Version: v1.1

FAQ

Compare to X

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:
  2. install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  3. 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
  4. failed to create resource
  5. helm.sh/helm/v3/pkg/kube.(*Client).Update.func1
  6.     /home/runner/go/pkg/mod/helm.sh/helm/v3@v3.2.4/pkg/kube/client.go:190
  7. ...
  8. 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:
  2. Vela system along with OAM runtime already exist.
  3. Automatically discover capabilities successfully ✅ Add(0) Update(0) Delete(8)
  6. TYPE        CATEGORY    DESCRIPTION
  7. -task       workload    One-off task to run a piece of code or script to completion
  8. -webservice workload    Long-running scalable service with stable endpoint to receive external traffic
  9. -worker     workload    Long-running scalable backend worker without network endpoint
  10. -autoscale  trait       Automatically scale the app following certain triggers or metrics
  11. -metrics    trait       Configure metrics targets to be monitored for the app
  12. -rollout    trait       Configure canary deployment strategy to release the app
  13. -route      trait       Configure route policy to the app
  14. -scaler     trait       Manually scale the app
  17. - Finished successfully.

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

  1. kubectl apply -f charts/vela-core/templates/defwithtemplate
  1. traitdefinition.core.oam.dev/autoscale created
  2. traitdefinition.core.oam.dev/scaler created
  3. traitdefinition.core.oam.dev/metrics created
  4. traitdefinition.core.oam.dev/rollout created
  5. traitdefinition.core.oam.dev/route created
  6. workloaddefinition.core.oam.dev/task created
  7. workloaddefinition.core.oam.dev/webservice created
  8. workloaddefinition.core.oam.dev/worker created
  1. vela workloads
  1. Automatically discover capabilities successfully ✅ Add(8) Update(0) Delete(0)
  4. TYPE        CATEGORY    DESCRIPTION
  5. +task       workload    One-off task to run a piece of code or script to completion
  6. +webservice workload    Long-running scalable service with stable endpoint to receive external traffic
  7. +worker     workload    Long-running scalable backend worker without network endpoint
  8. +autoscale  trait       Automatically scale the app following certain triggers or metrics
  9. +metrics    trait       Configure metrics targets to be monitored for the app
  10. +rollout    trait       Configure canary deployment strategy to release the app
  11. +route      trait       Configure route policy to the app
  12. +scaler     trait       Manually scale the app
  15. NAME        DESCRIPTION
  16. task        One-off task to run a piece of code or script to completion
  17. webservice  Long-running scalable service with stable endpoint to receive external traffic
  18. 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:
  2.   install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  3.   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"
  4.   rendered manifests contain a resource that already exists. Unable to continue with install
  5.   helm.sh/helm/v3/pkg/action.(*Install).Run
  6.     /home/runner/go/pkg/mod/helm.sh/helm/v3@v3.2.4/pkg/action/install.go:274
  7.   ...
  8.   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:
  2. install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  3. Successfully installed the chart, status: deployed, last deployed time = 2020-12-03 16:26:41.491426 +0800 CST m=+4.026069452
  4. 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
  5. : no template found, you will unable to use this trait capabilityAutomatically discover capabilities successfully ✅ Add(8) Update(0) Delete(0)
  8. TYPE        CATEGORY    DESCRIPTION
  9. +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
  11. +worker     workload    Long-running scalable backend worker without network endpoint
  12. +autoscale  trait       Automatically scale the app following certain triggers or metrics
  13. +metrics    trait       Configure metrics targets to be monitored for the app
  14. +rollout    trait       Configure canary deployment strategy to release the app
  15. +route      trait       Configure route policy to the app
  16. +scaler     trait       Manually scale the app
  19. - 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
  2. 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:
  2. install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  3. 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"
  4. rendered manifests contain a resource that already exists. Unable to continue with install
  5. helm.sh/helm/v3/pkg/action.(*Install).Run
  6.         /home/runner/go/pkg/mod/helm.sh/helm/v3@v3.2.4/pkg/action/install.go:274
  7. ...
  8.         /opt/hostedtoolcache/go/1.14.12/x64/src/runtime/asm_amd64.s:1373
  9. 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:
  2. install chart vela-core, version 0.1.0, desc : A Helm chart for Kube Vela core, contains 35 file
  3. Successfully installed the chart, status: deployed, last deployed time = 2020-12-04 10:46:46.782617 +0800 CST m=+4.248889379
  4. Automatically discover capabilities successfully ✅ (no changes)
  7. TYPE        CATEGORY    DESCRIPTION
  8. task        workload    One-off task to run a piece of code or script to completion
  9. webservice  workload    Long-running scalable service with stable endpoint to receive external traffic
  10. worker      workload    Long-running scalable backend worker without network endpoint
  11. autoscale   trait       Automatically scale the app following certain triggers or metrics
  12. metrics     trait       Configure metrics targets to be monitored for the app
  13. rollout     trait       Configure canary deployment strategy to release the app
  14. route       trait       Configure route policy to the app
  15. scaler      trait       Manually scale the app
  16. - 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:
  2. install chart vela-core, version v0.2.1, desc : A Helm chart for Kube Vela core, contains 36 file
  3. 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"
  4. rendered manifests contain a resource that already exists. Unable to continue with install
  5. helm.sh/helm/v3/pkg/action.(*Install).Run
  6.     /home/runner/go/pkg/mod/helm.sh/helm/v3@v3.2.4/pkg/action/install.go:274
  7. github.com/oam-dev/kubevela/pkg/commands.InstallOamRuntime
  8.     /home/runner/work/kubevela/kubevela/pkg/commands/system.go:259
  9. github.com/oam-dev/kubevela/pkg/commands.(*initCmd).run
  10.     /home/runner/work/kubevela/kubevela/pkg/commands/system.go:162
  11. github.com/oam-dev/kubevela/pkg/commands.NewInstallCommand.func2
  12.     /home/runner/work/kubevela/kubevela/pkg/commands/system.go:119
  13. github.com/spf13/cobra.(*Command).execute
  14.     /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.1.1/command.go:850
  15. github.com/spf13/cobra.(*Command).ExecuteC
  16.     /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.1.1/command.go:958
  17. github.com/spf13/cobra.(*Command).Execute
  18.     /home/runner/go/pkg/mod/github.com/spf13/cobra@v1.1.1/command.go:895
  19. main.main
  20.     /home/runner/work/kubevela/kubevela/references/cmd/cli/main.go:16
  21. runtime.main
  22.     /opt/hostedtoolcache/go/1.14.13/x64/src/runtime/proc.go:203
  23. runtime.goexit
  24.     /opt/hostedtoolcache/go/1.14.13/x64/src/runtime/asm_amd64.s:1373
  25. 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%
  2. cn-hongkong.10.0.1.237   288m         7%     5378Mi          78%
  3. cn-hongkong.10.0.1.238   351m         8%     5113Mi          74%
  1. kubectl top pods
  1. NAME                          CPU(cores)   MEMORY(bytes)
  2. php-apache-65f444bf84-cjbs5   0m           1Mi
  3. 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:
  2. - /metrics-server
  3. - --kubelet-insecure-tls
  • MiniKube

Enable it with following command.

  1. minikube addons enable metrics-server

Have fun to set autoscale on your application.