Panic when creating InstanceGroup with custom-networking annotations

[preflightsiren]

Is this a BUG REPORT or FEATURE REQUEST?: Bug report

What happened: instance-manager panics with nil point dereference

What you expected to happen: IM not to crash :P

How to reproduce it (as minimally and precisely as possible):
Create a new instanceGroup with annotations:

metadata:
  annotations:
    instancemgr.keikoproj.io/custom-networking-enabled: "true"
    instancemgr.keikoproj.io/custom-networking-host-pods: "6"

Anything else we need to know?: It only occurs when creating a new instanceGroup. Annotating a new instanceGroup is unaffected.

Environment: AWS EKS.

• Kubernetes version: 1.17

kubectl version -o yaml

Other debugging information (if applicable):

I've run instance-manager locally with patch:

diff --git a/controllers/provisioners/eks/helpers.go b/controllers/provisioners/eks/helpers.go
index f764441..68398e2 100644
--- a/controllers/provisioners/eks/helpers.go
+++ b/controllers/provisioners/eks/helpers.go
@@ -471,6 +471,10 @@ func (ctx *EksInstanceGroupContext) GetComputedBootstrapOptions() *v1alpha1.Boot
                }

                instanceTypeNetworkInfo := awsprovider.GetInstanceTypeNetworkInfo(state.GetInstanceTypeInfo(), configuration.InstanceType)
+               if instanceTypeNetworkInfo == nil {
+                       ctx.Log.Error(nil, "state.GetInstanceTypeInfo()", "state.GetInstanceTypeInfo()", state.GetInstanceTypeInfo())
+                       ctx.Log.Error(nil, "configuration.InstanceType", "configuration.InstanceType", configuration.InstanceType)
+               }
                maxPods := (*instanceTypeNetworkInfo.MaximumNetworkInterfaces-1)*
                        (*instanceTypeNetworkInfo.Ipv4AddressesPerInterface-1) + hostNetworkPods
                if configuration.BootstrapOptions == nil {

which gives output:

2021-06-04T15:53:48.688+1000    ERROR   controllers.instancegroup.eks   state.GetInstanceTypeInfo()     {"state.GetInstanceTypeInfo()": []}
2021-06-04T15:53:48.688+1000    ERROR   controllers.instancegroup.eks   configuration.InstanceType      {"configuration.InstanceType": "m5.xlarge"}

and confirms that instanceTypeNetworkInfo is nil (likely because state.GetInstanceTypeInfo() returns [])