Add TopologySpreadConstraints in PodTemplate

Add TopologySpreadConstraints in PodTemplate to enable spread Pods across cluster among topology domains.
tekton-robot · Aug 10, 2022 · 2323fba · 2323fba
1 parent bf8be59
commit 2323fba
Show file tree

Hide file tree

Showing 10 changed files with 151 additions and 2 deletions.
diff --git a/docs/podtemplates.md b/docs/podtemplates.md
@@ -110,6 +110,10 @@ Pod templates support fields listed in the table below.
 			<td><code>hostAliases</code></td>
 			<td>Adds entries to a Pod's `/etc/hosts` to provide Pod-level overrides of hostnames. For further info see [Kubernetes' docs for this field](https://kubernetes.io/docs/tasks/network/customize-hosts-file-for-pods/).</td>
 		</tr>
+        <tr>
+            <td><code>topologySpreadConstraints</code></td>
+            <td>Specify how Pods are spread across your cluster among topology domains.</td>
+        </tr>
 	</tbody>
 </table>
 

diff --git a/pkg/apis/pipeline/pod/template.go b/pkg/apis/pipeline/pod/template.go
@@ -113,6 +113,12 @@ type Template struct {
 	// HostNetwork specifies whether the pod may use the node network namespace
 	// +optional
 	HostNetwork bool `json:"hostNetwork,omitempty"`
+
+	// TopologySpreadConstraints controls how Pods are spread across your cluster among
+	// failure-domains such as regions, zones, nodes, and other user-defined topology domains.
+	// +optional
+	// +listType=atomic
+	TopologySpreadConstraints []corev1.TopologySpreadConstraint `json:"topologySpreadConstraints,omitempty"`
 }
 
 // Equals checks if this Template is identical to the given Template.

diff --git a/pkg/apis/pipeline/pod/zz_generated.deepcopy.go b/pkg/apis/pipeline/pod/zz_generated.deepcopy.go
diff --git a/pkg/apis/pipeline/v1/openapi_generated.go b/pkg/apis/pipeline/v1/openapi_generated.go
diff --git a/pkg/apis/pipeline/v1/swagger.json b/pkg/apis/pipeline/v1/swagger.json
@@ -118,6 +118,15 @@
           },
           "x-kubernetes-list-type": "atomic"
         },
+        "topologySpreadConstraints": {
+          "description": "TopologySpreadConstraints controls how Pods are spread across your cluster among failure-domains such as regions, zones, nodes, and other user-defined topology domains.",
+          "type": "array",
+          "items": {
+            "default": {},
+            "$ref": "#/definitions/v1.TopologySpreadConstraint"
+          },
+          "x-kubernetes-list-type": "atomic"
+        },
         "volumes": {
           "description": "List of volumes that can be mounted by containers belonging to the pod. More info: https://kubernetes.io/docs/concepts/storage/volumes",
           "type": "array",

diff --git a/pkg/apis/pipeline/v1beta1/openapi_generated.go b/pkg/apis/pipeline/v1beta1/openapi_generated.go
diff --git a/pkg/apis/pipeline/v1beta1/pod.go b/pkg/apis/pipeline/v1beta1/pod.go
@@ -79,6 +79,9 @@ func MergePodTemplateWithDefault(tpl, defaultTpl *PodTemplate) *PodTemplate {
 		if tpl.HostNetwork == false && defaultTpl.HostNetwork == true {
 			tpl.HostNetwork = true
 		}
+		if tpl.TopologySpreadConstraints == nil {
+			tpl.TopologySpreadConstraints = defaultTpl.TopologySpreadConstraints
+		}
 		return tpl
 	}
 }

diff --git a/pkg/apis/pipeline/v1beta1/swagger.json b/pkg/apis/pipeline/v1beta1/swagger.json
@@ -118,6 +118,15 @@
           },
           "x-kubernetes-list-type": "atomic"
         },
+        "topologySpreadConstraints": {
+          "description": "TopologySpreadConstraints controls how Pods are spread across your cluster among failure-domains such as regions, zones, nodes, and other user-defined topology domains.",
+          "type": "array",
+          "items": {
+            "default": {},
+            "$ref": "#/definitions/v1.TopologySpreadConstraint"
+          },
+          "x-kubernetes-list-type": "atomic"
+        },
         "volumes": {
           "description": "List of volumes that can be mounted by containers belonging to the pod. More info: https://kubernetes.io/docs/concepts/storage/volumes",
           "type": "array",

