From 17c1e3467b4e422cf37a7e582af0a8462b065456 Mon Sep 17 00:00:00 2001
From: shockrah <alejandros714@protonmail.com>
Date: Sun, 28 Nov 2021 15:24:26 -0800
Subject: [PATCH] * Fixing NAT gateway for proper usage from crete members With
 this patch members of Crete can now get system patches

---
 infra/eip.tf         |  1 +
 infra/gateway.tf     | 13 +++++++++----
 infra/route-table.tf | 27 ++++++++++++++++++++++-----
 3 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/infra/eip.tf b/infra/eip.tf
index 636c9eb..9be52bc 100644
--- a/infra/eip.tf
+++ b/infra/eip.tf
@@ -15,6 +15,7 @@ resource "aws_eip" "gamma_eip" {
   }
 }
 
+# This EIP is reserved for the NAT gateway which lives in Olympus
 resource "aws_eip" "demeter_eip" {
   vpc = true
   tags = {
diff --git a/infra/gateway.tf b/infra/gateway.tf
index c80338c..1776077 100644
--- a/infra/gateway.tf
+++ b/infra/gateway.tf
@@ -1,16 +1,21 @@
+# Used to provide internet access for instances in the VPC
 resource "aws_internet_gateway" "athens_internet_gateway" {
   vpc_id = aws_vpc.athens_vpc.id
 
   tags = {
-    Name = "Athens Common Internet Gateway"
+    Name = "Athens Common Internet Gateway in Olypmus"
   }
 }
 
-resource "aws_nat_gateway" "athens_nat_gateway" {
+# NAT lives in the public subnet because it has an EIP
+# which is the main requirement to be situated in Olympus
+resource "aws_nat_gateway" "crete_nat_gateway" {
   allocation_id = aws_eip.demeter_eip.id
-  subnet_id = aws_subnet.crete_subnet.id
+  subnet_id = aws_subnet.olympus_subnet.id
 
   tags = {
-    Name = "Demeter - Crete' NAT"
+    Name = "Demeter - Crete's NAT located in Olympus"
   }
+  # Ensure this resource is created after the internet gateway
+  depends_on = [aws_internet_gateway.athens_internet_gateway]
 }
diff --git a/infra/route-table.tf b/infra/route-table.tf
index de2a07d..99a8f7c 100644
--- a/infra/route-table.tf
+++ b/infra/route-table.tf
@@ -1,17 +1,34 @@
-resource "aws_route_table" "crete_route_table" {
+# NOTE: local traffic route is implied and does not need to be specified
+resource "aws_route_table" "olympus_route_table" {
   vpc_id = aws_vpc.athens_vpc.id
   route {
-    # ????
     cidr_block = "0.0.0.0/0"
     gateway_id = aws_internet_gateway.athens_internet_gateway.id
   }
+
   tags = {
-    Name = "Crete Route Table"
+    Name = "Olympush IGW Route Table"
   }
 }
+resource "aws_route_table_association" "olympus_gateway_association" {
+  subnet_id = aws_subnet.olympus_subnet.id
+  route_table_id = aws_route_table.olympus_route_table.id
+}
 
-resource "aws_route_table_association" "crete_gateway_association" {
+
+# Here we route crete's traffic to the nat
+# NOTE: The NAT is actually located in Olympus because it has an EIP
+resource "aws_route_table" "crete_route_table" {
+  vpc_id = aws_vpc.athens_vpc.id
+  route {
+    cidr_block = "0.0.0.0/0"
+    nat_gateway_id = aws_nat_gateway.crete_nat_gateway.id
+  }
+  tags = {
+    Name = "Crete NAT Route Table"
+  }
+}
+resource "aws_route_table_association" "crete_nat_association" {
   subnet_id = aws_subnet.crete_subnet.id
   route_table_id = aws_route_table.crete_route_table.id
 }
-