Support exec readiness probes for sidecar containers

Author: Florian Medja

Diff for: pkg/activator/handler/context.go

@@ -25,6 +25,7 @@ import (
 	"context"
 
 	"k8s.io/apimachinery/pkg/types"
+
 	v1 "knative.dev/serving/pkg/apis/serving/v1"
 )
 
@@ -50,7 +51,7 @@ func RevisionFrom(ctx context.Context) *v1.Revision {
 	return ctx.Value(revCtxKey{}).(*revCtx).revision
 }
 
-// RevIDFrom retrieves the the revisionID from the context.
+// RevIDFrom retrieves the revisionID from the context.
 func RevIDFrom(ctx context.Context) types.NamespacedName {
 	return ctx.Value(revCtxKey{}).(*revCtx).revID
 }

Diff for: pkg/reconciler/revision/resources/deploy_test.go

@@ -1521,6 +1521,45 @@ func TestMakePodSpec(t *testing.T) {
 					withEnvVar("SERVING_READINESS_PROBE", `[{"httpGet":{"path":"/","port":8080,"host":"127.0.0.1","scheme":"HTTP"}},{"httpGet":{"path":"/","port":8090,"host":"127.0.0.1","scheme":"HTTP"}}]`),
 				),
 			}),
+	}, {
+		name: "with multiple containers with exec probes",
+		rev: revision("bar", "foo",
+			withContainers([]corev1.Container{{
+				Name:           servingContainerName,
+				Image:          "busybox",
+				Ports:          buildContainerPorts(v1.DefaultUserPort),
+				ReadinessProbe: withExecReadinessProbe([]string{"bin/sh", "serving.sh"}),
+			}, {
+				Name:           sidecarContainerName,
+				Image:          "Ubuntu",
+				ReadinessProbe: withExecReadinessProbe([]string{"bin/sh", "sidecar.sh"}),
+			}}),
+			WithContainerStatuses([]v1.ContainerStatus{{
+				ImageDigest: "busybox@sha256:deadbeef",
+			}, {
+				ImageDigest: "ubuntu@sha256:deadbffe",
+			}}),
+		),
+		fc: apicfg.Features{
+			MultiContainerProbing: apicfg.Enabled,
+		},
+		want: podSpec(
+			[]corev1.Container{
+				servingContainer(func(container *corev1.Container) {
+					container.Image = "busybox@sha256:deadbeef"
+					container.ReadinessProbe = withExecReadinessProbe([]string{"bin/sh", "serving.sh"})
+				}),
+				sidecarContainer(sidecarContainerName,
+					func(container *corev1.Container) {
+						container.Image = "ubuntu@sha256:deadbffe"
+						container.ReadinessProbe = withExecReadinessProbe([]string{"bin/sh", "sidecar.sh"})
+					},
+				),
+				queueContainer(
+					withEnvVar("ENABLE_MULTI_CONTAINER_PROBES", "true"),
+					withEnvVar("SERVING_READINESS_PROBE", `[{"tcpSocket":{"port":8080,"host":"127.0.0.1"}}]`),
+				),
+			}),
 	}, {
 		name: "with default affinity type set",
 		rev: revision("bar", "foo",

Diff for: pkg/reconciler/revision/resources/queue.go

@@ -312,6 +312,9 @@ func makeQueueContainer(rev *v1.Revision, cfg *config.Config) (*corev1.Container
 					probePort = sc.ReadinessProbe.TCPSocket.Port.IntVal
 				case sc.ReadinessProbe.GRPC != nil && sc.ReadinessProbe.GRPC.Port > 0:
 					probePort = sc.ReadinessProbe.GRPC.Port
+				case sc.ReadinessProbe.Exec != nil:
+					// Skip the queue-proxy optimization for readiness probing when exec probe is defined on a sidecar container
+					continue
 				default:
 					return nil, fmt.Errorf("sidecar readiness probe does not define probe port on container: %s", sc.Name)
 				}

Diff for: pkg/reconciler/revision/resources/queue_test.go

@@ -441,7 +441,51 @@ func TestMakeQueueContainer(t *testing.T) {
 				"ENABLE_MULTI_CONTAINER_PROBES": "true",
 			})
 		}),
-	}}
+	}, {
+		name: "multi container probing enabled with exec probes on all containers",
+		rev: revision("bar", "foo", withContainers([]corev1.Container{
+			{
+				Name: servingContainerName,
+				ReadinessProbe: &corev1.Probe{
+					ProbeHandler: corev1.ProbeHandler{
+						Exec: &corev1.ExecAction{
+							Command: []string{"bin/sh", "serving.sh"},
+						},
+					},
+				},
+				Ports: []corev1.ContainerPort{{
+					ContainerPort: 1955,
+					Name:          string(netapi.ProtocolH2C),
+				}},
+			},
+			{
+				Name: sidecarContainerName,
+				ReadinessProbe: &corev1.Probe{
+					ProbeHandler: corev1.ProbeHandler{
+						Exec: &corev1.ExecAction{
+							Command: []string{"bin/sh", "sidecar.sh"},
+						},
+					},
+				},
+			},
+		})),
+		fc: apicfg.Features{
+			MultiContainerProbing: apicfg.Enabled,
+		},
+		dc: deployment.Config{
+			ProgressDeadline: 0 * time.Second,
+		},
+		want: queueContainer(func(c *corev1.Container) {
+			c.Ports = append(queueNonServingPorts, queueHTTP2Port, queueHTTPSPort)
+			c.ReadinessProbe.ProbeHandler.HTTPGet.Port.IntVal = queueHTTP2Port.ContainerPort
+			c.Env = env(map[string]string{
+				"ENABLE_MULTI_CONTAINER_PROBES": "true",
+				"USER_PORT":                     "1955",
+				"QUEUE_SERVING_PORT":            "8013",
+			})
+		}),
+	},
+	}
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {