how to custom plugins in the simulator

[Loong435]

Hello, I'm currently learning how to use Kubernetes scheduling, and I'm following your tutorial on creating a custom scheduler with a simulator. I've been trying for two days but still can't achieve the expected output for the "NodeNumber" plugin, as shown in your final screenshot. Could you help me figure out where I might have gone wrong? Below are all the screenshots from my setup process and the modifications I've made.Thank you so much!

[Loong435]

[sanposhiho]

cc @YamasouA

[sanposhiho]

Actually, we're in the transition phase to a new way of inserting a custom plugin.

You may want to try out a new simulator/docs/debuggable-scheduler.md ("Integrate your plugins to the simulator" section) in this PR: #382

[Loong435]

Hi，Thanks a lot for your response! I went through the issue you pointed out and have a couple of questions if you don’t mind.

I noticed that you’ve updated a lot of source code across different files, but it looks like those changes aren’t reflected in the main project files yet. Do you have an estimate on when those updates might be pushed?

Also, if I want to try the approach in simulator/docs/debuggable-scheduler.md, would it be best to wait until those updates are live, or should I go ahead and manually apply the changes you made across the project before testing?

Thanks again for any extra details you can share! I really appreciate the help.

[sanposhiho]

Our next release will come when #382 is merged, which should be very soon.
I believe a new simulator/docs/debuggable-scheduler.md should work with the current latest master branch, if not, that's a bug. Some implementation changes are made in #382 too though, they are all about the cleanup.

[Loong435]

Hi sanposhiho,

Sorry to bother you again, and thanks so much for your help so far!

I followed your new tutorial and tried to implement the custom scheduler. If I understood correctly, I replaced the contents of kubeconfig.yaml, scheduler.go, and scheduler.yaml with the example files you provided. From what I gathered, that should be enough to get the custom scheduler working.

However, I ran into some errors when running it. I've attached the modified files and the error screenshots below.

If you don’t mind, could you take a look and let me know what I might have missed? I’d really appreciate it!

Thanks again!

[Loong435]

I didn’t add any new files, but I don’t know why simply modifying some parts of the code causes an error saying that the kubeconfig.yaml file could not be found. Could it be that some configurations need to be adjusted, and the corresponding file needs to be mounted? Could you please help me resolve this issue?

[sanposhiho]

I rechecked on my side but the doc perfectly worked for me. I suspect that you did something that wan't on the doc, which caused the issue.

[sanposhiho]

I replaced the contents of kubeconfig.yaml, scheduler.go, and scheduler.yaml with the example files you provided. From what I gathered, that should be enough to get the custom scheduler working.

Why did you need to change kubeconfig and scheduler config?

[Loong435]

I replaced the contents of kubeconfig.yaml, scheduler.go, and scheduler.yaml with the example files you provided. From what I gathered, that should be enough to get the custom scheduler working.

Why did you need to change kubeconfig and scheduler config?

Thank you for your response. I modified the configuration file because I noticed that the file names in the /debuggable-scheduler/ directory were identical to those in the simulator/cmd/scheduler/ directory in your example. I thought I needed to replace everything inside.
Thank you for your response. I modified the configuration file because I noticed that the file names in the /debuggable-scheduler/ directory were identical to those in the simulator/cmd/scheduler/ directory in your example. I thought I needed to replace everything inside.
command, cancelFn, err := debuggablescheduler.NewSchedulerCommand()
with:
command, cancelFn, err := debuggablescheduler.NewSchedulerCommand(
debuggablescheduler.WithPlugin(nodenumber.Name, nodenumber.New), // Register the custom scheduler plugin.
debuggablescheduler.WithPluginExtenders(noderesources.Name, extender.New) // [Optional] Register the extender plugin
)
The program runs without errors, but I can’t see any changes in the web UI. Could you please help me understand why this might be happening? I really appreciate your help with this simple question, and I’d be extremely grateful if you could assist me further.
The configuration environment information for the Web UI after running Docker is as follows:
kind: KubeSchedulerConfiguration
apiVersion: kubescheduler.config.k8s.io/v1
parallelism: 16
leaderElection:
leaderElect: true
leaseDuration: 15s
renewDeadline: 10s
retryPeriod: 2s
resourceLock: leases
resourceName: kube-scheduler
resourceNamespace: kube-system
clientConnection:
kubeconfig: ''
acceptContentTypes: ''
contentType: application/vnd.kubernetes.protobuf
qps: 50
burst: 100
enableProfiling: true
enableContentionProfiling: true
percentageOfNodesToScore: 0
podInitialBackoffSeconds: 1
podMaxBackoffSeconds: 10
profiles:

• schedulerName: default-scheduler
  plugins:
  preEnqueue: {}
  queueSort: {}
  preFilter: {}
  filter: {}
  postFilter: {}
  preScore: {}
  score: {}
  reserve: {}
  permit: {}
  preBind: {}
  bind: {}
  postBind: {}
  multiPoint:
  enabled:
  - name: SchedulingGates
  - name: PrioritySort
  - name: NodeUnschedulable
  - name: NodeName
  - name: TaintToleration
  weight: 3
  - name: NodeAffinity
  weight: 2
  - name: NodePorts
  - name: NodeResourcesFit
  weight: 1
  - name: VolumeRestrictions
  - name: EBSLimits
  - name: GCEPDLimits
  - name: NodeVolumeLimits
  - name: AzureDiskLimits
  - name: VolumeBinding
  - name: VolumeZone
  - name: PodTopologySpread
  weight: 2
  - name: InterPodAffinity
  weight: 2
  - name: DefaultPreemption
  - name: NodeResourcesBalancedAllocation
  weight: 1
  - name: ImageLocality
  weight: 1
  - name: DefaultBinder
  pluginConfig:
  • name: DefaultPreemption
    args:
    kind: DefaultPreemptionArgs
    apiVersion: kubescheduler.config.k8s.io/v1
    minCandidateNodesPercentage: 10
    minCandidateNodesAbsolute: 100
  • name: InterPodAffinity
    args:
    kind: InterPodAffinityArgs
    apiVersion: kubescheduler.config.k8s.io/v1
    hardPodAffinityWeight: 1
    ignorePreferredTermsOfExistingPods: false
  • name: NodeAffinity
    args:
    kind: NodeAffinityArgs
    apiVersion: kubescheduler.config.k8s.io/v1
  • name: NodeResourcesBalancedAllocation
    args:
    kind: NodeResourcesBalancedAllocationArgs
    apiVersion: kubescheduler.config.k8s.io/v1
    resources:
    - name: cpu
    weight: 1
    - name: memory
    weight: 1
  • name: NodeResourcesFit
    args:
    kind: NodeResourcesFitArgs
    apiVersion: kubescheduler.config.k8s.io/v1
    scoringStrategy:
    type: LeastAllocated
    resources:
    - name: cpu
    weight: 1
    - name: memory
    weight: 1
  • name: PodTopologySpread
    args:
    kind: PodTopologySpreadArgs
    apiVersion: kubescheduler.config.k8s.io/v1
    defaultingType: System
  • name: VolumeBinding
    args:
    kind: VolumeBindingArgs
    apiVersion: kubescheduler.config.k8s.io/v1
    bindTimeoutSeconds: 600

[sanposhiho]

The program runs without errors, but I can’t see any changes in the web UI.

It's unclear what is the problem.
Please explain the problem you're facing and provide the simple process to reproduce it.