Version 1.7. This version is no longer supported. For information about how to upgrade to version 1.8, see Upgrading Anthos on bare metal in the 1.8 documentation. For more information about supported and unsupported versions, see the Version history page in the latest documentation.

Creating user clusters in a multi-cluster setup

In Google Distributed Cloud, user clusters run your workloads, and in a multi-cluster architecture, user clusters are created and managed by an admin cluster.

Once you've created an admin cluster, calling the bmctl create config command creates a yaml file you can edit to define your user cluster. To apply the configuration and create the user cluster, you can use the bmctl create cluster command in Google Distributed Cloud 1.7.0 and later versions. Preflight checks are applicable to the user clusters created with bmctl create cluster command.

Keeping workloads off the admin cluster protects sensitive administrative data, like SSH keys stored in the admin cluster, from those who don't need access to that information. Additionally, keeping user clusters separate from each other provides good general security for your workloads.

Prerequisites

Latest bmctl is downloaded (gs://anthos-baremetal-release/bmctl/1.7.7/linux-amd64/bmctl) from Cloud Storage.
Working admin cluster with access to the cluster API server (the controlPlaneVIP).
Admin cluster nodes have network connectivity to all nodes on the target user cluster.
Workstation running bmctl has network connectivity to all nodes in the target user clusters.
SSH key used to create user cluster available to root or SUDO user on all nodes in the user cluster.
For 1.7.0 and later versions, connect-register service account is configured on the admin cluster for use with Connect.

Create a user cluster config file

The config file for creating a user cluster is almost exactly the same as the one used for creating an admin cluster. The only difference is that you remove the local credentials configuration section to make the config a valid collection of Kubernetes resources. The configuration section is at the top of the file under the bmctl configuration variables section.

By default, user clusters inherit their credentials from the admin cluster that manages them. You can selectively override some or all of these credentials. See the sample user cluster config file for more details.

Create a user cluster config file with the bmctl create config command:

bmctl create config -c USER_CLUSTER_NAME

For example, issue the following to create a config file for a user cluster called user1:

bmctl create config -c user1

The file is written to bmctl-workspace/user1/user1.yaml. The generic path to the file is bmctl-workspace/CLUSTER NAME/CLUSTER_NAME.yaml

Edit the config file with the following changes:

Remove the local credentials file paths from the config:

....
  gcrKeyPath: (path to GCR service account key)
  sshPrivateKeyPath: (path to SSH private key, used for node access)
  gkeConnectAgentServiceAccountKeyPath: (path to Connect agent service account key)
  gkeConnectRegisterServiceAccountKeyPath: (path to Hub registration service account key)
  cloudOperationsServiceAccountKeyPath: (path to Cloud Operations service account key)
....

Change the config to specify a cluster type of user instead of admin:

....
spec:
  # Cluster type. This can be:
  #   1) admin:  to create an admin cluster. This can later be used to create
  #   user clusters.
  #   2) user:   to create a user cluster. Requires an existing admin cluster.
  #   3) hybrid: to create a hybrid cluster that runs admin cluster
  #   components and user workloads.
  #   4) standalone: to create a cluster that manages itself, runs user
  #   workloads, but does not manage other clusters.
  type: user
....

Ensure the admin and user cluster specifications for the load balancer VIPs and address pools are complementary, and do not overlap existing clusters. A sample pair of admin and user cluster configurations, specifying load balancing and address pools, is shown below:

....
# Sample admin cluster config for load balancer and address pools
  loadBalancer:
    vips:
      controlPlaneVIP: 10.200.0.49
      ingressVIP: 10.200.0.50
    addressPools:
    - name: pool1
      addresses:
      - 10.200.0.50-10.200.0.70
....
....
# Sample user cluster config for load balancer and address pools
loadBalancer:
    vips:
      controlPlaneVIP: 10.200.0.71
      ingressVIP: 10.200.0.72
    addressPools:
    - name: pool1
      addresses:
      - 10.200.0.72-10.200.0.90
....

The rest of the user cluster config files are the same as the admin cluster config.

