Generating CronTab CustomResources with crd2pulumi

This example lives in the pulumi/examples repository. Check out just this directory to use it:

$ git clone --filter=blob:none --sparse https://github.com/pulumi/examples pulumi-examples
$ git -C pulumi-examples sparse-checkout set crd2pulumi-crontabs
$ cd pulumi-examples/crd2pulumi-crontabs

This example generates a strongly-typed CronTab CustomResource from the Kubernetes CRD specified in crontabs.yaml in TypeScript and Go. Afterwards, we’ll use this generated code with Pulumi to deploy the CRD and create an instance. For more documentation on crd2pulumi, check out the project’s GitHub page.

Setting up crd2pulumi#

We’ll set up crd2pulumi by downloading the latest binary. If you’re interested in building crd2pulumi itself, you can find instructions in the project README.

You can find the download links for the latest binaries on GitHub. For this example we’re using darwin-amd64, so if you’re using a different OS, make sure to use the correct download link.

$ wget https://github.com/pulumi/pulumi-kubernetes/releases/download/crd2pulumi%2Fv1.0.0/crd2pulumi-darwin-amd64.tar.gz
$ tar -xvf crd2pulumi-darwin-amd64.tar.gz
$ mv ./releases/crd2pulumi-darwin-amd64/crd2pulumi ./crd2pulumi

Running the App (TypeScript)#

Follow the steps in Pulumi Installation and Setup and Configuring Pulumi Kubernetes to get setup with Pulumi and Kubernetes.

Install dependencies:

$ cd kubernetes-ts-crontabs
$ npm install

Create a new stack:

$ pulumi stack init dev

At first, the provided index.ts program shouldn’t run, since we haven’t actually generated the ./crontabs code yet.

crontabs.yaml is a k8s CRD that specifies a CronTab CustomResource. It’s also used as an example in the Kubernetes Documentation.

Generate the strongly-typed CronTab resource in the current directory:

$ ../crd2pulumi nodejs ../crontabs.yaml .

This should generate a ./crontabs folder, where we can import the useful classes v1.CronTab and NewCronTabDefinition.

This saves us a lot of time, since we can create the CRD in a single line and get typed arguments in the CustomResource. If you’re curious, the comments contain the code that we would’ve written without crd2pulumi.

Perform the deployment:

$ pulumi up
Previewing update (dev):
   Type                                                       Name                 Plan
   pulumi:pulumi:Stack                                        examples-dev
 +   ├─ kubernetes:stable.example.com:CronTab                   my-new-cron-object   create
 +   └─ kubernetes:apiextensions.k8s.io:CustomResourceDefinition  my-crontab-definition  create
Resources:
  + 2 to create
  1 unchanged
Do you want to perform this update? yes
Updating (dev):
   Type                                                       Name                 Status
   pulumi:pulumi:Stack                                        examples-dev
 +   ├─ kubernetes:stable.example.com:CronTab                   my-new-cron-object   created
 +   └─ kubernetes:apiextensions.k8s.io:CustomResourceDefinition  my-crontab-definition  created
Outputs:
  urn: "urn:pulumi:dev::examples::kubernetes:stable.example.com/v1:CronTab::my-new-cron-object"
Resources:
  + 2 created
  1 unchanged
Duration: 17s

It looks like both the CronTab definition and instance were both created! Finally, let’s verify that they were created by manually viewing the raw YAML data:

$ kubectl get ct -o yaml

- apiVersion: stable.example.com/v1
  kind: CronTab
  metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"stable.example.com/v1","kind":"CronTab","metadata":{"labels":{"app.kubernetes.io/managed-by":"pulumi"},"name":"my-new-cron-object"},"spec":{"cronSpec":"* * * * */5","image":"my-awesome-cron-image"}}
  creationTimestamp: "2020-08-10T09:50:38Z"
  generation: 1
  labels:
    app.kubernetes.io/managed-by: pulumi
  name: my-new-cron-object
  namespace: default
  resourceVersion: "1658962"
  selfLink: /apis/stable.example.com/v1/namespaces/default/crontabs/my-new-cron-object
  uid: 5e2c56a2-7332-49cf-b0fc-211a0892c3d5
  spec:
  cronSpec: '* * * * */5'
  image: my-awesome-cron-image
kind: List
metadata:
  resourceVersion: ""
  selfLink: ""

Let’s destroy the CRD and CustomResource object so we can re-create them in Go.