diff --git a/pkg/pod/pod.go b/pkg/pod/pod.go
@@ -347,6 +347,7 @@ func (b *Builder) Build(ctx context.Context, taskRun *v1beta1.TaskRun, taskSpec
 			PriorityClassName:            priorityClassName,
 			ImagePullSecrets:             podTemplate.ImagePullSecrets,
 			HostAliases:                  podTemplate.HostAliases,
+			TopologySpreadConstraints:    podTemplate.TopologySpreadConstraints,
 			ActiveDeadlineSeconds:        &activeDeadlineSeconds, // Set ActiveDeadlineSeconds to mark the pod as "terminating" (like a Job)
 		},
 	}

diff --git a/pkg/pod/pod_test.go b/pkg/pod/pod_test.go
@@ -1714,6 +1714,78 @@ _EOF_
 				}, runVolume(0)),
 				ActiveDeadlineSeconds: &defaultActiveDeadlineSeconds,
 			},
+		}, {
+			desc: "using TopologySpreadConstraints",
+			ts: v1beta1.TaskSpec{
+				Steps: []v1beta1.Step{
+					{
+						Name:    "use-topologySpreadConstraints",
+						Image:   "image",
+						Command: []string{"cmd"}, // avoid entrypoint lookup.
+					},
+				},
+			},
+			trs: v1beta1.TaskRunSpec{
+				PodTemplate: &pod.Template{
+					TopologySpreadConstraints: []corev1.TopologySpreadConstraint{
+						{
+							MaxSkew:           1,
+							TopologyKey:       "zone",
+							WhenUnsatisfiable: corev1.DoNotSchedule,
+							LabelSelector: &metav1.LabelSelector{
+								MatchLabels: map[string]string{
+									"foo": "bar",
+								},
+							},
+						},
+					},
+				},
+			},
+			want: &corev1.PodSpec{
+				RestartPolicy:  corev1.RestartPolicyNever,
+				InitContainers: []corev1.Container{entrypointInitContainer(images.EntrypointImage, []v1beta1.Step{{Name: "use-topologySpreadConstraints"}})},
+				TopologySpreadConstraints: []corev1.TopologySpreadConstraint{
+					{
+						MaxSkew:           1,
+						TopologyKey:       "zone",
+						WhenUnsatisfiable: corev1.DoNotSchedule,
+						LabelSelector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
+					},
+				},
+				Volumes: append(implicitVolumes, binVolume, runVolume(0), downwardVolume, corev1.Volume{
+					Name:         "tekton-creds-init-home-0",
+					VolumeSource: corev1.VolumeSource{EmptyDir: &corev1.EmptyDirVolumeSource{Medium: corev1.StorageMediumMemory}},
+				}),
+				Containers: []corev1.Container{{
+					Name:    "step-use-topologySpreadConstraints",
+					Image:   "image",
+					Command: []string{"/tekton/bin/entrypoint"},
+					Args: []string{
+						"-wait_file",
+						"/tekton/downward/ready",
+						"-wait_file_content",
+						"-post_file",
+						"/tekton/run/0/out",
+						"-termination_path",
+						"/tekton/termination",
+						"-step_metadata_dir",
+						"/tekton/run/0/status",
+						"-entrypoint",
+						"cmd",
+						"--",
+					},
+					VolumeMounts: append([]corev1.VolumeMount{binROMount, runMount(0, false), downwardMount, {
+						Name:      "tekton-creds-init-home-0",
+						MountPath: "/tekton/creds",
+					}}, implicitVolumeMounts...),
+					TerminationMessagePath: "/tekton/termination",
+				}},
+				ActiveDeadlineSeconds: &defaultActiveDeadlineSeconds,
+			},
 		}} {
 		t.Run(c.desc, func(t *testing.T) {
 			names.TestingSeed()