[chore] document local e2e test execution, minor tweaks to tests (#222)

Signed-off-by: Florian Bacher <florian.bacher@dynatrace.com>
Co-authored-by: Moritz Wiesinger <moritz.wiesinger@dynatrace.com>

internal/k8stest/client.go

@@ -6,6 +6,7 @@ package k8stest // import "github.com/open-telemetry/opentelemetry-collector-con
 import (
 	"errors"
 	"fmt"
+	"os"
 
 	"k8s.io/client-go/discovery"
 	memory "k8s.io/client-go/discovery/cached"
@@ -14,13 +15,24 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 )
 
+const (
+	testKubeConfig   = "/tmp/kube-config-collector-e2e-testing"
+	kubeConfigEnvVar = "KUBECONFIG"
+)
+
 type K8sClient struct {
 	DynamicClient   *dynamic.DynamicClient
 	DiscoveryClient *discovery.DiscoveryClient
 	Mapper          *restmapper.DeferredDiscoveryRESTMapper
 }
 
-func NewK8sClient(kubeconfigPath string) (*K8sClient, error) {
+func NewK8sClient() (*K8sClient, error) {
+
+	kubeconfigPath := testKubeConfig
+
+	if kubeConfigFromEnv := os.Getenv(kubeConfigEnvVar); kubeConfigFromEnv != "" {
+		kubeconfigPath = kubeConfigFromEnv
+	}
 
 	if kubeconfigPath == "" {
 		return nil, errors.New("Please provide file path to load kubeconfig")

internal/k8stest/k8s_collector.go

@@ -34,9 +34,10 @@ func CreateCollectorObjects(t *testing.T, client *K8sClient, testID string, mani
 		tmpl := template.Must(template.New(manifestFile.Name()).ParseFiles(filepath.Join(manifestsDir, manifestFile.Name())))
 		manifest := &bytes.Buffer{}
 		require.NoError(t, tmpl.Execute(manifest, map[string]string{
-			"Name":         "otelcol-" + testID,
-			"HostEndpoint": host,
-			"TestID":       testID,
+			"Name":              "otelcol-" + testID,
+			"HostEndpoint":      host,
+			"TestID":            testID,
+			"ContainerRegistry": os.Getenv("CONTAINER_REGISTRY"),
 		}))
 		obj, err := CreateObject(client, manifest.Bytes())
 		require.NoErrorf(t, err, "failed to create collector object from manifest %s", manifestFile.Name())

internal/testbed/integration/k8senrichment/README.md

@@ -5,7 +5,7 @@ This is the e2e test for the Collector use-case:
 
