Fleet/GameServerSet Validation: Able to create a Fleet with label and annotations length > 63 symbols

[aLekSer]

There is an option to create an invalid fleet or gameserverset with oversized label length.

What happened:

Fleet was created successfully.

What you expected to happen:

There should be an error on a Fleet validation.

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

Fleet configuration fleet.yaml:

apiVersion: "agones.dev/v1"
kind: Fleet
metadata:
  name: check-the-fleet
spec:
  replicas: 3
  scheduling: Packed
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  template:
    metadata:
      labels:
        e123456: a123456789012345678901234567890123456789012345678901234567890123
    spec:
      ports:
      - name: default
        containerPort: 7654
      template:
        spec:
          containers:
          - name: simple-udp
            image: gcr.io/agones-images/udp-server:0.17

Run:

$ kubectl apply -f ./fleet.yaml
$ kubectl get fleets
NAME              SCHEDULING   DESIRED   CURRENT   ALLOCATED   READY   AGE
check-the-fleet   Packed       3                                       8m

Same steps aplies to GSS if you change Fleet to kind: GameServerSet with no errors on create.

Error in Controller logs:

error creating gameserverset for fleet check-the-fleet: GameServerSet.agones.dev "check-the-fleet-w4vdd" is invalid: metadata.labels: Invalid value: "a123456789012345678901234567890123456789012345678901234567890123": must be no more than 63 characters

Anything else we need to know?:

Environment:

• Agones version: 1.2.0
• Kubernetes version (use kubectl version):
  Client Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.3", GitCommit:"b3cbbae08ec52a7fc73d334838e18d17e8512749", GitTreeState:"clean", BuildDate:"2019-11-13T11:23:11Z", GoVersion:"go1.12.12", Compiler:"gc", Platform:"darwin/amd64"}
  Server Version: version.Info{Major:"1", Minor:"13+", GitVersion:"v1.13.12-gke.13", GitCommit:"39fe6cf6b77a3a0f620bd89db92f5133be67aa91", GitTreeState:"clean", BuildDate:"2019-11-13T20:44:51Z", GoVersion:"go1.12.11b4", Compiler:"gc", Platform:"linux/amd64"}
• Cloud provider or hardware configuration:
• Install method (yaml/helm):
• Troubleshooting guide log(s):
• Others:

[aLekSer]

Similar validation for Pods:
https://github.com/kubernetes/kubernetes/pull/1830/files

[aLekSer]

Working on a solution to this issue.
Also note that there is one more place where we could have long labels in Spec.Template.Spec.Template:

apiVersion: "agones.dev/v1"
kind: Fleet
metadata:
  name: check-the-fleet
spec:
  replicas: 3
  scheduling: Packed
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  template:   
   spec:
    ports:
    - name: default
      containerPort: 7654
    template:
      metadata:
        labels:
          e123456: a123456789012345678901234567890123456789012345678901234567890123
      spec:
        containers:
        - name: simple-udp
          image: gcr.io/agones-images/udp-server:0.17

This will result in no GameServer could be created :

Pod " check-the-fleet-kbp6h-9krdv" is invalid: metadata.labels: Invalid value: "a123456789012345678901234567890123456789012345678901234567890123": must be no more than 63 characters

https://gist.github.com/aLekSer/b490a8e129986d102685abc2269c65e6

[aLekSer]

Same applies to annotations key length, which should not exceed 63 symbols as well:
https://kubernetes.io/docs/concepts/overview/working-with-objects/annotations/
Example which cause infinite GameServers creation:

apiVersion: "agones.dev/v1"
kind: Fleet
metadata:
  name: check-the-fleet2
spec:
  replicas: 3
  scheduling: Packed
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
  template:
    spec:
      ports:
        - name: default
          containerPort: 7654
      template:
        metadata:
          annotations:
            a123456789012345678901234567890123456789012345678901234567890123: a123456789012345678901234567890123456789012345678901234567890123
        spec:
          containers:
            - name: simple-udp
              image: gcr.io/agones-images/udp-server:0.17

[aLekSer]

This might be useful for Annotations validation:
https://github.com/kubernetes/kubernetes/blob/7f23a743e8c23ac6489340bbb34fa6f1d392db9d/staging/src/k8s.io/apimachinery/pkg/api/validation/objectmeta.go

[aLekSer]

Working on the annotation fix in a branch:
https://github.com/aLekSer/agones/tree/validateAnnotations
Will send a PR after the Labels fix, because of dependencies between them.