Introduction to GKE on Bare Metal
GKE on Bare Metal quickstart scope
With GKE on Bare Metal, you can define four types of clusters:
- admin - A cluster used to manage user clusters.
- user - A cluster used to run workloads.
- standalone - A single cluster that can administer itself, and that can also run workloads, but can't create or manage other user clusters.
- hybrid - A single cluster for both admin and workloads, that can also manage user clusters.
In this quickstart, you deploy a two-node hybrid cluster with GKE on Bare Metal. You learn how to create a cluster, and how to monitor the cluster creation process.
This quickstart assumes a basic understanding of Kubernetes
Preparing for GKE on Bare Metal
The install command of GKE on Bare Metal, called
bmctl, has been designed to
streamline the creation of clusters. The command can automatically set up
the necessary Google service accounts and APIs you need for GKE on Bare Metal,
and we'll use those automated services in this quickstart.
If you want to, you can also manually set up the necessary services and APIs
before you create clusters with
bmctl. We'll note the command
changes you need to make later in this document, but to set up the Google services
you need manually, see Enabling Google services and service accounts.
Before you can create a cluster using GKE on Bare Metal, ensure that you:
- Create a Google Cloud project where you have the Editor or Owner role.
- Download and install the
bmctlcommand-line tool as described below.
- Configure a Linux admin workstation for running
bmctl. Note: Do not use Cloud Shell as your admin workstation.
kubectlas described below.
- Install Docker version 19.03 or later. (For instructions on configuring Docker, see the page for configuring your Linux OS: Configuring CentOS, Configuring RHEL, or Configuring Ubuntu.)
rootaccess, set up SSH on both the admin workstation and the remote cluster node machines. Initially, you need
rootSSH password authentication enabled on the remote cluster node machines to share keys from the Admin workstation. Once the keys are in place, you can disable SSH password authentication.
- Generate a private/public key pair on the admin workstation (do not set
a passphrase for the keys). The keys are needed to use SSH for secure,
passwordless connections between the administration workstation and the
cluster node machines.
ssh-keygen -t rsa
You can also use
SUDOuser access to the cluster node machines to set up SSH, but for passwordless, non-root user connections you need to update the
cluster configYAML file with the appropriate credentials. For more information, see the
#Node access configurationsection in the sample cluster config file..
- Add the generated public key to the cluster node machines. By default,
the public keys are stored in the
ssh-copy-id -i ~/.ssh/identity_file root@cluster_node_ip
- Disable SSH password authentication on the cluster node machines and use
the following command on the admin workstation to verify the public key
authentication works between the admin workstation and the cluster node machines.
ssh -o IdentitiesOnly=yes -i identity_file root@cluster_node_ip
Installing gcloud utilities
kubectl tools are included in
the gcloud CLI.
- On your administration machine, install and initialize the gcloud CLI using the instructions
here. This process installs
- Update the gcloud CLI:
gcloud components update
Log in with your Google account so that you can manage services and service accounts:
gcloud auth login --update-adc
A new browser tab opens and you are prompted to choose an account.
Note that you can set up a Google Cloud default project at this point, and enable other services and Google APIs. before you create GKE on Bare Metal clusters. Setting a default project saves time when you enable services manually.
However, as shown in this quickstart, you can also specify a project, and set up the required Google services, directly with the
bmctlcommand when you create your clusters. When you do this,
bmctlalways uses the project ID you specify when issuing the command.
gcloud components install kubectl
The command-line tool for creating clusters in GKE on Bare Metal is
bmctl from a Cloud Storage bucket
- Create a new directory for
bmctlfrom the Cloud Storage bucket:
gsutil cp gs://anthos-baremetal-release/bmctl/1.6.2/linux-amd64/bmctl bmctl
chmod a+x bmctl
- Ensure that
bmctlis installed correctly by viewing the help information:
Creating your cluster nodes
Create two machines that will serve as nodes for your cluster:
- One machine functions as the control plane node.
- One machine functions as the worker node.
Note that your admin workstation needs to be able to
ssh to these nodes and
have access to the control plane VIP.
Creating a cluster
To create a cluster:
bmctlto create a config file.
- Edit the config file to customize it for your cluster and network.
bmctlto create the cluster from the config file.
Creating a config file
To create a config file, and enable service accounts and APIs automatically,
make sure you are in the
baremetal directory, and issue
bmctl command with the following flags:
./bmctl create config -c CLUSTER_NAME \ --enable-apis --create-service-accounts --project-id=PROJECT_ID
CLUSTER_NAME is the name of your cluster, and PROJECT_ID is a Google project where you have an Owner or Editor role.
This command creates a config file under the
Editing the config file
To edit the config file:
- Open the
bmctl-workspace/cluster1/cluster1.yamlconfig file in an editor.
