test(e2e): always generate test ID in test, not in the app under test

This solves an issue where the test suite would read an outdated test ID
from disk for cronjobs and fail to match cronjob spans.

test-resources/node.js/express/app.js

@@ -1,8 +1,6 @@
 // SPDX-FileCopyrightText: Copyright 2024 Dash0 Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-const crypto = require('node:crypto');
-const fs = require('node:fs/promises');
 const express = require('express');
 
 const port = parseInt(process.env.PORT || '1207');
@@ -22,18 +20,11 @@ const server = app.listen(port, () => {
 });
 
 if (process.env.TRIGGER_SELF_AND_EXIT) {
-  const testId = crypto.randomUUID();
-
   (async function () {
-    const testIdFile = process.env.TEST_ID_FILE || '/test-uuid/test.id';
-    try {
-      await fs.writeFile(testIdFile, testId);
-      console.log(`Test ID ${testId} has been written to file ${testIdFile}.`);
-    } catch (err) {
-      console.error(
-        `Unable to write test ID ${testId} to file ${testIdFile}, matching spans in the end-to-end test will not work.`,
-        err,
-      );
+    const testId = process.env.TEST_ID;
+    if (!testId) {
+      console.error('TEST_ID environment variable is not set, exiting');
+      process.exit(1);
     }
 
     for (let i = 0; i < 120; i++) {

test-resources/node.js/express/cronjob.yaml.template

@@ -22,16 +22,6 @@ spec:
                   value: "true"
                 - name: TRIGGER_SELF_AND_EXIT
                   value: "true"
-                - name: TEST_ID_FILE
-                  value: "/test-uuid/cronjob.test.id"
               ports:
                 - containerPort: 1205
               imagePullPolicy: Never
-              volumeMounts:
-                - name: test-uuid
-                  mountPath: /test-uuid
-          volumes:
-            - name: test-uuid
-              hostPath:
-                path: $PWD/test-resources/e2e-test-volumes/test-uuid
-                type: DirectoryOrCreate

test-resources/node.js/express/job.yaml.template

@@ -19,16 +19,6 @@ spec:
               value: "true"
             - name: TRIGGER_SELF_AND_EXIT
               value: "true"
-            - name: TEST_ID_FILE
-              value: "/test-uuid/job.test.id"
           ports:
             - containerPort: 1208
           imagePullPolicy: Never
-          volumeMounts:
-            - name: test-uuid
-              mountPath: /test-uuid
-      volumes:
-      - name: test-uuid
-        hostPath:
-          path: $PWD/test-resources/e2e-test-volumes/test-uuid
-          type: DirectoryOrCreate

test/e2e/application_under_test.go

@@ -9,12 +9,15 @@ import (
 	"os"
 	"os/exec"
 
+	"gopkg.in/yaml.v3"
+
 	. "github.com/onsi/ginkgo/v2" //nolint:golint,revive
 	. "github.com/onsi/gomega"
 )
 
 const (
 	applicationUnderTestNamespace = "e2e-application-under-test-namespace"
+	applicationPath               = "test-resources/node.js/express"
 )
 
 func rebuildNodeJsApplicationContainerImage() {
@@ -24,13 +27,14 @@ func rebuildNodeJsApplicationContainerImage() {
 			exec.Command(
 				"docker",
 				"build",
-				"test-resources/node.js/express",
+				applicationPath,
 				"-t",
 				"dash0-operator-nodejs-20-express-test-app",
 			))).To(Succeed())
 }
 
-func installNodeJsCronJob(namespace string) error {
+func installNodeJsCronJob(namespace string, testId string) error {
+	addTestIdToCronjobManifest(testId)
 	return installNodeJsApplication(
 		namespace,
 		"cronjob",
@@ -42,7 +46,7 @@ func uninstallNodeJsCronJob(namespace string) error {
 	return uninstallNodeJsApplication(namespace, "cronjob")
 }
 
-func installNodeJsDaemonSet(namespace string) error {
+func installNodeJsDaemonSet(namespace string, testId string) error {
 	return installNodeJsApplication(
 		namespace,
 		"daemonset",
@@ -60,7 +64,8 @@ func installNodeJsDaemonSet(namespace string) error {
 	)
 }
 
-func installNodeJsDaemonSetWithOptOutLabel(namespace string) error {
+//nolint:unparam
+func installNodeJsDaemonSetWithOptOutLabel(namespace string, testId string) error {
 	return installNodeJsApplication(
 		namespace,
 		"daemonset.opt-out",
@@ -82,7 +87,7 @@ func uninstallNodeJsDaemonSet(namespace string) error {
 	return uninstallNodeJsApplication(namespace, "daemonset")
 }
 
-func installNodeJsDeployment(namespace string) error {
+func installNodeJsDeployment(namespace string, testId string) error {
 	return installNodeJsApplication(
 		namespace,
 		"deployment",
@@ -104,7 +109,8 @@ func uninstallNodeJsDeployment(namespace string) error {
 	return uninstallNodeJsApplication(namespace, "deployment")
 }
 
-func installNodeJsJob(namespace string) error {
+func installNodeJsJob(namespace string, testId string) error {
+	addTestIdToJobManifest(testId)
 	return installNodeJsApplication(
 		namespace,
 		"job",
@@ -116,7 +122,8 @@ func uninstallNodeJsJob(namespace string) error {
 	return uninstallNodeJsApplication(namespace, "job")
 }
 
