If GameServer webhook validation fails, it doesn't raise up to Fleet

[markmandel]

What happened:
Create a Fleet with an invalid GameServer specification - no error was returned, and no GameServer was created.

For example (container is in the wrong spot):

apiVersion: "stable.agones.dev/v1alpha1"
kind: Fleet
metadata:
  name: zoba-fleet
spec:
  container: 1st
  replicas: 1
  scheduling: Packed
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  template:
    metadata:
      labels:
        foo: bar
    spec:
      ports:
      - name: default
        portPolicy: Dynamic
        containerPort: 7788
      - containerPort: 3434
        protocol: TCP
        name: tcp
      health:
        initialDelaySeconds: 30
        periodSeconds: 10
      template:
        spec:
          containers:
          - name: 1st
            image: nginx
          - name: 2nd
            image: debian
            volumeMounts:
            - name: html
              mountPath: /html
            command: ["/bin/sh", "-c"]
            args:
              - while true; do
                  date >> /html/index.html;
                  sleep 1;
                done

What you expected to happen:

Should return a validation error as soon as the Fleet is created - i.e. the Fleet shouldn't get created at all, and the user should get a message as to why.

How to reproduce it (as minimally and precisely as possible):

copy paste the above into bad-fleet.yaml, and kubectl apply -f bad-fleet.yaml

Anything else we need to know?:

Environment:

• Agones version: 0.9.0
• Kubernetes version (use kubectl version): 1.11.x
• Cloud provider or hardware configuration: ???
• Install method (yaml/helm): ???
• Troubleshooting guide log(s): ???
• Others:

[aLekSer]

I will make a pull request to fix this issue.