$ pulumi destroy
Previewing destroy (dev):
     Type                                                         Name                        Plan
 -   pulumi:pulumi:Stack                                          kubernetes-go-crontabs-dev  delete
 -   ├─ kubernetes:stable.example.com:CronTab                     my-new-cron-object          delete
 -   └─ kubernetes:apiextensions.k8s.io:CustomResourceDefinition  cronTabDef                  delete

Outputs:
  - urn: "urn:pulumi:dev::kubernetes-go-crontabs::kubernetes:stable.example.com/v1:CronTab::my-new-cron-object"

Resources:
    - 3 to delete

Do you want to perform this destroy? yes
Destroying (dev):
     Type                                                         Name                        Status
 -   pulumi:pulumi:Stack                                          kubernetes-go-crontabs-dev  deleted
 -   ├─ kubernetes:stable.example.com:CronTab                     my-new-cron-object          deleted
 -   └─ kubernetes:apiextensions.k8s.io:CustomResourceDefinition  cronTabDef                  deleted

Outputs:
  - urn: "urn:pulumi:dev::kubernetes-go-crontabs::kubernetes:stable.example.com/v1:CronTab::my-new-cron-object"

Resources:
    - 3 deleted

Duration: 5s

The resources in the stack have been deleted, but the history and configuration associated with the stack are still maintained.
If you want to remove the stack completely, run 'pulumi stack rm dev'.

Running the App (Go)#

First, if you haven’t already, install Go. Then create a new stack:

$ cd kubernetes-go-crontabs
$ pulumi stack init dev

Like before, main.go shouldn’t compile since we haven’t generated the crontabs module yet. Let’s do that:

$ ../crd2pulumi go ../crontabs.yaml .

This creates a crontabs/v1 module in the current directory, which contains the useful constructor NewCronTab().

If you’re curious, the commented code is what we would’ve had to write without crd2pulumi. Previously we would have had to input the Spec arguments into a generic map[string]interface{} with zero type-checking.

Perform the deployment:

$ pulumi up --yes
Previewing update (dev):
     Type                                                         Name                        Plan
 +   pulumi:pulumi:Stack                                          kubernetes-go-crontabs-dev  create
 +   ├─ kubernetes:stable.example.com:CronTab                     my-new-cron-object          create
 +   └─ kubernetes:apiextensions.k8s.io:CustomResourceDefinition  cronTabDef                  create

Resources:
    + 3 to create

Updating (dev):
     Type                                                         Name                        Status
 +   pulumi:pulumi:Stack                                          kubernetes-go-crontabs-dev  created
 +   ├─ kubernetes:stable.example.com:CronTab                     my-new-cron-object          created
 +   └─ kubernetes:apiextensions.k8s.io:CustomResourceDefinition  cronTabDef                  created

Outputs:
    urn: "urn:pulumi:dev::kubernetes-go-crontabs::kubernetes:stable.example.com/v1:CronTab::my-new-cron-object"

Resources:
    + 3 created

Duration: 10s

Like before, you can run kubectl get ct -o yaml to verify that the CronTab object was actually created. Before we leave, let’s remove everything we have created:

$ pulumi destroy --yes
Previewing destroy (dev):
     Type                                                         Name                        Plan
 -   pulumi:pulumi:Stack                                          kubernetes-go-crontabs-dev  delete
 -   ├─ kubernetes:stable.example.com:CronTab                     my-new-cron-object          delete
 -   └─ kubernetes:apiextensions.k8s.io:CustomResourceDefinition  cronTabDef                  delete

Outputs:
  - urn: "urn:pulumi:dev::kubernetes-go-crontabs::kubernetes:stable.example.com/v1:CronTab::my-new-cron-object"

Resources:
    - 3 to delete

Destroying (dev):
     Type                                                         Name                        Status
 -   pulumi:pulumi:Stack                                          kubernetes-go-crontabs-dev  deleted
 -   ├─ kubernetes:stable.example.com:CronTab                     my-new-cron-object          deleted
 -   └─ kubernetes:apiextensions.k8s.io:CustomResourceDefinition  cronTabDef                  deleted

Outputs:
  - urn: "urn:pulumi:dev::kubernetes-go-crontabs::kubernetes:stable.example.com/v1:CronTab::my-new-cron-object"

Resources:
    - 3 deleted

Duration: 3s

Setting up crd2pulumi#

Running the App (TypeScript)#

Running the App (Go)#

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