The ec2 vpcendpointserviceconfiguration resource crashes with nil pointer error

[EdgeJ]

While testing another resource, I applied the entirety of the ec2 examples. Afterward, the aws-provider began crashing with nil pointer errors with the following error log:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x3dd116e]

goroutine 5130 [running]:
github.com/crossplane-contrib/provider-aws/pkg/controller/ec2/vpcendpointserviceconfiguration.GenerateObservation(...)
	/Users/jedge/git/crossplane/provider-aws/pkg/controller/ec2/vpcendpointserviceconfiguration/setup.go:287
github.com/crossplane-contrib/provider-aws/pkg/controller/ec2/vpcendpointserviceconfiguration.postObserve({0x0, 0x0}, 0xc00064e480, 0xc00261bbc0, {0x1, 0x1, 0x1, 0x0, {0x0, 0x0}}, ...)
	/Users/jedge/git/crossplane/provider-aws/pkg/controller/ec2/vpcendpointserviceconfiguration/setup.go:84 +0x14e
github.com/crossplane-contrib/provider-aws/pkg/controller/ec2/vpcendpointserviceconfiguration.(*external).Observe(0xc0018640e0, {0x7144250, 0xc002b312c0}, {0x721f2b0, 0xc00064e480})
	/Users/jedge/git/crossplane/provider-aws/pkg/controller/ec2/vpcendpointserviceconfiguration/zz_controller.go:99 +0x3ff
github.com/crossplane/crossplane-runtime/pkg/reconciler/managed.(*Reconciler).Reconcile(0xc00052abb0, {0x7144288, 0xc0011f1290}, {{{0x0, 0x64ba400}, {0xc0004fa920, 0x30}}})
	/Users/jedge/go1.17/pkg/mod/github.com/crossplane/crossplane-runtime@v0.15.1-0.20220315141414-988c9ba9c255/pkg/reconciler/managed/reconciler.go:767 +0x230b
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Reconcile(0xc00052ac60, {0x7144288, 0xc0011f11d0}, {{{0x0, 0x64ba400}, {0xc0004fa920, 0x1015034}}})
	/Users/jedge/go1.17/pkg/mod/sigs.k8s.io/controller-runtime@v0.11.0/pkg/internal/controller/controller.go:114 +0x26f
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).reconcileHandler(0xc00052ac60, {0x71441e0, 0xc0005b73c0}, {0x5ff2d20, 0xc000660120})
	/Users/jedge/go1.17/pkg/mod/sigs.k8s.io/controller-runtime@v0.11.0/pkg/internal/controller/controller.go:311 +0x33e
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem(0xc00052ac60, {0x71441e0, 0xc0005b73c0})
	/Users/jedge/go1.17/pkg/mod/sigs.k8s.io/controller-runtime@v0.11.0/pkg/internal/controller/controller.go:266 +0x205
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func2.2()
	/Users/jedge/go1.17/pkg/mod/sigs.k8s.io/controller-runtime@v0.11.0/pkg/internal/controller/controller.go:227 +0x85
created by sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func2
	/Users/jedge/go1.17/pkg/mod/sigs.k8s.io/controller-runtime@v0.11.0/pkg/internal/controller/controller.go:223 +0x357
exit status 2

Digging in a little, I discovered the error was coming from these lines:

provider-aws/pkg/controller/ec2/vpcendpointserviceconfiguration/setup.go

Lines 286 to 291 in 34be513

	PrivateDNSNameConfiguration: &svcapitypes.PrivateDNSNameConfiguration{
	Name: obj.PrivateDnsNameConfiguration.Name,
	State: obj.PrivateDnsNameConfiguration.State,
	Value: obj.PrivateDnsNameConfiguration.Value,
	Type: obj.PrivateDnsNameConfiguration.Type,
	},

Describing the generated endpoint service configuration with the aws cli does not have the PrivateDnsNameConfiguration section supplied:

ServiceConfigurations:
- AcceptanceRequired: true
  AvailabilityZones:
  - us-east-1b
  - us-east-1c
  GatewayLoadBalancerArns:
  - arn:aws:elasticloadbalancing:us-east-1:<REDACTED>:loadbalancer/gwy/gatewayloadbalancer/c133378d9015d865
  ManagesVpcEndpoints: false
  ServiceId: vpce-svc-0e8b9215e9b8ef7b8
  ServiceName: com.amazonaws.vpce.us-east-1.vpce-svc-0e8b9215e9b8ef7b8
  ServiceState: Available
  ServiceType:
  - ServiceType: GatewayLoadBalancer
  Tags:
  - Key: crossplane-providerconfig
    Value: example
  - Key: crossplane-kind
    Value: vpcendpointserviceconfiguration.ec2.aws.crossplane.io
  - Key: crossplane-name
    Value: sample-vpc-endpoint-service
  - Key: Name
    Value: sample-vpc-endpoint-service

so, I'm pretty sure that there needs to be a check around this configuration to make sure the result from the Describe action is not nil, before setting values from it.