Version 1.8. This version is supported as outlined in the Anthos version support policy, offering the latest patches and updates for security vulnerabilities, exposures, and issues impacting Anthos clusters on VMware (GKE on-prem). Refer to the release notes for more details. This is not the most recent version.

Available versions:   1.11    1.10    1.9    Earlier versions

Known issues

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This document describes known issues for version 1.8 of Anthos clusters on VMware (GKE on-prem).

/var/log/audit/ filling up disk space

Category

OS

Identified Versions

1.8.0+, 1.9.0+, 1.10.0+, 1.11.0+, 1.12.0+, 1.13.0+

Symptoms

/var/log/audit/ is filled with audit logs. You can check the disk usage by running sudo du -h -d 1 /var/log/audit.

Cause

Since Anthos v1.8, the Ubuntu image is hardened with CIS Level2 Benchmark. And one of the compliance rules, 4.1.2.2 Ensure audit logs are not automatically deleted, ensures the auditd setting max_log_file_action = keep_logs. This results in all the audit rules kept on the disk.

Workaround

Admin workstation

For the admin workstation, you can manually change the auditd settings to rotate the logs automatically, and then restart the auditd service:

sed -i 's/max_log_file_action = keep_logs/max_log_file_action = rotate/g' /etc/audit/auditd.conf
sed -i 's/num_logs = .*/num_logs = 250/g' /etc/audit/auditd.conf
systemctl restart auditd

The above setting would make auditd automatically rotate its logs once it has generated more than 250 files (each with 8M size).

Cluster nodes

For cluster nodes, apply the following DaemonSet to your cluster to prevent potential issues:

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: change-auditd-log-action
  namespace: kube-system
spec:
  selector:
    matchLabels:
      app: change-auditd-log-action
  template:
    metadata:
      labels:
        app: change-auditd-log-action
    spec:
      hostIPC: true
      hostPID: true
      containers:
      - name: update-audit-rule
        image: ubuntu
        command: ["chroot", "/host", "bash", "-c"]
        args:
        - |
          while true; do
            if $(grep -q "max_log_file_action = keep_logs" /etc/audit/auditd.conf); then
              echo "updating auditd max_log_file_action to rotate with a max of 250 files"
              sed -i 's/max_log_file_action = keep_logs/max_log_file_action = rotate/g' /etc/audit/auditd.conf
              sed -i 's/num_logs = .*/num_logs = 250/g' /etc/audit/auditd.conf
              echo "restarting auditd"
              systemctl restart auditd
            else
              echo "auditd setting is expected, skip update"
            fi
            sleep 600
          done
        volumeMounts:
        - name: host
          mountPath: /host
        securityContext:
          privileged: true
      volumes:
      - name: host
        hostPath:
          path: /

Note that making this auditd config change would violate CIS Level2 rule 4.1.2.2 Ensure audit logs are not automatically deleted.

User cluster upgrade/update fails due to 'failed to register user cluster'

Category

Upgrade, Update

Identified Versions

1.7.0+, 1.8.0+

Symptoms

Run gkectl diagnose cluster when a previous gkectl command timed out in the following cases.

  1. Upgrading user clusters with GKE connect enabled to 1.8 versions.
  2. Running gkectl update cluster on 1.8 user clusters with GKE connect enabled.
  3. Running gkectl update cluster to enable GKE connect on 1.8 user clusters.
$ gkectl diagnose cluster --kubeconfig kubeconfig --cluster-name foo-cluster
…
    Unhealthy Resources:
      OnPremUserCluster foo-cluster: not ready: ready condition is not true: ClusterCreateOrUpdate: failed to register user cluster "foo-cluster": failed to register cluster: ...
...

Note that the functionality of GKE connect should not be affected. In other words, if GKE connect was functional before the command, it should remain functional.

Cause

The Connect Agent version 20210514-00-00 used in 1.8 versions is out of support.

