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📖 cleanup: improves cronjob_controller_test.go gomega assertions (kub…
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…ernetes-sigs#4142)

Replaced some bespoke Eventually() signatures (e.g. func() bool and
func() (int, error)) with the standard func(g Gomega), allowing gomega
assertions to happen inside the Eventually().

Generally you _expect_ something _to_ happen
and _eventually_, something _should_ happen.

This is a part of kubernetes-sigs#4135
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@mogsie
mogsie authored Sep 8, 2024
1 parent e3ebfaf commit fa9f70c
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55 changes: 22 additions & 33 deletions ...book/src/cronjob-tutorial/testdata/project/internal/controller/cronjob_controller_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,8 +29,8 @@ import (
"reflect"
"time"

. "github.com/onsi/ginkgo/v2"
. "github.com/onsi/gomega"
. "github.com/onsi/ginkgo/v2"
. "github.com/onsi/gomega"
batchv1 "k8s.io/api/batch/v1"
v1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
Expand Down Expand Up @@ -96,14 +96,14 @@ var _ = Describe("CronJob controller", func() {
},
},
}
Expect(k8sClient.Create(ctx, cronJob)).Should(Succeed())
Expect(k8sClient.Create(ctx, cronJob)).To(Succeed())

/*
After creating this CronJob, let's check that the CronJob's Spec fields match what we passed in.
Note that, because the k8s apiserver may not have finished creating a CronJob after our `Create()` call from earlier, we will use Gomega’s Eventually() testing function instead of Expect() to give the apiserver an opportunity to finish creating our CronJob.
`Eventually()` will repeatedly run the function provided as an argument every interval seconds until
(a) the function’s output matches what’s expected in the subsequent `Should()` call, or
(a) the assertions done by the passed-in `Gomega` succeed, or
(b) the number of attempts * interval period exceed the provided timeout value.
In the examples below, timeout and interval are Go Duration values of our choosing.
Expand All @@ -113,12 +113,11 @@ var _ = Describe("CronJob controller", func() {
createdCronjob := &cronjobv1.CronJob{}

// We'll need to retry getting this newly created CronJob, given that creation may not immediately happen.
Eventually(func() bool {
err := k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)
return err == nil
}, timeout, interval).Should(BeTrue())
Eventually(func(g Gomega) {
g.Expect(k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)).To(Succeed())
}, timeout, interval).Should(Succeed())
// Let's make sure our Schedule string value was properly converted/handled.
Expect(createdCronjob.Spec.Schedule).Should(Equal("1 * * * *"))
Expect(createdCronjob.Spec.Schedule).To(Equal("1 * * * *"))
/*
Now that we've created a CronJob in our test cluster, the next step is to write a test that actually tests our CronJob controller’s behavior.
Let’s test the CronJob controller’s logic responsible for updating CronJob.Status.Active with actively running jobs.
Expand All @@ -128,13 +127,10 @@ var _ = Describe("CronJob controller", func() {
We use Gomega's `Consistently()` check here to ensure that the active job count remains 0 over a duration of time.
*/
By("By checking the CronJob has zero active Jobs")
Consistently(func() (int, error) {
err := k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)
if err != nil {
return -1, err
}
return len(createdCronjob.Status.Active), nil
}, duration, interval).Should(Equal(0))
Consistently(func(g Gomega) {
g.Expect(k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)).To(Succeed())
g.Expect(createdCronjob.Status.Active).To(HaveLen(0))
}, duration, interval).Should(Succeed())
/*
Next, we actually create a stubbed Job that will belong to our CronJob, as well as its downstream template specs.
We set the Job's status's "Active" count to 2 to simulate the Job running two pods, which means the Job is actively running.
Expand Down Expand Up @@ -171,31 +167,24 @@ var _ = Describe("CronJob controller", func() {

controllerRef := metav1.NewControllerRef(createdCronjob, gvk)
testJob.SetOwnerReferences([]metav1.OwnerReference{*controllerRef})
Expect(k8sClient.Create(ctx, testJob)).Should(Succeed())
// Note that you can not manage the status values while creating the resource.
// The status field is managed separately to reflect the current state of the resource.
Expect(k8sClient.Create(ctx, testJob)).To(Succeed())
// Note that you can not manage the status values while creating the resource.
// The status field is managed separately to reflect the current state of the resource.
// Therefore, it should be updated using a PATCH or PUT operation after the resource has been created.
// Additionally, it is recommended to use StatusConditions to manage the status. For further information see:
// Additionally, it is recommended to use StatusConditions to manage the status. For further information see:
// https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
testJob.Status.Active = 2
Expect(k8sClient.Status().Update(ctx, testJob)).Should(Succeed())
Expect(k8sClient.Status().Update(ctx, testJob)).To(Succeed())
/*
Adding this Job to our test CronJob should trigger our controller’s reconciler logic.
After that, we can write a test that evaluates whether our controller eventually updates our CronJob’s Status field as expected!
*/
By("By checking that the CronJob has one active Job")
Eventually(func() ([]string, error) {
err := k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)
if err != nil {
return nil, err
}

names := []string{}
for _, job := range createdCronjob.Status.Active {
names = append(names, job.Name)
}
return names, nil
}, timeout, interval).Should(ConsistOf(JobName), "should list our active job %s in the active jobs list in status", JobName)
Eventually(func(g Gomega) {
g.Expect(k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)).To(Succeed(), "should GET the CronJob")
g.Expect(createdCronjob.Status.Active).To(HaveLen(1), "should have exactly one active job")
g.Expect(createdCronjob.Status.Active[0].Name).To(Equal(JobName), "the wrong job is active")
}, timeout, interval).Should(Succeed(), "should list our active job %s in the active jobs list in status", JobName)
})
})