Specify the pod density of cluster nodes and the container runtime:

....
# NodeConfig specifies the configuration that applies to all nodes in the cluster.
nodeConfig:
  # podDensity specifies the pod density configuration.
  podDensity:
    # maxPodsPerNode specifies at most how many pods can be run on a single node.
    maxPodsPerNode: 110
  # containerRuntime specifies which container runtime to use for scheduling containers on nodes.
  # containerd and docker are supported.
  containerRuntime: containerd
....

For user clusters, allowable values for maxPodsPerNode are 32-250. The default value if unspecified is 110. Once the cluster is created, this value cannot be updated.

Pod density is also limited by your cluster's available IP resources. For details, see Pod networking.

Create the user cluster

Issue the bmctl command to apply the user cluster config and create the cluster:

bmctl create cluster -c USER_CLUSTER_NAME --kubeconfig ADMIN_KUBECONFIG

Replace the following:

USER_CLUSTER_NAME: the cluster name created in the previous section.
ADMIN_KUBECONFIG: the path to the admin cluster kubeconfig file.

For example, for a user cluster named user1, and an admin cluster kubeconfig file with the path kubeconfig bmctl-workspace/admin/admin-kubeconfig, the command would be:

bmctl create cluster -c user1 --kubeconfig bmctl-workspace/admin/admin-kubeconfig

Sample complete user cluster config

The following is a sample user cluster config file created by the bmctl command. Note that in this sample config, placeholder cluster names, VIPs and addresses are used. They may not work for your network. Credentials will be inherited from the admin cluster by default. If you want to override the credentials, you need to provide the corresponding key paths in the configuration variables section.