Workaround

Please contact Google support to mitigate the issue.

systemd-timesyncd not running after reboot on Ubuntu Node

Category

OS

Identified Versions

1.7.1-1.7.5, 1.8.0-1.8.4, 1.9.0+

Symptoms

systemctl status systemd-timesyncd should show that the service is dead:

● systemd-timesyncd.service - Network Time Synchronization
Loaded: loaded (/lib/systemd/system/systemd-timesyncd.service; enabled; vendor preset: enabled)
Active: inactive (dead)

This could cause time out of sync issues.

Cause

chrony was incorrectly installed on Ubuntu OS image, and there's conflict between chrony and systemd-timesyncd, where systemd-timesyncd would become inactive and chrony become active everytime Ubuntu VM got rebooted. However, systemd-timesyncd should be the default ntp client for the VM.

Workaround

Option 1: Manually run restart systemd-timesyncd every time when VM got rebooted.

Option 2: Deploy the following Daemonset so that systemd-timesyncd will always be restarted if it's dead.

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: ensure-systemd-timesyncd
spec:
  selector:
    matchLabels:
      name: ensure-systemd-timesyncd
  template:
    metadata:
      labels:
        name: ensure-systemd-timesyncd
    spec:
      hostIPC: true
      hostPID: true
      containers:
      - name: ensure-systemd-timesyncd
        # Use your preferred image.
        image: ubuntu
        command:
        - /bin/bash
        - -c
        - |
          while true; do
            echo $(date -u)
            echo "Checking systemd-timesyncd status..."
            chroot /host systemctl status systemd-timesyncd
            if (( $? != 0 )) ; then
              echo "Restarting systemd-timesyncd..."
              chroot /host systemctl start systemd-timesyncd
            else
              echo "systemd-timesyncd is running."
            fi;
            sleep 60
          done
        volumeMounts:
        - name: host
          mountPath: /host
        resources:
          requests:
            memory: "10Mi"
            cpu: "10m"
        securityContext:
          privileged: true
      volumes:
      - name: host
        hostPath:
          path: /
````

## ClientConfig custom resource

`gkectl update` reverts any manual changes that you have made to the ClientConfig
custom resource. We strongly recommend that you back up the ClientConfig
resource after every manual change.

## gkectl check-config</code> validation fails: can't find F5 BIG-IP partitions

<dl>
<dt>Symptoms</dt>
<dd><p>Validation fails because F5 BIG-IP partitions can't be found, even though they exist.</p></dd>
<dt>Potential causes</dt>
<dd><p>An issue with the F5 BIG-IP API can cause validation to fail.</p></dd>
<dt>Resolution</dt>
<dd><p>Try running <code>gkectl check-config</code> again.</p></dd>
</dl>

## Disruption for workloads with PodDisruptionBudgets {:#workloads_pdbs_disruption}

Upgrading clusters can cause disruption or downtime for workloads that use
[PodDisruptionBudgets](https://kubernetes.io/docs/concepts/workloads/pods/disruptions/){:.external} 
(PDBs).

## Nodes fail to complete their upgrade process

If you have `PodDisruptionBudget` objects configured that are unable to
allow any additional disruptions, node upgrades might fail to upgrade to the
control plane version after repeated attempts. To prevent this failure, we
recommend that you scale up the `Deployment` or `HorizontalPodAutoscaler` to
allow the node to drain while still respecting the `PodDisruptionBudget`
configuration.

To see all `PodDisruptionBudget` objects that do not allow any disruptions:

kubectl get poddisruptionbudget --all-namespaces -o jsonpath='{range .items[?(@.status.disruptionsAllowed==0)]}{.metadata.name}/{.metadata.namespace}{"\n"}{end}' ```

User cluster installation failed because of cert-manager/ca-injector's leader election issue in Anthos 1.8.2 and 1.8.3

You might see an installation failure due to cert-manager-cainjector in crashloop, when the apiserver/etcd is slow. The following command,

  kubectl logs --kubeconfig USER_CLUSTER_KUBECONFIG -n kube-system deployments/cert-manager-cainjector
might produce something like the following logs:

