README.md

Prerequisites

• go
• kubectl logged into a Kubernetes cluster.
• Each scaler test might define additional requirements. For example, azure_queue_test.go requires an env var AZURE_STORAGE_CONNECTION_STRING

Running tests:

All tests

go test -v setup_test.go        # Only needs to be run once.
go test -v ./scalers_go/...
go test -v cleanup_test.go      # Skip if you want to keep testing.

Specific test

go test -v ./scalers_go/azure_queue/azure_queue_test.go # Assumes that setup has been run before

Refer to this for more information about testing in Go.

E2E Test Setup

The test script will run in 3 phases:

• Setup: This is done in setup_test.go. If you're adding any tests to the KEDA install / setup process, you need to add it to this file. setup_test.go deploys KEDA to the keda namespace, updates the image to kedacore/keda:main.

  After setup_test.go is done, we expect to have KEDA setup in the keda namespace.

• Tests: Currently there are only scaler tests in tests/scalers_go/. Each test is kept in its own package. This is to prevent conflicting variable declarations for commoly used variables (ex - testNamespace). Individual scaler tests are run in parallel, but tests within a file can be run in parallel or in series. More about tests below.

• Global cleanup: This is done in cleanup_test.go. It cleans up all the resources created in setup_test.go.

Adding tests

• Tests are written using Go's default testing framework, and testify.
• Each scaler should be in its own package, ex - scalers_go/azure_queue/azure_queue_test.go, or scalers_go/kafka/kafka_test.go, etc
• Each test file is expected to do its own setup and clean for resources.

⚠⚠ Important: ⚠⚠

• Even though the cleaning of resources is expected inside each e2e test file, all test namespaces (namespaces with label type=e2e) are cleaned up to ensure not having dangling resources after global e2e execution finishes. To not break this behaviour, it's mandatory to use the CreateNamespace(t *testing.T, kc *kubernetes.Clientset, nsName string) function from helper.go, instead of creating them manually.

⚠⚠ Important: ⚠⚠

• Go code can panic when performing forbidden operations such as accessing a nil pointer, or from code that manually calls panic(). A function that panics passes the panic up the stack until program execution stops or it is recovered using recover() (somewhat similar to try-catch in other languages).
• If a test panics, and is not recovered, Go will stop running the file, and no further tests will be run. This can cause issues with clean up of resources.
• Ensure that you are not executing code that can lead to panics. If you think that there's a chance the test might panic, call recover(), and cleanup the created resources.
• Read this article for understanding more about panic and recover in Go.

Example Test: Let's say you want to add a test for Redis.

// +build e2e
// ^ This is necessary to ensure the tests don't get run in the GitHub workflow.
import (
	"context"
	"fmt"
	"os"
	"testing"

	"github.com/joho/godotenv"
	"github.com/stretchr/testify/require"
    // Other required imports
    ...
    ...

	. "github.com/kedacore/keda/v2/tests/helper" // For helper methods
)

var _ = godotenv.Load("../../.env") // For loading env variables from .env

const (
    testName = "redis-test"
    // Other constants required for your test
    ...
    ...
)

var (
    testNamespace    = fmt.Sprintf("%s-ns", testName)
    // Other variables required for your test
    ...
    ...
)

// YAML templates for your Kubernetes resources
const (
    deploymentTemplate = `
apiVersion: apps/v1
kind: Deployment
metadata:
  name: test-deployment
  labels:
    app: test-deployment
spec:
  replicas: 0
  ...
  ...
`
...
...
)

type templateData struct {
    // Fields used in your Kubernetes YAML templates
    ...
    ...
}

func TestScaler(t *testing.T) {
    setupTest(t)

    kc := GetKubernetesClient(t)
    data, templates := getTemplateData()

    CreateKubernetesResources(t, kc, testNamespace, data, templates...)

    testScaleUp(t)

    // Ensure that this gets run. Using defer is necessary
    DeleteKubernetesResources(t, kc, testNamespace, data, templates...)
    cleanupTest(t)
}

func setupTest(t *testing.T) {
    t.Log("--- setting up ---")
    _, err := ParseCommand("which helm").Output()
    assert.NoErrorf(t, err, "redis test requires helm - %s", err)

    _, err := ParseCommand("helm install redis .....").Output()
    assert.NoErrorf(t, err, "error while installing redis - %s", err)
}

func getTemplateData() (templateData, []string) {
    return templateData{
        // Populate fields required in YAML templates
        ...
        ...
    }, []string{deploymentTemplate, scaledObjectTemplate}
}

func testScaleUp(t *testing.T, kc *kubernetes.Clientset) {
    t.Log("--- testing scale up ---")
    // Use Go Redis Library to add stuff to redis to trigger scale up.
    ...
    ...
    // Sleep / poll for replica count using helper method.
    require.True(t, WaitForDeploymentReplicaCount(t, kc, deploymentName, testNamespace, 10, 60, 1),
		"replica count should be 10 after 1 minute")
}

func cleanupTest(t *testing.T) {
    t.Log("--- cleaning up ---")
    // Cleanup external resources (such as Blob Storage Container, RabbitMQ queue, Redis in this case)
    ...
    ...
}

Notes

• You can see azure_queue_test.go for a full example.
• All tests must have the // +build e2e build tag.
• Refer helper.go for various helper methods available to use in your tests.
• Prefer using helper methods or k8s libraries in Go over manually executing shell commands. Only if the task you're trying to achieve is too complicated or tedious using above, use ParseCommand or ExecuteCommand from helper.go for executing shell commands.
• Ensure, ensure, ensure that you're cleaning up resources.
• You can use VS Code for easily debugging your tests.