Output JSON unmarshal error as Admission response

[aLekSer]

Add Error into response of AdmissionReview with UT.

Closes #992 .

[agones-bot]

Build Succeeded 👏

Build Id: fa547dba-9f62-4e1d-82fb-d4f3c9ddd731

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:1.0.0-e6d78e7
• image: gcr.io/agones-images/agones-sdk:1.0.0-e6d78e7
• image: gcr.io/agones-images/agones-ping:1.0.0-e6d78e7
• Linux C++ SDK (build): agonessdk-1.0.0-e6d78e7-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.0.0-e6d78e7.zip

A preview of the website (the last 30 builds are retained):

• https://e6d78e7-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/GoogleCloudPlatform/agones.git pull/1005/head:pr_1005 && git checkout pr_1005
• helm install install/helm/agones --namespace agones-system --name agones --set agones.image.tag=1.0.0-e6d78e7

[aLekSer]

/lint

[google-oss-robot]

@aLekSer: 0 warnings.

In response to this:

/lint

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[aLekSer]

/assign @aLekSer

[agones-bot]

Build Succeeded 👏

Build Id: 7efe3f00-92b2-4a48-8de6-82ba67f2544d

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:1.0.0-c4bc8b9
• image: gcr.io/agones-images/agones-sdk:1.0.0-c4bc8b9
• image: gcr.io/agones-images/agones-ping:1.0.0-c4bc8b9
• Linux C++ SDK (build): agonessdk-1.0.0-c4bc8b9-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.0.0-c4bc8b9.zip

A preview of the website (the last 30 builds are retained):

• https://c4bc8b9-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/GoogleCloudPlatform/agones.git pull/1005/head:pr_1005 && git checkout pr_1005
• helm install install/helm/agones --namespace agones-system --name agones --set agones.image.tag=1.0.0-c4bc8b9

[aLekSer]

Now we receive output from kubectl CLI, in such form:

kubectl apply -f ../examples/simple-udp/fleet.yaml
Error from server (InternalError): error when creating "../examples/simple-udp/fleet.yaml": Internal error occurred: admission webhook "mutations.agones.dev" denied the request: error unmarshalling original Fleet json: {"apiVersion":"agones.dev/v1","kind":"Fleet","metadata":{"annotations":{"kubectl.kubernetes.io/last-applied-configuration":"{\"apiVersion\":\"agones.dev/v1\",\"kind\":\"Fleet\",\"metadata\":{\"annotations\":{},\"name\":\"simple-udp\",\"namespace\":\"default\"},\"spec\":{\"replicas\":2,\"template\":{\"spec\":{\"ports\":[{\"containerPort\":7654,\"name\":false}],\"template\":{\"spec\":{\"containers\":[{\"image\":\"gcr.io/agones-images/udp-server:0.14\",\"name\":\"simple-udp\",\"resources\":{\"limits\":{\"cpu\":\"20m\",\"memory\":\"64Mi\"},\"requests\":{\"cpu\":\"20m\",\"memory\":\"64Mi\"}}}]}}}}}}\n"},"creationTimestamp":null,"name":"simple-udp","namespace":"default"},"spec":{"replicas":2,"template":{"spec":{"ports":[{"containerPort":7654,"name":false}],"template":{"spec":{"containers":[{"image":"gcr.io/agones-images/udp-server:0.14","name":"simple-udp","resources":{"limits":{"cpu":"20m","memory":"64Mi"},"requests":
{"cpu":"20m","memory":"64Mi"}}}]}}}}}}: json: cannot unmarshal bool into Go struct field GameServerPort.name of type string  

Here I set spec.template.spec.ports.name = false for simple-udp/fleet.yaml

[markmandel]

Love this. This is going to be great for our users!

[google-oss-robot]

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