TER-412 regenerate platform metadata on lint

change the behavior of lint command to always regenerate the
platform metadata file (terrarium.yaml) on every lint command execution

This implies that the manual changes in platform metadata file are not
acceptable now.
this also impacts the behavior of terrarium generate command such that
it doesn't respect the manual changes in the platform metadata file

This also impacts the example platform since it was not
actually implementing the dependencies and it was only
added to the metadata file to bypass the errors.
Therefore this change also has updates the the `example/platform`
such that now it implements each dependency in terraform and doesn't
have manually adjusted metadata.
Although the `example/platform` contains working mock implementation
such that it can be used to test the t8 lint & generate command and can
also run terraform plan and apply successfully but it'll generate
random mock values for output instead of actually provisioning resources
on cloud.

examples/platform/component_job.tf

@@ -0,0 +1,39 @@
+module "job_queue_runner" {
+  source = "./mock-modules/k8s-service"
+
+  for_each = local.tr_component_job_queue
+
+  name = "queue_watcher_${each.key}"
+  cluster_id = module.k8s_cluster.cluster_id
+}
+
+module "job_scheduled_runner" {
+  source = "./mock-modules/k8s-service"
+
+  for_each = local.tr_component_job_scheduled
+
+  name = "scheduler_${each.key}"
+  cluster_id = module.k8s_cluster.cluster_id
+}
+
+# A job that performs tasks in the queue.
+# @title: Queue Job
+module "tr_component_job_queue" {
+  source = "./mock-modules/pubsub-queue"
+
+  for_each = local.tr_component_job_queue
+
+  event_receiver_url = module.job_queue_runner[each.key].host
+  name = each.key
+}
+
+# A job that is run at scheduled intervals.
+# @title: Scheduled Job
+module "tr_component_job_scheduled" {
+  source = "./mock-modules/cloud-scheduler"
+
+  for_each = local.tr_component_job_scheduled
+
+  event_receiver_url = module.job_scheduled_runner[each.key].host
+  name = each.key
+}

examples/platform/component_postgres.tf

@@ -1,7 +1,7 @@
 # A relational database management system using SQL.
 # @title: PostgreSQL Database
 module "tr_component_postgres" {
-  source = "terraform-aws-modules/rds/aws"
+  source = "./mock-modules/rds"
 
   for_each = local.tr_component_postgres
 
@@ -18,7 +18,7 @@ module "tr_component_postgres" {
 }
 
 module "postgres_security_group" {
-  source = "terraform-aws-modules/security-group/aws"
+  source = "./mock-modules/security-group"
 
   name   = "postgres_sg"
   vpc_id = module.core_vpc.vpc_id

examples/platform/component_redis.tf

@@ -1,26 +1,15 @@
 # An in-memory data structure store used as a cache or message broker.
 # @title: Redis Cache
 module "tr_component_redis" {
-  source = "cloudposse/elasticache-redis/aws"
+  source = "./mock-modules/elasticache-redis"
 
   for_each = local.tr_component_redis
 
   availability_zones         = local.azs
-  vpc_id                     = module.core_vpc.default_vpc_id
+  vpc_id                     = module.core_vpc.vpc_id
   allowed_security_group_ids = [module.core_vpc.default_security_group_id]
   subnets                    = module.core_vpc.elasticache_subnets
   apply_immediately          = true
   automatic_failover_enabled = false
   engine_version             = each.value.version
-
-  context = module.this.context
-}
-
-module "this" {
-  source = "cloudposse/label/null"
-  # Cloud Posse recommends pinning every module to a specific version
-  # version = "x.x.x"
-  namespace = "var.namespace"
-  stage     = "var.stage"
-  name      = "var.name"
 }

examples/platform/component_server.tf

@@ -0,0 +1,39 @@
+# A server that hosts and serves static files.
+# @title: Static Server
+module "tr_component_server_static" {
+  source = "./mock-modules/bucket-static-site"
+
+  for_each = local.tr_component_server_static
+
+  bucket_name = each.key
+}
+
+module "k8s_cluster" {
+  source = "./mock-modules/k8s-cluster"
+}
+
+# A server that hosts web applications and handles HTTP requests.
+# @title: Web Server
+module "tr_component_server_web" {
+  source = "./mock-modules/k8s-service"
+
+  for_each = local.tr_component_server_web
+
+  cluster_id = module.k8s_cluster.cluster_id
+  is_public = true
+  name = each.key
+  port = each.value.port
+}
+
+# A server that is not exposed to the public internet.
+# @title: Private Server
+module "tr_component_server_private" {
+  source = "./mock-modules/k8s-service"
+
+  for_each = local.tr_component_server_private
+
+  cluster_id = module.k8s_cluster.cluster_id
+  is_public = false
+  name = each.key
+  port = each.value.port
+}

