Version: v1.2

FAQ

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What is the difference between KubeVela and Helm?

KubeVela is a platform builder tool to create easy-to-use yet extensible app delivery/management systems with Kubernetes. KubeVela relies on Helm as templating engine and package format for apps. But Helm is not the only templating module that KubeVela supports. Another first-class supported approach is CUE.

Also, KubeVela is by design a Kubernetes controller (i.e. works on server side), even for its Helm part, a Helm operator will be installed.

Issues

Error: unable to create new content in namespace cert-manager because it is being terminated

Occasionally you might hit the issue as below. It happens when the last KubeVela release deletion hasn’t completed.

  1. vela install
  1. - Installing Vela Core Chart:
  3. install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  5. Failed to install the chart with error: serviceaccounts "cert-manager-cainjector" is forbidden: unable to create new content in namespace cert-manager because it is being terminated
  7. failed to create resource
  9. helm.sh/helm/v3/pkg/kube.(*Client).Update.func1
  11.     /home/runner/go/pkg/mod/helm.sh/helm/v3@v3.2.4/pkg/kube/client.go:190
  13. ...
  15. Error: failed to create resource: serviceaccounts "cert-manager-cainjector" is forbidden: unable to create new content in namespace cert-manager because it is being terminated

Take a break and try again in a few seconds.

  1. vela install
  1. - Installing Vela Core Chart:
  3. Vela system along with OAM runtime already exist.
  5. Automatically discover capabilities successfully ✅ Add(0) Update(0) Delete(8)
  10. TYPE        CATEGORY    DESCRIPTION
  12. -task       workload    One-off task to run a piece of code or script to completion
  14. -webservice workload    Long-running scalable service with stable endpoint to receive external traffic
  16. -worker     workload    Long-running scalable backend worker without network endpoint
  18. -autoscale  trait       Automatically scale the app following certain triggers or metrics
  20. -metrics    trait       Configure metrics targets to be monitored for the app
  22. -rollout    trait       Configure canary deployment strategy to release the app
  24. -route      trait       Configure route policy to the app
  26. -scaler     trait       Manually scale the app
  31. - Finished successfully.

And manually apply all WorkloadDefinition and TraitDefinition manifests to have all capabilities back.

  1. vela up -f charts/vela-core/templates/defwithtemplate
  1. traitdefinition.core.oam.dev/autoscale created
  3. traitdefinition.core.oam.dev/scaler created
  5. traitdefinition.core.oam.dev/metrics created
  7. traitdefinition.core.oam.dev/rollout created
  9. traitdefinition.core.oam.dev/route created
  11. workloaddefinition.core.oam.dev/task created
  13. workloaddefinition.core.oam.dev/webservice created
  15. workloaddefinition.core.oam.dev/worker created
  1. vela workloads
  1. Automatically discover capabilities successfully ✅ Add(8) Update(0) Delete(0)
  6. TYPE        CATEGORY    DESCRIPTION
  8. +task       workload    One-off task to run a piece of code or script to completion
  10. +webservice workload    Long-running scalable service with stable endpoint to receive external traffic
  12. +worker     workload    Long-running scalable backend worker without network endpoint
  14. +autoscale  trait       Automatically scale the app following certain triggers or metrics
  16. +metrics    trait       Configure metrics targets to be monitored for the app
  18. +rollout    trait       Configure canary deployment strategy to release the app
  20. +route      trait       Configure route policy to the app
  22. +scaler     trait       Manually scale the app
  27. NAME        DESCRIPTION
  29. task        One-off task to run a piece of code or script to completion
  31. webservice  Long-running scalable service with stable endpoint to receive external traffic
  33. worker      Long-running scalable backend worker without network endpoint

Error: ScopeDefinition exists

Occasionally you might hit the issue as below. It happens when there is an old OAM Kubernetes Runtime release, or you applied ScopeDefinition before.

  1. vela install
  1.   - Installing Vela Core Chart:
  3.   install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  5.   Failed to install the chart with error: ScopeDefinition "healthscopes.core.oam.dev" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; annotation validation error: key "meta.helm.sh/release-name" must equal "kubevela": current value is "oam"; annotation validation error: key "meta.helm.sh/release-namespace" must equal "vela-system": current value is "oam-system"
  7.   rendered manifests contain a resource that already exists. Unable to continue with install
  9.   helm.sh/helm/v3/pkg/action.(*Install).Run
  11.     /home/runner/go/pkg/mod/helm.sh/helm/v3@v3.2.4/pkg/action/install.go:274
  13.   ...
  15.   Error: rendered manifests contain a resource that already exists. Unable to continue with install: ScopeDefinition "healthscopes.core.oam.dev" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; annotation validation error: key "meta.helm.sh/release-name" must equal "kubevela": current value is "oam"; annotation validation error: key "meta.helm.sh/release-namespace" must equal "vela-system": current value is "oam-system"

Delete ScopeDefinition “healthscopes.core.oam.dev” and try again.