I0923 16:19:27.911174       1 leaderelection.go:278] failed to renew lease kube-system/cert-manager-cainjector-leader-election: timed out waiting for the condition
E0923 16:19:27.911110       1 leaderelection.go:321] error retrieving resource lock kube-system/cert-manager-cainjector-leader-election-core: Get "https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/cert-manager-cainjector-leader-election-core": context deadline exceeded
I0923 16:19:27.911593       1 leaderelection.go:278] failed to renew lease kube-system/cert-manager-cainjector-leader-election-core: timed out waiting for the condition
E0923 16:19:27.911629       1 start.go:163] cert-manager/ca-injector "msg"="error running core-only manager" "error"="leader election lost"

Run the following commands to mitigate the problem.

First, scale down the monitoring-operator so it will not revert the changes to the cert-manager-cainjector Deployment.

kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG -n USER_CLUSTER_NAME scale deployment monitoring-operator --replicas=0

Second, patch the cert-manager-cainjector Deployment to disable leader election, which is safe because we only have one replica running. It is not required for a single replica.

# Ensure that we run only 1 cainjector replica, even during rolling updates.
kubectl patch --kubeconfig USER_CLUSTER_KUBECONFIG -n kube-system deployment cert-manager-cainjector --type=strategic --patch '
spec:
  strategy:
    rollingUpdate:
      maxSurge: 0
'
# Add a command line flag for cainjector: `--leader-elect=false`
kubectl patch --kubeconfig USER_CLUSTER_KUBECONFIG -n kube-system deployment cert-manager-cainjector --type=json --patch '[
    {
        "op": "add",
        "path": "/spec/template/spec/containers/0/args/-",
        "value": "--leader-elect=false"
    }
]'

Keep monitoring-operator replicas at 0 as a mitigation until the installation is finished. Otherwise it will revert the change.

After the installation is finished and the cluster is up and running, turn on the monitoring-operator for day-2 operations:

kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG -n USER_CLUSTER_NAME scale deployment monitoring-operator --replicas=1

Note that after upgrading to 1.8.4 and above (or 1.9.1 and above, if upgrading to 1.9), these steps will no longer be necessary since Anthos will disable leader-election for cainjector. Until then, if you face this issue during each upgrade, it will be necessary to perform the same mitigation steps again.

Renewal of certificates might be required before an admin cluster upgrade

Before you begin the admin cluster upgrade process, you should make sure that your admin cluster certificates are currently valid, and renew these certificates if they are not.

Admin cluster certificate renewal process

  1. Make sure that OpenSSL is installed on the admin workstation before you begin.

  2. Set the KUBECONFIG variable:

    KUBECONFIG=ABSOLUTE_PATH_ADMIN_CLUSTER_KUBECONFIG
    

    Replace ABSOLUTE_PATH_ADMIN_CLUSTER_KUBECONFIG with the absolute path to the admin cluster kubeconfig file.

  3. Get the IP address and SSH keys for the admin master node:

    kubectl --kubeconfig "${KUBECONFIG}" get secrets -n kube-system sshkeys \
    -o jsonpath='{.data.vsphere_tmp}' | base64 -d > \
    ~/.ssh/admin-cluster.key && chmod 600 ~/.ssh/admin-cluster.key
    
    export MASTER_NODE_IP=$(kubectl --kubeconfig "${KUBECONFIG}" get nodes -o \
    jsonpath='{.items[*].status.addresses[?(@.type=="ExternalIP")].address}' \
    --selector='node-role.kubernetes.io/master')
    
  4. Check if the certificates are expired:

    ssh -i ~/.ssh/admin-cluster.key ubuntu@"${MASTER_NODE_IP}" \
    "sudo kubeadm alpha certs check-expiration"
    

    If the certificates are expired, you must renew them before upgrading the admin cluster.

  5. Back up old certificates:

    This is an optional, but recommended, step.

    # ssh into admin master
    ssh -i ~/.ssh/admin-cluster.key ubuntu@"${MASTER_NODE_IP}"
    
    # on admin master
    sudo tar -czvf backup.tar.gz /etc/kubernetes
    logout
    
    # on worker node
    sudo scp -i ~/.ssh/admin-cluster.key \
