pod overrides now work as expected (#7)

corev1.PodSpec has attributes that are not omitempty (presuambly because
they are mandatory) which meant that the override spec would have nil on
those attributes, resulting in a broken podspec.

This PR also adds a symbolic e2e test because overrides was not tested
at all in a real cluster.

Author: bittrance

pkg/resources/pod.go

@@ -378,13 +378,25 @@ func applyPodOverrides(base, overrides corev1.PodSpec) corev1.PodSpec {
 		return base
 	}
 
+	// We diff overrides against an empty PodSpec to produce a patch containing only
+	// fields the user explicitly set (avoiding null fields from zero-value slices/maps
+	// that would otherwise wipe out base fields like Containers).
+	emptyJSON, err := json.Marshal(corev1.PodSpec{})
+	if err != nil {
+		return base
+	}
+	patch, err := strategicpatch.CreateTwoWayMergePatch(emptyJSON, overridesJSON, corev1.PodSpec{})
+	if err != nil {
+		return base
+	}
+
 	patchMeta, err := strategicpatch.NewPatchMetaFromStruct(&corev1.PodSpec{})
 	if err != nil {
 		return base
 	}
 
 	merged, err := strategicpatch.StrategicMergePatchUsingLookupPatchMeta(
-		baseJSON, overridesJSON, patchMeta)
+		baseJSON, patch, patchMeta)
 	if err != nil {
 		return base
 	}

pkg/resources/pod_test.go

@@ -310,6 +310,9 @@ func TestBuildPod_PodOverrides(t *testing.T) {
 	if pod.Spec.NodeSelector["gpu"] != "true" {
 		t.Errorf("expected nodeSelector gpu='true', got '%s'", pod.Spec.NodeSelector["gpu"])
 	}
+	if pod.Spec.Containers == nil {
+		t.Errorf("expected overrides not to touch container")
+	}
 }
 
 func TestBuildPod_CustomPort(t *testing.T) {

test/e2e/e2e_test.go

@@ -441,6 +441,49 @@ spec:
 			_, _ = utils.Run(cmd)
 		})
 
+		It("should add volumes from podOverrides", func() {
+			notebookName := "e2e-pod-overrides"
+
+			By("creating a MarimoNotebook with podOverrides volumes")
+			notebookYAML := fmt.Sprintf(`
+apiVersion: marimo.io/v1alpha1
+kind: MarimoNotebook
+metadata:
+  name: %s
+  namespace: %s
+spec:
+  source: "https://github.com/marimo-team/marimo.git"
+  podOverrides:
+    volumes:
+      - name: ssh-pubkey
+        secret:
+          secretName: ssh-pubkey
+          defaultMode: 0600
+`, notebookName, testNamespace)
+
+			yamlFile := filepath.Join("/tmp", notebookName+".yaml")
+			err := os.WriteFile(yamlFile, []byte(notebookYAML), 0644)
+			Expect(err).NotTo(HaveOccurred())
+
+			cmd := exec.Command("kubectl", "apply", "-f", yamlFile)
+			_, err = utils.Run(cmd)
+			Expect(err).NotTo(HaveOccurred(), "Failed to create MarimoNotebook")
+
+			By("verifying Pod has the overridden volume")
+			verifyVolumePresent := func(g Gomega) {
+				cmd := exec.Command("kubectl", "get", "pod", notebookName, "-n", testNamespace,
+					"-o", `jsonpath={.spec.volumes[?(@.name=="ssh-pubkey")].secret.secretName}`)
+				output, err := utils.Run(cmd)
+				g.Expect(err).NotTo(HaveOccurred())
+				g.Expect(output).To(Equal("ssh-pubkey"))
+			}
+			Eventually(verifyVolumePresent, 2*time.Minute, time.Second).Should(Succeed())
+
+			By("cleaning up")
+			cmd = exec.Command("kubectl", "delete", "marimo", notebookName, "-n", testNamespace)
+			_, _ = utils.Run(cmd)
+		})
+
 		It("should create sidecar containers with exposed ports", func() {
 			notebookName := "e2e-sidecar"