uninstall: set "cni.uninstall" to true

There is a Helm variable, `cni.uninstall`, that tells the agent to clean
up its CNI configuration file and plugin binaries. This behavior was
disabled by default in PR cilium/cilium#24009.
However, when we *know* we're uninstalling Cilium, we should re-enable
the old behavior.

So, manually touch the key file in the configmap to enable uninstall.
Then, the pre-stop hook will be activated on shutdown and clean up as
usual.

Signed-off-by: Casey Callendrello <cdc@isovalent.com>

install/uninstall.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/cilium/workerpool"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 
@@ -26,6 +27,7 @@ type UninstallParameters struct {
 	HelmValuesSecretName string
 	RedactHelmCertKeys   bool
 	HelmChartDirectory   string
+	WorkerCount          int
 }
 
 type K8sUninstaller struct {
@@ -48,6 +50,8 @@ func (k *K8sUninstaller) Log(format string, a ...interface{}) {
 func (k *K8sUninstaller) Uninstall(ctx context.Context) error {
 	k.autodetect(ctx)
 
+	k.Log("🔥 Enabling CNI cleanup...")
+	k.enableCNIUninstall(ctx)
 	k.Log("🔥 Deleting agent DaemonSet...")
 	k.client.DeleteDaemonSet(ctx, k.params.Namespace, defaults.AgentDaemonSetName, metav1.DeleteOptions{})
 	// We need to wait for daemonset to be deleted before proceeding with further cleanups
@@ -133,3 +137,29 @@ func (k *K8sUninstaller) waitForPodsToBeDeleted(ctx context.Context) error {
 		}
 	}
 }
+
+func (k *K8sUninstaller) enableCNIUninstall(ctx context.Context) {
+	pods, err := k.client.ListPods(ctx, k.params.Namespace, metav1.ListOptions{LabelSelector: defaults.AgentPodSelector})
+	if err != nil {
+		k.Log("❌ Failed to enable cni cleanup: %v", err)
+		return
+	}
+	wp := workerpool.New(k.params.WorkerCount)
+
+	for i := range pods.Items {
+		pod := &(pods.Items[i]) // go iterator silliness; can't use range variable
+		wp.Submit(pod.Name, func(ctx context.Context) error {
+			_, err := k.client.ExecInPod(ctx, pod.Namespace, pod.Name, defaults.AgentContainerName,
+				[]string{
+					"/bin/sh",
+					"-c",
+					"echo -n true > /tmp/cilium/config-map/cni-uninstall || true",
+				})
+			if err != nil {
+				k.Log("❌ Failed to enable cni cleanup in pod %s: %v", pod.Name, err)
+			}
+			return nil
+		})
+	}
+	wp.Drain()
+}

internal/cli/cmd/install.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"runtime"
 	"strings"
 	"time"
 
@@ -187,6 +188,7 @@ func newCmdUninstall() *cobra.Command {
 	cmd.Flags().BoolVar(&params.RedactHelmCertKeys, "redact-helm-certificate-keys", true, "Do not print in the terminal any certificate keys generated by helm. (Certificates will always be stored unredacted in the secret defined by 'helm-values-secret-name')")
 	cmd.Flags().StringVar(&params.TestNamespace, "test-namespace", defaults.ConnectivityCheckNamespace, "Namespace to uninstall Cilium tests from")
 	cmd.Flags().BoolVar(&params.Wait, "wait", false, "Wait for uninstallation to have completed")
+	cmd.Flags().IntVar(&params.WorkerCount, "worker-count", runtime.NumCPU(), "Number of workers to use for parallel operations")
 
 	return cmd
 }