Expand Down
55 changes: 22 additions & 33 deletions hack/docs/internal/cronjob-tutorial/writing_tests_controller.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,8 +47,8 @@ import (
"reflect"
"time"
. "github.com/onsi/ginkgo/v2"
. "github.com/onsi/gomega"
. "github.com/onsi/ginkgo/v2"
. "github.com/onsi/gomega"
batchv1 "k8s.io/api/batch/v1"
v1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
Expand Down Expand Up @@ -114,15 +114,15 @@ var _ = Describe("CronJob controller", func() {
},
},
}
Expect(k8sClient.Create(ctx, cronJob)).Should(Succeed())
Expect(k8sClient.Create(ctx, cronJob)).To(Succeed())
/*
After creating this CronJob, let's check that the CronJob's Spec fields match what we passed in.
Note that, because the k8s apiserver may not have finished creating a CronJob after our` + " `" + `Create()` + "`" + ` call from earlier, we will use Gomega’s Eventually() testing function instead of Expect() to give the apiserver an opportunity to finish creating our CronJob.` + `
` +
"`" + `Eventually()` + "`" + ` will repeatedly run the function provided as an argument every interval seconds until
(a) the function’s output matches what’s expected in the subsequent` + " `" + `Should()` + "`" + ` call, or
(a) the assertions done by the passed-in ` + "`" + `Gomega` + "`" + ` succeed, or
(b) the number of attempts * interval period exceed the provided timeout value.
In the examples below, timeout and interval are Go Duration values of our choosing.
Expand All @@ -132,12 +132,11 @@ var _ = Describe("CronJob controller", func() {
createdCronjob := &cronjobv1.CronJob{}
// We'll need to retry getting this newly created CronJob, given that creation may not immediately happen.
Eventually(func() bool {
err := k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)
return err == nil
}, timeout, interval).Should(BeTrue())
Eventually(func(g Gomega) {
g.Expect(k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)).To(Succeed())
}, timeout, interval).Should(Succeed())
// Let's make sure our Schedule string value was properly converted/handled.
Expect(createdCronjob.Spec.Schedule).Should(Equal("1 * * * *"))
Expect(createdCronjob.Spec.Schedule).To(Equal("1 * * * *"))
/*
Now that we've created a CronJob in our test cluster, the next step is to write a test that actually tests our CronJob controller’s behavior.
Let’s test the CronJob controller’s logic responsible for updating CronJob.Status.Active with actively running jobs.
Expand All @@ -147,13 +146,10 @@ var _ = Describe("CronJob controller", func() {
We use Gomega's` + " `" + `Consistently()` + "`" + ` check here to ensure that the active job count remains 0 over a duration of time.
*/
By("By checking the CronJob has zero active Jobs")
Consistently(func() (int, error) {
err := k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)
if err != nil {
return -1, err
}
return len(createdCronjob.Status.Active), nil
}, duration, interval).Should(Equal(0))
Consistently(func(g Gomega) {
g.Expect(k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)).To(Succeed())
g.Expect(createdCronjob.Status.Active).To(HaveLen(0))
}, duration, interval).Should(Succeed())
/*
Next, we actually create a stubbed Job that will belong to our CronJob, as well as its downstream template specs.
We set the Job's status's "Active" count to 2 to simulate the Job running two pods, which means the Job is actively running.
Expand Down Expand Up @@ -190,31 +186,24 @@ var _ = Describe("CronJob controller", func() {
controllerRef := metav1.NewControllerRef(createdCronjob, gvk)
testJob.SetOwnerReferences([]metav1.OwnerReference{*controllerRef})
Expect(k8sClient.Create(ctx, testJob)).Should(Succeed())
// Note that you can not manage the status values while creating the resource.
// The status field is managed separately to reflect the current state of the resource.
Expect(k8sClient.Create(ctx, testJob)).To(Succeed())
// Note that you can not manage the status values while creating the resource.
// The status field is managed separately to reflect the current state of the resource.
// Therefore, it should be updated using a PATCH or PUT operation after the resource has been created.
// Additionally, it is recommended to use StatusConditions to manage the status. For further information see:
// Additionally, it is recommended to use StatusConditions to manage the status. For further information see:
// https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/api-conventions.md#spec-and-status
testJob.Status.Active = 2
Expect(k8sClient.Status().Update(ctx, testJob)).Should(Succeed())
Expect(k8sClient.Status().Update(ctx, testJob)).To(Succeed())
/*
Adding this Job to our test CronJob should trigger our controller’s reconciler logic.
After that, we can write a test that evaluates whether our controller eventually updates our CronJob’s Status field as expected!
*/
By("By checking that the CronJob has one active Job")
Eventually(func() ([]string, error) {
err := k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)
if err != nil {
return nil, err
}
names := []string{}
for _, job := range createdCronjob.Status.Active {
names = append(names, job.Name)
}
return names, nil
}, timeout, interval).Should(ConsistOf(JobName), "should list our active job %s in the active jobs list in status", JobName)
Eventually(func(g Gomega) {
g.Expect(k8sClient.Get(ctx, cronjobLookupKey, createdCronjob)).To(Succeed(), "should GET the CronJob")
g.Expect(createdCronjob.Status.Active).To(HaveLen(1), "should have exactly one active job")
g.Expect(createdCronjob.Status.Active[0].Name).To(Equal(JobName), "the wrong job is active")
}, timeout, interval).Should(Succeed(), "should list our active job %s in the active jobs list in status", JobName)
})
})
Expand Down

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