invalid type for io.x-k8s.cluster.infrastructure.v1alpha3.AWSMachinePool.spec.subnets: got "string", expected "map"

[chessman]

/kind bug

What steps did you take and what happened:

I followed steps from https://cluster-api-aws.sigs.k8s.io/topics/machinepools.html

apiVersion: infrastructure.cluster.x-k8s.io/v1alpha3
kind: AWSMachinePool
metadata:
  name: capi-test-mp-0
  namespace: default
spec:
  availabilityZones:
  - "eu-central-1"
  awsLaunchTemplate:
    instanceType: t3.large
    sshKeyName: capi
  maxSize: 10
  minSize: 1
  subnets:
    - "eu-central-1a"

After applying the configuration, I got

error validating "capi-test.yaml": error validating data: ValidationError(AWSMachinePool.spec.subnets[0]): invalid type for io.x-k8s.cluster.infrastructure.v1alpha3.AWSMachinePool.spec.subnets: got "string", expected "map"; if you choose to ignore these errors, turn validation off with --validate=false

What did you expect to happen:

No error as it is the same as in the provided documentation.

Anything else you would like to add:

This configuration works:

subnets:
  - id: eu-central-1a

Subnets field has []infrav1.AWSResourceReference type, so it requires an object, not a string.

Environment:

• Cluster-api-provider-aws version: v0.6.6
• Kubernetes version: (use kubectl version): v1.21.1
• OS (e.g. from /etc/os-release): Debian GNU/Linux 11 (bullseye)

[sedefsavas]

Thanks for reporting. This is a documentation issue not a bug I think. Contributions are welcome as well.

/milestone Next
/kind documentation

[chessman]

@sedefsavas I continued configuring the cluster and got an error

    Message:               failed to create AWSMachinePool: failed to create autoscaling group: ValidationError: The subnet ID 'eu-central-1a' does not exist
                           status code: 400, request id: 7f6e0e3b-8cca-4c31-ab11-79367adcd946

It means that "id: eu-central-1a" is also not a proper configuration. I replaced it with a subnet ID (subnet-xxxxxxxxx) and it worked out. But this ID gets known after the cluster is provisioned, so it's impossible to specify it beforehand.

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/lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues and PRs according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

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/lifecycle rotten

[shivi28]

When we apply cluster-template-machinepool.yaml then it's not mandatory to provide subnet field and perhaps it's useful if we want to use any existing subnet.
IMO we can remove this subnet field from template flavour and documentation .
Wanted to know your thoughts @sedefsavas ?

[shivi28]

/lifecycle active

[sedefsavas]

/triage accepted

[sedefsavas]

@shivi28
Let's keep the subnets in the documentation only. This issue is created because we had no correct example on defining subnets in MachinePools.

[sedefsavas]

/priority backlog

[sedefsavas]

I think you forgot to assign yourself.
/assign @shivi28

[shivi28]

Thanks @sedefsavas, I have updated the template and doc

[sedefsavas]

Since this is documentation, I am bumping the milestone to the next release.
/milestone v1.2.0