- Edit the file for your specific node and network requirements. See the sample config file below. Note that in this quickstart, we've omitted the OpenID Connect (OIDC)
# gcrKeyPath: < to GCR service account key> gcrKeyPath: baremetal/gcr.json # sshPrivateKeyPath: < to SSH private key, used for node access> sshPrivateKeyPath: .ssh/id_rsa # gkeConnectAgentServiceAccountKeyPath: < to Connect agent service account key> gkeConnectAgentServiceAccountKeyPath: baremetal/connect-agent.json # gkeConnectRegisterServiceAccountKeyPath: < to Hub registration service account key> gkeConnectRegisterServiceAccountKeyPath: baremetal/connect-register.json # cloudOperationsServiceAccountKeyPath: < to Cloud Operations service account key> cloudOperationsServiceAccountKeyPath: baremetal/cloud-ops.json --- apiVersion: v1 kind: Namespace metadata: name: cluster-cluster1 --- apiVersion: baremetal.cluster.gke.io/v1 kind: Cluster metadata: name: cluster1 namespace: cluster-cluster1 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: hybrid # Anthos cluster version. anthosBareMetalVersion: 1.6.2 # GKE connect configuration gkeConnect: projectID: 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: CONTROL_PLANE_NODE_IP # 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 VIPs 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: - 172.26.232.0/24 # 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 LB 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 VIPs: 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. vips: # ControlPlaneVIP specifies the VIP to connect to the Kubernetes API server. # This address must not be in the address pools below. controlPlaneVIP: CONTROL_PLANE_VIP # 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: INGRESS_VIP # 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 (188.8.131.52/24) # # or range form (184.108.40.206-220.127.116.11). # - LOAD_BALANCER_ADDRESS_POOL- # A load balancer nodepool 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: LOAD_BALANCER_NODE_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: 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 --- # Node pools for worker nodes apiVersion: baremetal.cluster.gke.io/v1 kind: NodePool metadata: name: node-pool-1 namespace: cluster-cluster1 spec: clusterName: cluster1 nodes: - address: WORKER_NODE_IP
Running preflight checks and creating the cluster
bmctl command runs preflight checks
on your cluster config file before it creates a cluster. If they're successful,
the cluster is created.
To run preflight checks and create the cluster:
- Ensure that you are in the
- Use the following command to create the cluster:
./bmctl create cluster -c CLUSTER_NAMEFor example:
./bmctl create cluster -c cluster1
bmctl command monitors the preflight checks and cluster creation,
and then displays output to the screen and writes verbose information
bmctl logs, as well as the preflight check and node installation logs,
are in the directory:
bmctl preflight checks the proposed cluster installation for the
- The Linux distribution and version are supported.
- SELinux is not in "enforcing" mode.
- For Ubuntu, AppArmor and UFW are not active.
- For CentOS/RHEL, firewalld is not active.
- Google Container Registry is reachable.
- The VIPs are available.
- The cluster machines have connectivity to each other.
- Load balancer machines are on the same L2 subnet.
It can take several minutes to finish the cluster creation.
Getting information about your cluster
After the cluster is created successfully, the
shows you information about the new cluster. During cluster creation, the
bmctl command writes a kubeconfig file for the cluster that you
kubectl. The kubeconfig file is written to
kubectl --kubeconfig bmctl-workspace/cluster1/cluster1-kubeconfig get nodes
This command returns:
NAME STATUS ROLES AGE VERSION
node-01 Ready master 16h v1.17.8-gke.16
node-02 Ready <none> 16h v1.17.8-gke.16
If your cluster creation fails preflight checks, then check the preflight check logs for
errors, and correct them in the cluster config file. The preflight check logs are located
The preflight check logs for each machine in the cluster are in the
CLUSTER_NAME directory, and are organized by IP address.
Ignoring pre-flight check errors
If your cluster creation fails after pre-flight checks, you can try to re-install the
cluster by using the
--force flag in the
--force flag installs over an existing cluster, but ignores
the results from any preflight check failure due to already allocated server ports.
- Ensure that you are in the
- Use the following command with the
--forceflag to re-create the cluster:
./bmctl create cluster -c CLUSTER_NAME --forceFor example:
./bmctl create cluster -c cluster1 --force
Creating a Deployment and a Service
Here's a manifest for a Deployment:
- name: hello
Save the manifest as
my-deployment.yaml, and create the Deployment:
kubectl --kubeconfig bmctl-workspace/cluster1/cluster1-kubeconfig create -f my-deployment.yaml
View the Deployment:
kubectl --kubeconfig bmctl-workspace/cluster1/cluster1-kubeconfig get deployments
The output shows that the Deployment has three running Pods:
NAME READY UP-TO-DATE AVAILABLE AGE
my-deployment 3/3 3 3 16s
Here's a manifest for a Service of type LoadBalancer:
- port: 80
Save the manifest as
my-service.yaml, and create the Service:
kubectl --kubeconfig bmctl-workspace/cluster1/cluster1-kubeconfig create -f my-service.yaml
View the Service:
kubectl --kubeconfig bmctl-workspace/cluster1/cluster1-kubeconfig get service my-service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S
my-service LoadBalancer 172.26.232.2 172.16.1.21 80:30060/TCP
Notice that GKE on Bare Metal has given the service an external IP address.
Use the external IP address to call the Service:
The output is a hello world message:
Creating a high availability control plane
This quickstart creates a simple two-node hybrid cluster. If you want to create a high availability control plane, create a cluster that has three control plane nodes.
For example, edit the config file shown above to add to additional nodes to the control
# Control Plane node pools. Typically, this is either a single machine
# or 3 machines if using a high availability deployment.
- address: <Machine 1 IP>
- address: <Machine 2 IP>
- address: <Machine 3 IP>
Running the load balancer in its own node pool
This quickstart creates a simple two-node hybrid cluster. The load balancer runs on the same node that runs the control plane.
If you want the load balancer to run in its own node pool, edit the
values of the
loadBalancer section of your config file:
loadBalancer: nodePoolSpec: clusterName: "cluster1" nodes: - address: <LB Machine 1 IP> - address: <LB Machine 2 IP>