Frontend Router terraform module

This modules crates components needed to be able to expose your application(s) to the public.

When included and configured this module will:

• create public ALB
• create a HTTPS Listener on default ALB with default rule
• the default rule will be either 404 service (microservice which returns 404 responses to all requests) or haproxy proxy which will proxy all requests to configured BACKEND_IP
• output ALB Listener ARN and DNS Record for the ALB - you'll need both to be able to integrate your services with the ALB
• create Fastly configuration and 1:1 map it to the ALB (Fastly will log all requests to Logentries by default)

Finaly product is AWS ALB which you can configure your services to be attached.

NOTE - in order to use underlying Fastly dependency (within tf_fastly_frontend), you must set LOGENTRIES_ACCOUNT_KEY environment variable before you use this module - otherwise tf_fastly_frontend module won't be able to create Logentries Logset and will fail.

Module Input Variables

• fastly_domain - (string) - REQUIRED - DNS Domain name to be used as a entry to the service (Fastly will be configured to use it)
• team - (string) - REQUIRED - Name of Team deploying the ALB - will affect ALBs name
• env - (string) - REQUIRED - Environment deployed to
• component - (string) - REQUIRED - component name
• platform_config - (map) REQUIRED - Mergermarket Platform config dictionary (see tests for example one)
• alb_domain - (string) - REQUIRED DNS Domain name to be used as a entry to the service (Fastly will be configured to use it)
• bare_redirect_domain_name - (string) - If set, a service will be created in live to redirect this bare domain to the prefixed version - for example you might set this value to my-site.com in order to redirect users to www.my-site.com (default "", i.e. will not be used)
• backend_ip - (string) - If set to IP - it'll cause a proxying service to be deployed that will proxy - by default - all requests to given IP; this IP should be / can be different per environment and configured via config mechanism. Default 404 - will deploy service that - by default - returns 404s to all requests
• backend_port - (string) - Port number the requests to the backend will be sent to (default 80)
• fastly_caching - (bool) - Controls whether to enable / forcefully disable caching (default: true)
• ssl_cert_check - (bool) - Check the backend cert is valid - warning disabling this makes you vulnerable to a man-in-the-middle imporsonating your backend (default true)
• ssl_cert_hostname - (bool) - The hostname to validate the certificate presented by the backend against (default "")
• health_check_interval - (string) - (default "5") The approximate amount of time, in seconds, between health checks of an individual target. Minimum value 5 seconds, Maximum value 300 seconds.
• health_check_path - (string) - The destination for the health check request (default "/internal/healthcheck")
• health_check_timeout - (string) - The amount of time, in seconds, during which no response means a failed health check (default "4")
• health_check_healthy_threshold - (string) - The number of consecutive health checks successes required before considering an unhealthy target healthy (default "2")
• health_check_unhealthy_threshold - (string) - The number of consecutive health check failures required before considering the target unhealthy (default "2")
• health_check_matcher - (string) - The HTTP codes to use when checking for a successful response from a target. You can specify multiple values (for example, "200,202") or a range of values (for example, "200-299") (default "200-299")

Usage

# the below platform_config map can be passed as a TF var-file (eg. JSON file)
variable "platform_config" {
  type = "map"
  default  = {
    platform_config: {
      azs: "eu-west-1a,eu-west-1b,eu-west-1c",
      elb_certificates.domain_com: "arn:aws:acm:us-east-1:123456789012:certificate/12345678-1234-1234-1234-123456789012",
      route53_zone_id.domain_com: "AAAAAAAAAAAAA",
      ecs_cluster.default.client_security_group: "sg-00000000",
      ecs_cluster.default.security_group: "sg-11111111",
      vpc: "vpc-12345678",
      public_subnets: "subnet-00000000,subnet-11111111,subnet-22222222",
      logentries_fastly_logset_id: "111-222-333-444-555"
    }
  }
}

module "frontend_router" {
  source = "github.com/mergermarket/tf_frontend_router"

  fastly_domain   = "www.externaldomain.com"
  le_logset_id    = "${lookup(var.platform_config, "logentries_fastly_logset_id")}"
  alb_domain      = "domain.com"
  team            = "humptydumptyteam"
  env             = "ci"
  component       = "wall"
  platform_config = "${var.platform_config}"

  # optional
  # backend_ip              = "1.1.1.1"
  # fastly_caching          = "false"
  bare_redirect_domain_name = "externaldomain.com"
}

Outputs

• alb_dns_name - The DNS name of the load balancer
• alb_listener_arn - The ARN of the load balancer