variables-and-outputs/web-app/variables.tf

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+# General Variables
+
+variable "region" {
+  description = "Default region for provider"
+  type        = string
+  default     = "us-east-1"
+}
+
+# EC2 Variables
+
+variable "ami" {
+  description = "Amazon machine image to use for ec2 instance"
+  type        = string
+  default     = "ami-011899242bb902164" # Ubuntu 20.04 LTS // us-east-1
+}
+
+variable "instance_type" {
+  description = "ec2 instance type"
+  type        = string
+  default     = "t2.micro"
+}
+
+# S3 Variables
+
+variable "bucket_name" {
+  description = "name of s3 bucket for app data"
+  type        = string
+}
+
+# Route 53 Variables
+
+variable "domain" {
+  description = "Domain for website"
+  type        = string
+}
+
+# RDS Variables
+
+variable "db_name" {
+  description = "Name of DB"
+  type        = string
+}
+
+variable "db_user" {
+  description = "Username for DB"
+  type        = string
+}
+
+variable "db_pass" {
+  description = "Password for DB"
+  type        = string
+  sensitive   = true
+}
+
+