    ubuntu@"${MASTER_NODE_IP}":/home/ubuntu/backup.tar.gz .
    
  6. Renew the certificates with kubeadm:

     # ssh into admin master
     ssh -i ~/.ssh/admin-cluster.key ubuntu@"${MASTER_NODE_IP}"
     # on admin master
     sudo kubeadm alpha certs renew all
     

  7. Restart the admin master node:

      # on admin master
      cd /etc/kubernetes
      sudo mkdir tempdir
      sudo mv manifests/*.yaml tempdir/
      sleep 5
      echo "remove pods"
      # ensure kubelet detect those change remove those pods
      # wait until the result of this command is empty
      sudo docker ps | grep kube-apiserver
    
      # ensure kubelet start those pods again
      echo "start pods again"
      sudo mv tempdir/*.yaml manifests/
      sleep 30
      # ensure kubelet start those pods again
      # should show some results
      sudo docker ps | grep -e kube-apiserver -e kube-controller-manager -e kube-scheduler -e etcd
    
      # clean up
      sudo rm -rf tempdir
    
      logout
     
  8. Because the admin cluster kubeconfig file also expires if the admin certificates expire, you should back up this file before expiration.

    • Back up the admin cluster kubeconfig file:

      ssh -i ~/.ssh/admin-cluster.key ubuntu@"${MASTER_NODE_IP}" 
      "sudo cat /etc/kubernetes/admin.conf" > new_admin.conf vi "${KUBECONFIG}"

    • Replace client-certificate-data and client-key-data in kubeconfig with client-certificate-data and client-key-data in the new_admin.conf file that you created.

  9. Renew the certificates of admin cluster worker nodes

    Check node certificates expiration date

        kubectl get nodes -o wide
        # find the oldest node, fill NODE_IP with the internal ip of that node
        ssh -i ~/.ssh/admin-cluster.key ubuntu@"${NODE_IP}"
        openssl x509 -enddate -noout -in /var/lib/kubelet/pki/kubelet-client-current.pem
        logout
       

    If the certificate is about to expire, renew node certificates by manual node repair.

  10. You must validate the renewed certificates, and validate the certificate of kube-apiserver.

    • Check certificates expiration:

      ssh -i ~/.ssh/admin-cluster.key ubuntu@"${MASTER_NODE_IP}" 
      "sudo kubeadm alpha certs check-expiration"

    • Check certificate of kube-apiserver:

      # Get the IP address of kube-apiserver
      cat $KUBECONFIG | grep server
      # Get the current kube-apiserver certificate
      openssl s_client -showcerts -connect : 
      | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p'
      > current-kube-apiserver.crt # check expiration date of this cert openssl x509 -in current-kube-apiserver.crt -noout -enddate

/etc/cron.daily/aide script uses up all space in /run, causing a crashloop in Pods

Starting from Anthos clusters on VMware 1.7.2, the Ubuntu OS images are hardened with CIS L1 Server Benchmark. . As a result, the cron script /etc/cron.daily/aide has been installed so that an aide check is scheduled to ensure the CIS L1 Server rule "1.4.2 Ensure filesystem integrity is regularly checked".

The script uses /run/aide as a temporary directory to save its cron logs, and over time it could use up all the space in /run. See /etc/cron.daily/aide script uses all space in /run for a workaround.

If you see one or more Pods crashlooping on a node, run df -h /run on the node. If the command output shows 100% space usage, then you are likely experiencing this issue.

This issue is fixed in version 1.8.1. For the 1.7.2 and 1.8.0 versions, you can resolve this issue manually with either of the following two workarounds:

  1. Periodically remove the log files at /run/aide/cron.daily.old* (recommended).
  2. Follow the steps mentioned in /etc/cron.daily/aide script uses all space in /run. (Note: this workaround could potentially affect the node compliance state).

Upgrading Seesaw load balancer with version 1.8.0

If you use the gkectl upgrade loadbalancer to attempt to update some parameters of the Seesaw load balancer in version 1.8.0, this will not work in either DHCP or IPAM mode. If your setup includes this configuration, do not upgrade to version 1.8.0, but instead to version 1.8.1 or later.