 ## Requirements to run the tests
 
-- Docker
+- Docker or Podman
 - Kind
 
 The tests require a running Kind k8s cluster. During the tests,
@@ -15,3 +15,77 @@ on the k8s cluster with configurations as per the Dynatrace documentation page.
 Traces are generated and sent to the Collector, which then
 exports to the test where the k8s attributes are asserted on the
 received traces.
+
+## Running the tests locally
+
+To execute the tests locally, follow these steps:
+
+### Start a `kind` cluster
+
+To create a new cluster, execute the following command:
+
+```shell
+kind create cluster
+```
+### Build the collector binary
+
+This is done using the `make build` command.
+This will build the collector distro, and place the built binary 
+into the `bin` directory of your local copy of the repository.
+
+**NOTE:** When using an M1 mac, the `make build` command will build the `arm64` binary, which
+will not be able to run as a container on a `kind` cluster.
+For now, as workaround you will need to use the `make build-all` command to build all binaries and then copy the
+`linux_amd64` binary from the `dist` directory into `bin` under the name `dynatrace-otel-collector`.
+
+### Build the container
+
+From the `bin` directory, use `docker` or `podman` to build the collector image, and to load the built
+image into the local registry of the `kind` cluster.
+
+Note that this process differs between `podman` and `docker`, as with `podman`, you will have to
+load the image using the `image-archive` argument:
+
+**Build and load with `podman`:**
+```shell
+cd bin
+podman buildx build -t dynatrace-otel-collector:e2e-test -f ../Dockerfile . --load
+podman save -o dynatrace-otel-collector.tar dynatrace-otel-collector:e2e-test
+kind load image-archive dynatrace-otel-collector.tar --name kind
+cd ..
+```
+
+**Build and load with `docker`:**
+```shell
+cd bin
+docker buildx build -t dynatrace-otel-collector:e2e-test -f ../Dockerfile . --load
+docker save -o dynatrace-otel-collector.tar dynatrace-otel-collector:e2e-test
+kind load docker-image dynatrace-otel-collector:e2e-test --name kind
+cd ..
+```
+
+### Running the tests
+
+After the above steps are completed, the E2E tests can be run.
+
+Note that the tests will, by default, use the following `kubeconfig` path: `/tmp/kube-config-collector-e2e-testing`.
+This path can be modified by setting the `KUBECONFIG` environment variable (in case you have a local kind cluster with the
+kube config located in `~/.kube.config`).
+Also, if you are using `podman`, the collector image will be prefixed with `localhost/` within the local
+`kind` registry. In this case, you will need to set the `CONTAINER_REGISTRY` to `localhost/`.
+When using `docker`, setting the `CONTAINER_REGISTRY` env var is not required.
+Below are the commands to execute the `k8senrichment` e2e test:
+
+** Using podman:**
+```shell
+cd internal/testbed/integration/k8senrichment
+KUBECONFIG="~/.kube/config" CONTAINER_REGISTRY="localhost/" go test -v --tags=e2e
+```
+
+** Using docker:**
+```shell
+cd internal/testbed/integration/k8senrichment
+KUBECONFIG="/Users/my-user/.kube/config" go test -v --tags=e2e
+```
+
+

internal/testbed/integration/k8senrichment/e2e_test.go

@@ -28,8 +28,7 @@ const (
 	equal = iota
 	regex
 	exist
-	testKubeConfig = "/tmp/kube-config-collector-e2e-testing"
-	uidRe          = "[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}"
+	uidRe = "[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}"
 )
 
 type expectedValue struct {
@@ -49,7 +48,7 @@ func newExpectedValue(mode int, value string) *expectedValue {
 func TestE2E_ClusterRBAC(t *testing.T) {
 	testDir := filepath.Join("testdata")
 
-	k8sClient, err := k8stest.NewK8sClient(testKubeConfig)
+	k8sClient, err := k8stest.NewK8sClient()
 	require.NoError(t, err)
 
 	// Create the namespace specific for the test

internal/testbed/integration/k8senrichment/testdata/collector/deployment.yaml

@@ -21,7 +21,7 @@ spec:
           command:
             - /dynatrace-otel-collector
             - --config=/conf/relay.yaml
-          image: "dynatrace-otel-collector:e2e-test"
+          image: "{{ .ContainerRegistry }}dynatrace-otel-collector:e2e-test"
           ports:
             - name: otlp
               containerPort: 4317

internal/testbed/integration/prometheus/e2e_test.go

@@ -33,7 +33,7 @@ const (
 func TestE2E_PrometheusNodeExporter(t *testing.T) {
 	testDir := filepath.Join("testdata")
 
-	k8sClient, err := k8stest.NewK8sClient(testKubeConfig)
+	k8sClient, err := k8stest.NewK8sClient()
 	require.NoError(t, err)
 
 	// Create the namespace specific for the test

internal/testbed/integration/prometheus/testdata/collector/deployment.yaml

@@ -21,7 +21,7 @@ spec:
           command:
             - /dynatrace-otel-collector
             - --config=/conf/relay.yaml
-          image: "dynatrace-otel-collector:e2e-test"
+          image: "{{ .ContainerRegistry }}dynatrace-otel-collector:e2e-test"
           ports:
             - name: otlp
               containerPort: 4317