# Sample user cluster config:

# ---
# To override default credentials
# gcrKeyPath: #/bmctl/bmctl-workspace/.sa-keys/my-gcp-project-anthos-baremetal-gcr.json
# sshPrivateKeyPath: /bmctl/bmctl-workspace/.ssh/id_rsa
# gkeConnectAgentServiceAccountKeyPath: #/bmctl/bmctl-workspace/.sa-keys/my-gcp-project-anthos-baremetal-connect.json
# gkeConnectRegisterServiceAccountKeyPath: #/bmctl/bmctl-workspace/.sa-keys/my-gcp-project-anthos-baremetal-register.json
# cloudOperationsServiceAccountKeyPath: #/bmctl/bmctl-workspace/.sa-keys/my-gcp-project-anthos-baremetal-cloud-ops.json
---
apiVersion: v1
kind: Namespace
metadata:
  name: cluster-user1
---
apiVersion: baremetal.cluster.gke.io/v1
kind: Cluster
metadata:
  name: user1
  namespace: cluster-user1
spec:
  # Cluster type. This can be:
  #   1) admin:  to create an admin cluster. This can later be used to create user clusters.
  #   2) user:   to create a user cluster. Requires an existing admin cluster.
  #   3) hybrid: to create a hybrid cluster that runs admin cluster components and user workloads.
  #   4) standalone: to create a cluster that manages itself, runs user workloads, 
  #   but does not manage other clusters.
  type: user
  # Anthos cluster version.
  anthosBareMetalVersion: 1.7.7
  # GKE connect configuration
  gkeConnect:
    projectID: GOOGLE_PROJECT_ID
  # Control plane configuration
  controlPlane:
    nodePoolSpec:
      nodes:
      # Control plane node pools. Typically, this is either a single machine
      # or 3 machines if using a high availability deployment.
      - address: 10.200.0.4
  # Cluster networking configuration
  clusterNetwork:
    # Pods specify the IP ranges from which pod networks are allocated.
    pods:
      cidrBlocks:
      - 192.168.0.0/16
    # Services specify the network ranges from which service virtual IPs are allocated.
    # This can be any RFC 1918 range that does not conflict with any other IP range
    # in the cluster and node pool resources.
    services:
      cidrBlocks:
      - 10.96.0.0/20
  # Load balancer configuration
  loadBalancer:
    # Load balancer mode can be either 'bundled' or 'manual'.
    # In 'bundled' mode a load balancer will be installed on load balancer nodes during cluster creation.
    # In 'manual' mode the cluster relies on a manually-configured external load balancer.
    mode: bundled
    # Load balancer port configuration
    ports:
      # Specifies the port the load balancer serves the Kubernetes control plane on.
      # In 'manual' mode the external load balancer must be listening on this port.
      controlPlaneLBPort: 443
    # There are two load balancer virtual IP (VIP) addresses: one for the control plane
    # and one for the L7 Ingress service. The VIPs must be in the same subnet as the load balancer nodes.
    # These IP addresses do not correspond to physical network interfaces.
    vips:
      # ControlPlaneVIP specifies the VIP to connect to the Kubernetes API server.
      # This address must not be in the address pools below.
      controlPlaneVIP: 10.200.0.71
      # IngressVIP specifies the VIP shared by all services for ingress traffic.
      # Allowed only in non-admin clusters.
      # This address must be in the address pools below.
      ingressVIP: 10.200.0.72
    # AddressPools is a list of non-overlapping IP ranges for the data plane load balancer.
    # All addresses must be in the same subnet as the load balancer nodes.
    # Address pool configuration is only valid for 'bundled' LB mode in non-admin clusters.
    addressPools:
    - name: pool1
      addresses:
      # Each address must be either in the CIDR form (1.2.3.0/24)
      # or range form (1.2.3.1-1.2.3.5).
      - 10.200.0.72-10.200.0.90
    # A load balancer node pool can be configured to specify nodes used for load balancing.
    # These nodes are part of the Kubernetes cluster and run regular workloads as well as load balancers.
    # If the node pool config is absent then the control plane nodes are used.
    # Node pool configuration is only valid for 'bundled' LB mode.
    # nodePoolSpec:
    #  nodes:
    #  - address: <Machine 1 IP>
  # Proxy configuration
  # proxy:
  #   url: http://[username:password@]domain
  #   # A list of IPs, hostnames or domains that should not be proxied.
  #   noProxy:
  #   - 127.0.0.1
  #   - localhost
  # Logging and Monitoring
  clusterOperations:
    # Cloud project for logs and metrics.
    projectID: $GOOGLE_PROJECT_ID
    # Cloud location for logs and metrics.
    location: us-central1
    # Whether collection of application logs/metrics should be enabled (in addition to
    # collection of system logs/metrics which correspond to system components such as
    # Kubernetes control plane or cluster management agents).
    # enableApplication: false
  # Storage configuration
  storage:
    # lvpNodeMounts specifies the config for local PersistentVolumes backed by mounted disks.
    # These disks need to be formatted and mounted by the user, which can be done before or after
    # cluster creation.
    lvpNodeMounts:
      # path specifies the host machine path where mounted disks will be discovered and a local PV
      # will be created for each mount.
      path: /mnt/localpv-disk
      # storageClassName specifies the StorageClass that PVs will be created with. The StorageClass
      # is created during cluster creation.
      storageClassName: local-disks