Cannot log in to admin workstation due to password expiry issue

You might experience this issue if you are using one of the following versions of Anthos clusters on VMware.

  • 1.7.2-gke.2
  • 1.7.3-gke.2
  • 1.8.0-gke.21
  • 1.8.0-gke.24
  • 1.8.0-gke.25
  • 1.8.1-gke.7
  • 1.8.2-gke.8

You might get the following error when you attempt to SSH into your Anthos VMs, including the admin workstation, cluster nodes, and Seesaw nodes:

WARNING: Your password has expired.

This error occurs because the ubuntu user password on the VMs has expired. You must manually reset the user password's expiration time to a large value before logging into the VMs.

Prevention of password expiry error

If you are running the affected versions listed above, and the user password hasn't expired yet, you should extend the expiration time before seeing the SSH error.

Run the following command on each Anthos VM:

sudo chage -M 99999 ubuntu

Mitigation of password expiry error

If the user password has already expired and you can't log in to the VMs to extend the expiration time, perform the following mitigation steps for each component.

Admin workstation

Use a temporary VM to perform the following steps. You can create an admin workstation using the 1.7.1-gke.4 version to use as the temporary VM.

  1. Ensure the temporary VM and the admin workstation are in a power off state.

  2. Attach the boot disk of the admin workstation to the temporary VM. The boot disk is the one with the label "Hard disk 1".

  3. Mount the boot disk inside the VM by running these commands. Substitute your own boot disk identifier for dev/sdc1.

    sudo mkdir -p /mnt/boot-disk
    sudo mount /dev/sdc1 /mnt/boot-disk
    
  4. Set the ubuntu user expiration date to a large value such as 99999 days.

    sudo chroot /mnt/boot-disk chage -M 99999 ubuntu
    
  5. Shut down the temporary VM.

  6. Power on the admin workstation. You should now be able to SSH as usual.

  7. As cleanup, delete the temporary VM.

Admin cluster control plane VM

Follow the instructions to recreate the admin cluster control plane VM.

Admin cluster addon VMs

Run the following command from the admin workstation to recreate the VM:

  kubectl --kubeconfig=ADMIN_CLUSTER_KUBECONFIG patch machinedeployment gke-admin-node --type=json -p="[{'op': 'add', 'path': '/spec/template/spec/metadata/annotations', 'value': {"kubectl.kubernetes.io/restartedAt": "version1"}}]"
  

After you run this command, wait for the admin cluster addon VMs to finish recreation and to be ready before you continue with the next steps.

User cluster control plane VMs

Run the following command from the admin workstation to recreate the VMs:

usermaster=`kubectl --kubeconfig=ADMIN_CLUSTER_KUBECONFIG get machinedeployments -l set=user-master -o name` && kubectl --kubeconfig=ADMIN_CLUSTER_KUBECONFIG patch $usermaster --type=json -p="[{'op': 'add', 'path': '/spec/template/spec/metadata/annotations', 'value': {"kubectl.kubernetes.io/restartedAt": "version1"}}]"

After you run this command, wait for the user cluster control plane VMs to finish recreation and to be ready before you continue with the next steps.

User cluster worker VMs

Run the following command from the admin workstation to recreate the VMs.

for md in `kubectl --kubeconfig=USER_CLUSTER_KUBECONFIG get machinedeployments -l set=node -o name`; do kubectl patch --kubeconfig=USER_CLUSTER_KUBECONFIG $md --type=json -p="[{'op': 'add', 'path': '/spec/template/spec/metadata/annotations', 'value': {"kubectl.kubernetes.io/restartedAt": "version1"}}]"; done

Seesaw VMs

Run the following commands from the admin workstation to recreate the Seesaw VMs. There will be some downtime. If HA is enabled for the load balancer, the maximum down time is two seconds.

gkectl upgrade loadbalancer --kubeconfig ADMIN_CLUSTER_KUBECONFIG --config ADMIN_CLUSTER_CONFIG --admin-cluster --no-diff
gkectl upgrade loadbalancer --kubeconfig ADMIN_CLUSTER_KUBECONFIG --config USER_CLUSTER_CONFIG --no-diff

Restarting or upgrading vCenter for versions lower than 7.0U2

