From 5ede2c298bca53d8f5d45ffae5a0396c1d427385 Mon Sep 17 00:00:00 2001
From: andrewpatto <andrew@patto.net>
Date: Tue, 12 Sep 2023 10:59:28 +1000
Subject: [PATCH] More isolated subnet missing behaviour

---
 packages/client/infrastructure-client.ts | 28 ++++++++++++++++++++----
 packages/stack/infrastructure-stack.ts   |  8 +++----
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/packages/client/infrastructure-client.ts b/packages/client/infrastructure-client.ts
index 22bfadd..0f995ba 100644
--- a/packages/client/infrastructure-client.ts
+++ b/packages/client/infrastructure-client.ts
@@ -100,12 +100,30 @@ export class InfrastructureClient {
 
     // try to bring in this private subnets if present
     try {
-      vpcAttrs.privateSubnetIds = getStringListLookup(
+      vpcAttrs.privateSubnetIds = undefined;
+      vpcAttrs.privateSubnetRouteTableIds = undefined;
+
+      const privateSubs = getStringListLookup(
         vpcPrivateSubnetIdsParameterName(this.infrastructureStackId),
       );
-      vpcAttrs.privateSubnetRouteTableIds = getStringListLookup(
-        vpcPrivateSubnetRouteTableIdsParameterName(this.infrastructureStackId),
-      );
+
+      // sometimes even if the private subnets parameter does not exist - what comes back is a string
+      // error message - hence our test here to really really establish we have real subnets
+      // this handles various "empty" private subs cases
+      if (
+        privateSubs &&
+        privateSubs.length > 0 &&
+        privateSubs[0].includes("subnet-")
+      ) {
+        vpcAttrs.privateSubnetIds = privateSubs;
+
+        // the assumption is that if private subnets was set - so was its routing
+        vpcAttrs.privateSubnetRouteTableIds = getStringListLookup(
+          vpcPrivateSubnetRouteTableIdsParameterName(
+            this.infrastructureStackId,
+          ),
+        );
+      }
     } catch (e) {}
 
     // try to bring in the isolated subnets if present
@@ -119,6 +137,7 @@ export class InfrastructureClient {
 
       // sometimes even if the isolated subnets parameter does not exist - what comes back is a string
       // error message - hence our test here to really really establish we have real subnets
+      // this handles various "empty" private subs cases
       if (
         isolatedSubs &&
         isolatedSubs.length > 0 &&
@@ -126,6 +145,7 @@ export class InfrastructureClient {
       ) {
         vpcAttrs.isolatedSubnetIds = isolatedSubs;
 
+        // the assumption is that if isolated subnets was set - so was its routing
         vpcAttrs.isolatedSubnetRouteTableIds = getStringListLookup(
           vpcIsolatedSubnetRouteTableIdsParameterName(
             this.infrastructureStackId,
diff --git a/packages/stack/infrastructure-stack.ts b/packages/stack/infrastructure-stack.ts
index 391933b..35e1d69 100644
--- a/packages/stack/infrastructure-stack.ts
+++ b/packages/stack/infrastructure-stack.ts
@@ -112,12 +112,12 @@ export class InfrastructureStack extends Stack {
       });
     } else {
       // CDK has strange behaviour when looking up "optional" parameters - so instead
-      // we create a parameter of zero length to indicate that we do not have any
+      // we create a parameter with a single empty string to indicate that we do not have any
       // private subnets
       // our infrastructure client handles the other end of this behaviour
       new StringListParameter(this, "PrivateSubnetIdsParameter", {
         parameterName: vpcPrivateSubnetIdsParameterName(id),
-        stringListValue: [],
+        stringListValue: [""],
       });
     }
 
@@ -135,12 +135,12 @@ export class InfrastructureStack extends Stack {
       });
     } else {
       // CDK has strange behaviour when looking up "optional" parameters - so instead
-      // we create a parameter of zero length to indicate that we do not have any
+      // we create a parameter with a single empty string to indicate that we do not have any
       // isolated subnets
       // our infrastructure client handles the other end of this behaviour
       new StringListParameter(this, "IsolatedSubnetIdsParameter", {
         parameterName: vpcIsolatedSubnetIdsParameterName(id),
-        stringListValue: [],
+        stringListValue: [""],
       });
     }