    # lvpShare specifies the config for local PersistentVolumes backed by subdirectories in a shared filesystem.
    # These subdirectories are automatically created during cluster creation.
    lvpShare:
      # path specifies the host machine path where subdirectories will be created on each host. A local PV
      # will be created for each subdirectory.
      path: /mnt/localpv-share
      # storageClassName specifies the StorageClass that PVs will be created with. The StorageClass
      # is created during cluster creation.
      storageClassName: local-shared
      # numPVUnderSharedPath specifies the number of subdirectories to create under path.
      numPVUnderSharedPath: 5
  # NodeConfig specifies the configuration that applies to all nodes in the cluster.
  nodeConfig:
    # podDensity specifies the pod density configuration.
    podDensity:
      # maxPodsPerNode specifies at most how many pods can be run on a single node.
      maxPodsPerNode: 250
    # containerRuntime specifies which container runtime to use for scheduling containers on nodes.
    # containerd and docker are supported.
    containerRuntime: containerd
  # KubeVirt configuration, uncomment this section if you want to install kubevirt to the cluster
  # kubevirt:
  #   # if useEmulation is enabled, hardware accelerator (i.e relies on cpu feature like vmx or svm)
  #   # will not be attempted. QEMU will be used for software emulation.
  #   # useEmulation must be specified for KubeVirt installation
  #   useEmulation: false
  # Authentication; uncomment this section if you wish to enable authentication to the cluster with OpenID Connect.
  # authentication:
  #   oidc:
  #     # issuerURL specifies the URL of your OpenID provider, such as "https://accounts.google.com". The Kubernetes API
  #     # server uses this URL to discover public keys for verifying tokens. Must use HTTPS.
  #     issuerURL: <URL for OIDC Provider; required>
  #     # clientID specifies the ID for the client application that makes authentication requests to the OpenID
  #     # provider.
  #     clientID: <ID for OIDC client application; required>
  #     # clientSecret specifies the secret for the client application.
  #     clientSecret: <Secret for OIDC client application; optional>
  #     # kubectlRedirectURL specifies the redirect URL (required) for the gcloud CLI, such as
  #     # "http://localhost:[PORT]/callback".
  #     kubectlRedirectURL: &lt;Redirect URL for the gcloud CLI; optional, default is "http://kubectl.redirect.invalid"&gt;
  #     # username specifies the JWT claim to use as the username. The default is "sub", which is expected to be a
  #     # unique identifier of the end user.
  #     username: <JWT claim to use as the username; optional, default is "sub">
  #     # usernamePrefix specifies the prefix prepended to username claims to prevent clashes with existing names.
  #     usernamePrefix: <Prefix prepended to username claims; optional>
  #     # group specifies the JWT claim that the provider will use to return your security groups.
  #     group: <JWT claim to use as the group name; optional>
  #     # groupPrefix specifies the prefix prepended to group claims to prevent clashes with existing names.
  #     groupPrefix: <Prefix prepended to group claims; optional>
  #     # scopes specifies additional scopes to send to the OpenID provider as a comma-delimited list.
  #     scopes: <Additional scopes to send to OIDC provider as a comma-separated list; optional>
  #     # extraParams specifies additional key-value parameters to send to the OpenID provider as a comma-delimited
  #     # list.
  #     extraParams: <Additional key-value parameters to send to OIDC provider as a comma-separated list; optional>
  #     # proxy specifies the proxy server to use for the cluster to connect to your OIDC provider, if applicable.
  #     # Example: https://user:password@10.10.10.10:8888. If left blank, this defaults to no proxy.
  #     proxy: <Proxy server to use for the cluster to connect to your OIDC provider; optional, default is no proxy>
  #     # deployCloudConsoleProxy specifies whether to deploy a reverse proxy in the cluster to allow Google Cloud
  #     # Console access to the on-premises OIDC provider for authenticating users. If your identity provider is not
  #     # reachable over the public internet, and you wish to authenticate using Google Cloud console, then this field
  #     # must be set to true. If left blank, this field defaults to false.
  #     deployCloudConsoleProxy: <Whether to deploy a reverse proxy for Google Cloud console authentication; optional>
  #     # certificateAuthorityData specifies a Base64 PEM-encoded certificate authority certificate of your identity
  #     # provider. It's not needed if your identity provider's certificate was issued by a well-known public CA.
  #     # However, if deployCloudConsoleProxy is true, then this value must be provided, even for a well-known public
  #     # CA.
  #     certificateAuthorityData: <Base64 PEM-encoded certificate authority certificate of your OIDC provider; optional>
  # Node access configuration; uncomment this section if you wish to use a non-root user
  # with passwordless sudo capability for machine login.
  # nodeAccess:
  #   loginUser: <login user name>
---
# Node pools for worker nodes
apiVersion: baremetal.cluster.gke.io/v1
kind: NodePool
metadata:
  name: node-pool-1
  namespace: cluster-user1
spec:
  clusterName: user1
  nodes:
  - address: 10.200.0.5