If the vCenter, for versions lower than 7.0U2, is restarted, after an upgrade or otherwise, the network name in VM Information from vCenter is incorrect, and results in the machine being in an Unavailable state. This eventually leads to the nodes being auto-repaired to create new ones.

Related govmomi bug: https://github.com/vmware/govmomi/issues/2552

This workaround is provided by VMware support:

1. The issue is fixed in vCenter versions 7.0U2 and above.

2. For lower versions:
Right-click the host, and then select Connection > Disconnect. Next, reconnect, which forces an update of the 
VM's portgroup.

gkectl create-config admin and gkectl create-config cluster panic

In versions 1.8.0-1.8.3, the gkectl create-config admin/cluster command panics with the message panic: invalid version: "latest".

As a workaround, use gkectl create-config admin/cluster --gke-on-prem-version=DESIRED_CLUSTER_VERSION. Replace DESIRED_CLUSTER_VERSION with the desired version, such as 1.8.2-gke.8.

Creating/upgrading admin cluster timeout

This issue affects 1.8.0-1.8.3.

Your admin cluster creation or admin cluster upgrade might time out with the following error:

Error getting kubeconfig: error running remote command 'sudo cat /etc/kubernetes/admin.conf': error: Process exited with status 1, stderr: 'cat: /etc/kubernetes/admin.conf: No such file or directory

In addition, the log at nodes/ADMIN_MASTER_NODE/files/var/log/startup.log in the external cluster snapshot ends with this message:

[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'

This error happens when the network is slow between the admin control-plane VM and the container registry. Make sure to inspect your network or proxy setup to reduce the latency and increase the bandwidth.

SSH connection closed by remote host

For Anthos clusters on VMware version 1.7.2 and above, the Ubuntu OS images are hardened with CIS L1 Server Benchmark. To meet the CIS rule "5.2.16 Ensure SSH Idle Timeout Interval is configured", /etc/ssh/sshd_config has the following settings:

ClientAliveInterval 300
ClientAliveCountMax 0

The purpose of these settings is to terminate a client session after 5 minutes of idle time. However, the ClientAliveCountMax 0 value causes unexpected behavior. When you use the ssh session on the admin workstation, or a cluster node, the SSH connection might be disconnected even your ssh client is not idle, such as when running a time-consuming command, and your command could get terminated with the following message:

Connection to [IP] closed by remote host.
Connection to [IP] closed.

As a workaround, you can either:

  • Use nohup to prevent your command being terminated on SSH disconnection,

    nohup gkectl upgrade admin --config admin-cluster.yaml --kubeconfig kubeconfig
    
  • Update the sshd_config to use a non-zero ClientAliveCountMax value. The CIS rule recommends to use a value less than 3.

    sudo sed -i 's/ClientAliveCountMax 0/ClientAliveCountMax 1/g' /etc/ssh/sshd_config
    sudo systemctl restart sshd
    

    Make sure you reconnect your ssh session.

Conflict with cert-manager when upgrading to version 1.8.2 or above

If you have your own cert-manager installation with Anthos clusters on VMware, you might experience a failure when you attempt to upgrade to versions 1.8.2 or above. This is a result of a conflict between your version of cert-manager, which is likely installed in the cert-manager namespace, and the monitoring-operator version.

If you try to install another copy of cert-manager after upgrading to Anthos clusters on VMware version 1.8.2 or above, the installation might fail due to a conflict with the existing one managed by monitoring-operator.

The metrics-ca cluster issuer, which control-plane and observability components rely on for creation and rotation of cert secrets, requires a metrics-ca cert secret to be stored in the cluster resource namespace. This namespace is kube-system for the monitoring-operator installation, and likely to be cert-manager for your installation.

If you have experienced an installation failure, follow these steps to upgrade successfully to version 1.8.2 or later:

Avoid conflicts during upgrade

  1. Uninstall your version of cert-manager. If you defined your own resources, you may want to backup them.