examples/platform/mock-modules/bucket-static-site/main.tf

@@ -0,0 +1,26 @@
+variable "bucket_name" {
+  description = "Name of the bucket"
+  type        = string
+  default = "by_bucket"
+}
+
+variable "index_document" {
+  description = "Index document for the website"
+  type        = string
+  default = "index.html"
+}
+
+variable "error_document" {
+  description = "Error document for the website"
+  type        = string
+  default = "error.html"
+}
+
+resource "random_pet" "random" {
+  length  = 2
+}
+
+output "website_endpoint" {
+  description = "The website endpoint URL"
+  value       = "http://${random_pet.random.id}.mocksite.com"
+}

examples/platform/mock-modules/cloud-scheduler/main.tf

@@ -0,0 +1,20 @@
+variable "name" {
+  type = string
+  description = "Name of the scheduler"
+  default = "default"
+}
+
+variable "event_receiver_url" {
+  type = string
+  description = "URL to push the events to"
+  default = ""
+}
+
+resource "random_id" "random" {
+  byte_length = 8
+}
+
+output "scheduler_id" {
+  description = "Id of the scheduler"
+  value = random_id.random.id
+}

examples/platform/mock-modules/elasticache-redis/main.tf

@@ -0,0 +1,72 @@
+# --- Input
+
+variable "availability_zones" {
+  type        = list(string)
+  description = "A list of availability zones in which to place the cluster"
+  default     = ["us-west-1a", "us-west-1b"]
+}
+
+variable "vpc_id" {
+  type        = string
+  description = "The VPC ID where the cluster is created"
+  default     = "vpc-12345678"
+}
+
+variable "allowed_security_group_ids" {
+  type        = list(string)
+  description = "A list of Security Group IDs that are allowed to access the cluster"
+  default     = ["sg-12345678"]
+}
+
+variable "subnets" {
+  type        = list(string)
+  description = "A list of subnet IDs for the cluster"
+  default     = ["subnet-12345678", "subnet-23456789"]
+}
+
+variable "apply_immediately" {
+  type        = bool
+  description = "Specifies whether any modifications are applied immediately, or during the next maintenance window"
+  default     = true
+}
+
+variable "automatic_failover_enabled" {
+  type        = bool
+  description = "Specifies whether a read-only replica will be automatically promoted to primary if the existing primary fails"
+  default     = false
+}
+
+variable "engine_version" {
+  type        = string
+  description = "The version number of the cache engine to use"
+  default     = "6.x"
+}
+
+# --- Config
+
+resource "random_pet" "redis_instance" {
+  length = 2
+}
+
+resource "random_password" "redis_password" {
+  length  = 16
+  special = true
+}
+
+# --- Output
+
+output "host" {
+  description = "The DNS name of the cache instance"
+  value       = "${random_pet.redis_instance.id}.mock-elasticache.com"
+}
+
+output "port" {
+  description = "The port number on which each of the cache nodes will accept connections"
+  value       = "6379" # Default Redis port
+}
+
+output "password" {
+  description = "The password used to access a password-protected Redis server"
+  value       = random_password.redis_password.result
+  sensitive = true
+}

examples/platform/mock-modules/k8s-cluster/main.tf

@@ -0,0 +1,14 @@
+variable "name" {
+  type = string
+  description = "Name cluster name"
+  default = ""
+}
+
+resource "random_id" "random" {
+  byte_length = 8
+}
+
+output "cluster_id" {
+  description = "cluster id"
+  value       = random_id.random.id
+}

examples/platform/mock-modules/k8s-service/main.tf

@@ -0,0 +1,32 @@
+variable "name" {
+  type = string
+  description = "Name of the service"
+  default = ""
+}
+
+variable "port" {
+  type = number
+  description = "Port to bind the service at"
+  default = 80
+}
+
+variable "cluster_id" {
+  type = string
+  description = "ID of the cluster"
+  default = ""
+}
+
+variable "is_public" {
+  type = bool
+  description = "Should this service be exposed to the public network"
+  default = false
+}
+
+resource "random_pet" "random" {
+  length  = 2
+}
+
+output "host" {
+  description = "The service host"
+  value       = "${random_pet.random.id}.mocksite.com"
+}

examples/platform/mock-modules/pubsub-queue/main.tf

@@ -0,0 +1,25 @@
+variable "name" {
+  type = string
+  description = "Name of the queue"
+  default = "default"
+}
+
+variable "event_receiver_url" {
+  type = string
+  description = "URL for push based model where the events are sent to the given url"
+  default = ""
+}
+
+resource "random_id" "random" {
+  byte_length = 8
+}
+
+output "queue_id" {
+  description = "Id of the queue"
+  value = random_id.random.id
+}
+
+output "queue_url" {
+  description = "URL of the queue to send events at and query for messages using sdk"
+  value = "http://${random_id.random.id}.mockqueue.com"
+}