  1. kubectl delete ScopeDefinition "healthscopes.core.oam.dev"
  1. scopedefinition.core.oam.dev "healthscopes.core.oam.dev" deleted
  1. vela install
  1. - Installing Vela Core Chart:
  3. install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  5. Successfully installed the chart, status: deployed, last deployed time = 2020-12-03 16:26:41.491426 +0800 CST m=+4.026069452
  7. WARN: handle workload template `containerizedworkloads.core.oam.dev` failed: no template found, you will unable to use this workload capabilityWARN: handle trait template `manualscalertraits.core.oam.dev` failed
  9. : no template found, you will unable to use this trait capabilityAutomatically discover capabilities successfully ✅ Add(8) Update(0) Delete(0)
  14. TYPE        CATEGORY    DESCRIPTION
  16. +task       workload    One-off task to run a piece of code or script to completion
  18. +webservice workload    Long-running scalable service with stable endpoint to receive external traffic
  20. +worker     workload    Long-running scalable backend worker without network endpoint
  22. +autoscale  trait       Automatically scale the app following certain triggers or metrics
  24. +metrics    trait       Configure metrics targets to be monitored for the app
  26. +rollout    trait       Configure canary deployment strategy to release the app
  28. +route      trait       Configure route policy to the app
  30. +scaler     trait       Manually scale the app
  35. - Finished successfully.

You have reached your pull rate limit

When you look into the logs of Pod kubevela-vela-core and found the issue as below.

  1. kubectl get pod -n vela-system -l app.kubernetes.io/name=vela-core
  1. NAME                                 READY   STATUS    RESTARTS   AGE
  3. kubevela-vela-core-f8b987775-wjg25   0/1     -         0          35m

Error response from daemon: toomanyrequests: You have reached your pull rate limit. You may increase the limit by authenticating and upgrading: https://www.docker.com/increase-rate-limit

You can use github container registry instead.

  1. docker pull ghcr.io/oam-dev/kubevela/vela-core:latest

Warning: Namespace cert-manager exists

If you hit the issue as below, an cert-manager release might exist whose namespace and RBAC related resource conflict with KubeVela.

  1. vela install
  1. - Installing Vela Core Chart:
  3. install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  5. Failed to install the chart with error: Namespace "cert-manager" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; label validation error: missing key "app.kubernetes.io/managed-by": must be set to "Helm"; annotation validation error: missing key "meta.helm.sh/release-name": must be set to "kubevela"; annotation validation error: missing key "meta.helm.sh/release-namespace": must be set to "vela-system"
  7. rendered manifests contain a resource that already exists. Unable to continue with install
  9. helm.sh/helm/v3/pkg/action.(*Install).Run
  11.         /home/runner/go/pkg/mod/helm.sh/helm/v3@v3.2.4/pkg/action/install.go:274
  13. ...
  15.         /opt/hostedtoolcache/go/1.14.12/x64/src/runtime/asm_amd64.s:1373
  17. Error: rendered manifests contain a resource that already exists. Unable to continue with install: Namespace "cert-manager" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; label validation error: missing key "app.kubernetes.io/managed-by": must be set to "Helm"; annotation validation error: missing key "meta.helm.sh/release-name": must be set to "kubevela"; annotation validation error: missing key "meta.helm.sh/release-namespace": must be set to "vela-system"

Try these steps to fix the problem.

  • Delete release cert-manager
  • Delete namespace cert-manager
  • Install KubeVela again
  1. helm delete cert-manager -n cert-manager
  1. release "cert-manager" uninstalled
  1. kubectl delete ns cert-manager
  1. namespace "cert-manager" deleted
  1. vela install
  1. - Installing Vela Core Chart:
  3. install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  5. Successfully installed the chart, status: deployed, last deployed time = 2020-12-04 10:46:46.782617 +0800 CST m=+4.248889379
  7. Automatically discover capabilities successfully ✅ (no changes)
  12. TYPE        CATEGORY    DESCRIPTION
  14. task        workload    One-off task to run a piece of code or script to completion
  16. webservice  workload    Long-running scalable service with stable endpoint to receive external traffic
  18. worker      workload    Long-running scalable backend worker without network endpoint
  20. autoscale   trait       Automatically scale the app following certain triggers or metrics
  22. metrics     trait       Configure metrics targets to be monitored for the app
  24. rollout     trait       Configure canary deployment strategy to release the app
  26. route       trait       Configure route policy to the app
  28. scaler      trait       Manually scale the app
  30. - Finished successfully.