-func installNodeJsPod(namespace string) error {
+//nolint:unparam
+func installNodeJsPod(namespace string, testId string) error {
 	return installNodeJsApplication(
 		namespace,
 		"pod",
@@ -140,7 +147,8 @@ func uninstallNodeJsPod(namespace string) error {
 	return uninstallNodeJsApplication(namespace, "pod")
 }
 
-func installNodeJsReplicaSet(namespace string) error {
+//nolint:unparam
+func installNodeJsReplicaSet(namespace string, testId string) error {
 	return installNodeJsApplication(
 		namespace,
 		"replicaset",
@@ -164,7 +172,8 @@ func uninstallNodeJsReplicaSet(namespace string) error {
 	return uninstallNodeJsApplication(namespace, "replicaset")
 }
 
-func installNodeJsStatefulSet(namespace string) error {
+//nolint:unparam
+func installNodeJsStatefulSet(namespace string, testId string) error {
 	return installNodeJsApplication(
 		namespace,
 		"statefulset",
@@ -199,7 +208,7 @@ func removeAllTestApplications(namespace string) {
 
 func installNodeJsApplication(
 	namespace string,
-	templateName string,
+	workloadType string,
 	waitCommand *exec.Cmd,
 ) error {
 	err := runAndIgnoreOutput(exec.Command(
@@ -208,18 +217,18 @@ func installNodeJsApplication(
 		"--namespace",
 		namespace,
 		"-f",
-		fmt.Sprintf("test-resources/node.js/express/%s.yaml", templateName),
+		manifest(workloadType),
 	))
 	if err != nil {
 		return err
 	}
 	if waitCommand == nil {
 		return nil
 	}
-	return waitForApplicationToBecomeReady(templateName, waitCommand)
+	return waitForApplicationToBecomeReady(workloadType, waitCommand)
 }
 
-func uninstallNodeJsApplication(namespace string, kind string) error {
+func uninstallNodeJsApplication(namespace string, workloadType string) error {
 	return runAndIgnoreOutput(
 		exec.Command(
 			"kubectl",
@@ -228,7 +237,7 @@ func uninstallNodeJsApplication(namespace string, kind string) error {
 			namespace,
 			"--ignore-not-found",
 			"-f",
-			fmt.Sprintf("test-resources/node.js/express/%s.yaml", kind),
+			manifest(workloadType),
 		))
 }
 
@@ -259,7 +268,53 @@ func removeOptOutLabel(namespace string, workloadType string, workloadName strin
 		))
 }
 
-func deleteTestIdFiles() {
-	_ = os.Remove("test-resources/e2e-test-volumes/test-uuid/cronjob.test.id")
-	_ = os.Remove("test-resources/e2e-test-volumes/test-uuid/job.test.id")
+func addTestIdToCronjobManifest(testId string) {
+	filename := manifest("cronjob")
+	applicationManifestContentRaw, err := os.ReadFile(filename)
+	Expect(err).ToNot(HaveOccurred())
+	applicationManifestParsed := make(map[string]interface{})
+	Expect(yaml.Unmarshal(applicationManifestContentRaw, &applicationManifestParsed)).To(Succeed())
+	cronjobSpec := (applicationManifestParsed["spec"]).(map[string]interface{})
+	jobTemplate := (cronjobSpec["jobTemplate"]).(map[string]interface{})
+	jobTemplate["spec"] = addEnvVarToContainer(testId, jobTemplate)
+	cronjobSpec["jobTemplate"] = jobTemplate
+	applicationManifestParsed["spec"] = cronjobSpec
+	updatedApplicationManifestContentRaw, err := yaml.Marshal(&applicationManifestParsed)
+	Expect(err).ToNot(HaveOccurred())
+	Expect(os.WriteFile(filename, updatedApplicationManifestContentRaw, 0644)).To(Succeed())
+}
+
+func addTestIdToJobManifest(testId string) {
+	filename := manifest("job")
+	applicationManifestContentRaw, err := os.ReadFile(filename)
+	Expect(err).ToNot(HaveOccurred())
+	applicationManifestParsed := make(map[string]interface{})
+	Expect(yaml.Unmarshal(applicationManifestContentRaw, &applicationManifestParsed)).To(Succeed())
+	applicationManifestParsed["spec"] = addEnvVarToContainer(testId, applicationManifestParsed)
+	updatedApplicationManifestContentRaw, err := yaml.Marshal(&applicationManifestParsed)
+	Expect(err).ToNot(HaveOccurred())
+	Expect(os.WriteFile(filename, updatedApplicationManifestContentRaw, 0644)).To(Succeed())
+}
+
+func addEnvVarToContainer(testId string, jobTemplateOrManifest map[string]interface{}) map[string]interface{} {
+	jobSpec := (jobTemplateOrManifest["spec"]).(map[string]interface{})
+	template := (jobSpec["template"]).(map[string]interface{})
+	podSpec := (template["spec"]).(map[string]interface{})
+	containers := (podSpec["containers"]).([]interface{})
+	container := (containers[0]).(map[string]interface{})
+	env := (container["env"]).([]interface{})
+	newEnvVar := make(map[string]string)
+	newEnvVar["name"] = "TEST_ID"
+	newEnvVar["value"] = testId
+	env = append(env, newEnvVar)
+	container["env"] = env
+	containers[0] = container
+	podSpec["containers"] = containers
+	template["spec"] = podSpec
+	jobSpec["template"] = template
+	return jobSpec
+}
+
+func manifest(workloadType string) string {
+	return fmt.Sprintf("%s/%s.yaml", applicationPath, workloadType)
 }