  2. Perform the upgrade.

  3. Follow the following instructions to restore your own cert-manager.

Restore your own cert-manager in user clusters

  • Scale the monitoring-operator deployment to 0.

    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG -n USER_CLUSTER_NAME scale deployment monitoring-operator --replicas=0

  • Scale the cert-manager deployments managed by monitoring-operator to 0.

    kubectl --kubeconfig USER_CLUSTER_KUBECONFIG -n kube-system scale deployment cert-manager --replicas=0
    kubectl --kubeconfig USER_CLUSTER_KUBECONFIG -n kube-system scale deployment cert-manager-cainjector --replicas=0
    kubectl --kubeconfig USER_CLUSTER_KUBECONFIG -n kube-system scale deployment cert-manager-webhook --replicas=0
      

  • Reinstall the customer's cert-manager. Restore your customized resources if you have.

  • Copy the metrics-ca cert-manager.io/v1 Certificate and the metrics-pki.cluster.local Issuer resources from kube-system to the cluster resource namespace of your installed cert-manager. Your installed cert-manager namespace is cert-manager if using the upstream default cert-manager installation, but that depends on your installation.

    relevant_fields='
    {
    apiVersion: .apiVersion,
    kind: .kind,
    metadata: {
    name: .metadata.name,
    namespace: "YOUR_INSTALLED_CERT_MANAGER_NAMESPACE"
    },
    spec: .spec
    }
    '
    f1=$(mktemp)
    f2=$(mktemp)
    kubectl --kubeconfig USER_CLUSTER_KUBECONFIG get issuer -n kube-system metrics-pki.cluster.local -o json | jq "${relevant_fields}" > $f1
    kubectl --kubeconfig USER_CLUSTER_KUBECONFIG get certificate -n kube-system metrics-ca -o json | jq "${relevant_fields}" > $f2
    kubectl apply --kubeconfig USER_CLUSTER_KUBECONFIG -f $f1
    kubectl apply --kubeconfig USER_CLUSTER_KUBECONFIG -f $f2
     

Restore your own cert-manager in admin clusters

In general, you shouldn't need to re-install cert-manager in admin clusters because admin clusters only run Anthos clusters on VMware control plane workloads. In the rare cases that you also need to install your own cert-manager in admin clusters, please follow the following instructions to avoid conflicts. Please note, if you are an Apigee customer and you only need cert-manager for Apigee, you do not need to run the admin cluster commands.

  • Scale the monitoring-operator deployment to 0.

    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG -n kube-system scale deployment monitoring-operator --replicas=0

  • Scale the cert-manager deployments managed by monitoring-operator to 0.

    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG -n kube-system scale deployment cert-manager --replicas=0
    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG -n kube-system scale deployment cert-manager-cainjector --replicas=0
    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG -n kube-system scale deployment cert-manager-webhook --replicas=0
      

  • Reinstall the customer's cert-manager. Restore your customized resources if you have.

  • Copy the metrics-ca cert-manager.io/v1 Certificate and the metrics-pki.cluster.local Issuer resources from kube-system to the cluster resource namespace of your installed cert-manager. Your installed cert-manager namespace is cert-manager if using the upstream default cert-manager installation, but that depends on your installation.

    relevant_fields='
    {
    apiVersion: .apiVersion,
    kind: .kind,
    metadata: {
    name: .metadata.name,
    namespace: "YOUR_INSTALLED_CERT_MANAGER_NAMESPACE"
    },
    spec: .spec
    }
    '
    f3=$(mktemp)
    f4=$(mktemp)
    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG get issuer -n kube-system metrics-pki.cluster.local -o json | jq "${relevant_fields}" > $f3
    kubectl --kubeconfig ADMIN_CLUSTER_KUBECONFIG get certificate -n kube-system metrics-ca -o json | jq "${relevant_fields}" > $f4
    kubectl apply --kubeconfig ADMIN_CLUSTER_KUBECONFIG -f $f3
    kubectl apply --kubeconfig ADMIN_CLUSTER_KUBECONFIG -f $f4
     

False positives in docker, containerd, and runc vulnerability scanning