How to fix issue: MutatingWebhookConfiguration mutating-webhook-configuration exists?

If you deploy some other services which will apply MutatingWebhookConfiguration mutating-webhook-configuration, installing KubeVela will hit the issue as below.

  1. - Installing Vela Core Chart:
  3. install chart vela-core, version v0.2.1, desc : A Helm chart for Kube Vela core, contains 36 file
  5. Failed to install the chart with error: MutatingWebhookConfiguration "mutating-webhook-configuration" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; label validation error: missing key "app.kubernetes.io/managed-by": must be set to "Helm"; annotation validation error: missing key "meta.helm.sh/release-name": must be set to "kubevela"; annotation validation error: missing key "meta.helm.sh/release-namespace": must be set to "vela-system"
  7. rendered manifests contain a resource that already exists. Unable to continue with install
  9. helm.sh/helm/v3/pkg/action.(*Install).Run
  11.     /home/runner/go/pkg/mod/helm.sh/helm/v3@v3.2.4/pkg/action/install.go:274
  13. github.com/oam-dev/kubevela/pkg/commands.InstallOamRuntime
  15.     /home/runner/work/kubevela/kubevela/pkg/commands/system.go:259
  17. github.com/oam-dev/kubevela/pkg/commands.(*initCmd).run
  19.     /home/runner/work/kubevela/kubevela/pkg/commands/system.go:162
  21. github.com/oam-dev/kubevela/pkg/commands.NewInstallCommand.func2
  23.     /home/runner/work/kubevela/kubevela/pkg/commands/system.go:119
  25. github.com/spf13/cobra.(*Command).execute
  27.     /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.1.1/command.go:850
  29. github.com/spf13/cobra.(*Command).ExecuteC
  31.     /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.1.1/command.go:958
  33. github.com/spf13/cobra.(*Command).Execute
  35.     /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.1.1/command.go:895
  37. main.main
  39.     /home/runner/work/kubevela/kubevela/references/cmd/cli/main.go:16
  41. runtime.main
  43.     /opt/hostedtoolcache/go/1.14.13/x64/src/runtime/proc.go:203
  45. runtime.goexit
  47.     /opt/hostedtoolcache/go/1.14.13/x64/src/runtime/asm_amd64.s:1373
  49. Error: rendered manifests contain a resource that already exists. Unable to continue with install: MutatingWebhookConfiguration "mutating-webhook-configuration" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; label validation error: missing key "app.kubernetes.io/managed-by": must be set to "Helm"; annotation validation error: missing key "meta.helm.sh/release-name": must be set to "kubevela"; annotation validation error: missing key "meta.helm.sh/release-namespace": must be set to "vela-system"

To fix this issue, please upgrade KubeVela Cli vela version to be higher than v0.2.2 from KubeVela releases.

Operating

Autoscale: how to enable metrics server in various Kubernetes clusters?

Operating Autoscale depends on metrics server, so it has to be enabled in various clusters. Please check whether metrics server is enabled with command kubectl top nodes or kubectl top pods.

If the output is similar as below, the metrics is enabled.

  1. kubectl top nodes
  1. NAME                     CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
  3. cn-hongkong.10.0.1.237   288m         7%     5378Mi          78%
  5. cn-hongkong.10.0.1.238   351m         8%     5113Mi          74%
  1. kubectl top pods
  1. NAME                          CPU(cores)   MEMORY(bytes)
  3. php-apache-65f444bf84-cjbs5   0m           1Mi
  5. wordpress-55c59ccdd5-lf59d    1m           66Mi

Or you have to manually enable metrics server in your Kubernetes cluster.

  • ACK (Alibaba Cloud Container Service for Kubernetes)

Metrics server is already enabled.

  • ASK (Alibaba Cloud Serverless Kubernetes)

Metrics server has to be enabled in Operations/Add-ons section of Alibaba Cloud console as below.

FAQ - 图1

Please refer to metrics server debug guide if you hit more issue.

  • Kind

Install metrics server as below, or you can install the latest version.

  1. kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.3.7/components.yaml

Also add the following part under .spec.template.spec.containers in the yaml file loaded by kubectl edit deploy -n kube-system metrics-server.

Noted: This is just a walk-around, not for production-level use.

  1. command:
  3. - /metrics-server
  5. - --kubelet-insecure-tls
  • MiniKube

Enable it with following command.

  1. minikube addons enable metrics-server

Have fun to set autoscale on your application.