The docker, containerd, and runc in the Ubuntu OS images shipped with Anthos clusters on VMware are pinned to special versions using Ubuntu PPA. This ensures that any container runtime changes will be qualified by Anthos clusters on VMware before each release.

However, the special versions are unknown to the Ubuntu CVE Tracker, which is used as the vulnerability feeds by various CVE scanning tools. Therefore, you will see false positives in docker, containerd, and runc vulnerability scanning results.

For example, you might see the following false positives from your CVE scanning results. These CVEs are already fixed in the latest patch versions of Anthos clusters on VMware.

Refer to the release notes for any CVE fixes.

Canonical is aware of this issue, and the fix is tracked at https://github.com/canonical/sec-cvescan/issues/73.

/etc/cron.daily/aide CPU and memory spike issue

Starting from Anthos clusters on VMware version 1.7.2, the Ubuntu OS images are hardened with CIS L1 Server Benchmark.

As a result, the cron script /etc/cron.daily/aide has been installed so that an aide check is scheduled so as to ensure that the CIS L1 Server rule "1.4.2 Ensure filesystem integrity is regularly checked" is followed.

The cron job runs daily at 6:00 AM UTC. Depending on the number of files on the filesystem, you may experience CPU and memory usage spikes around that time that are caused by this aide process.

If the spikes are affecting your workload, you can disable the daily cron job:

`sudo chmod -x /etc/cron.daily/aide`.

Cisco ACI doesn't work with Direct Server Return (DSR)

Seesaw runs in DSR mode, and by default it doesn't work in Cisco ACI because of data-plane IP learning. A possible workaround is to disable IP learning by adding the Seesaw IP address as a L4-L7 Virtual IP in the Cisco Application Policy Infrastructure Controller (APIC).

You can configure the L4-L7 Virtual IP option by going to Tenant > Application Profiles > Application EPGs or uSeg EPGs. Failure to disable IP learning will result in IP endpoint flapping between different locations in the Cisco API fabric.

A service account bearer token that is too long can break Seesaw load balancer logs

If your logging-monitoring service account bearer token is larger than 512 KB, it can break the Seesaw load balancer logs. To fix this issue, upgrade to version 1.9 or later.

Connectivity issues between Pods due to anetd daemons in software deadlock

Clusters with enableDataplaneV2 set to true can experience connectivity issues between Pods due to anetd daemons (running as a Daemonset) entering a software deadlock. While in this state, anetd daemons will see stale nodes (previously deleted nodes) as peers and miss newly added nodes as new peers.

If you have experienced this issue, complete the following steps to restart the anetd daemons to refresh the peer nodes, and connectivity should be restored.

  1. Find all anetd daemons in the cluster:

    kubectl --kubeconfig=USER_CLUSTER_KUBECONFIG -n kube-system get pods -o wide | grep anetd
    
  2. Check whether anetd daemons currently see stale peers:

    kubectl --kubeconfig=USER_CLUSTER_KUBECONFIG -n kube-system exec -it ANETD_XYZ -- cilium-health status
    

    Replace ANETD_XYZ with the name of an anetd Pod.

  3. Restart all affected Pods:

    kubectl --kubeconfig=USER_CLUSTER_KUBECONFIG -n kube-system delete pod ANETD_XYZ
    

gkectl diagnose checking certificates failure

If your work station does not have access to user cluster worker nodes, it will get the following failures when running gkectl diagnose, it is safe to ignore them.

Checking user cluster certificates...FAILURE
    Reason: 3 user cluster certificates error(s).
    Unhealthy Resources:
    Node kubelet CA and certificate on node xxx: failed to verify kubelet certificate on node xxx: dial tcp xxx.xxx.xxx.xxx:10250: connect: connection timed out
    Node kubelet CA and certificate on node xxx: failed to verify kubelet certificate on node xxx: dial tcp xxx.xxx.xxx.xxx:10250: connect: connection timed out
    Node kubelet CA and certificate on node xxx: failed to verify kubelet certificate on node xxx: dial tcp xxx.xxx.xxx.xxx:10250: connect: connection timed out