Google Kubernetes Engine

Follow these steps to create a Google Kubernetes Engine (GKE) cluster for your Agones install.

Before you begin

Take the following steps to enable the Kubernetes Engine API:

  1. Visit the Kubernetes Engine page in the Google Cloud Platform Console.
  2. Create or select a project.
  3. Wait for the API and related services to be enabled. This can take several minutes.
  4. Enable billing for your project.
  • If you are not an existing GCP user, you may be able to enroll for a $300 US Free Trial credit.

Choosing a shell

To complete this quickstart, we can use either Google Cloud Shell or a local shell.

Google Cloud Shell is a shell environment for managing resources hosted on Google Cloud Platform (GCP). Cloud Shell comes preinstalled with the gcloud and kubectl command-line tools. gcloud provides the primary command-line interface for GCP, and kubectl provides the command-line interface for running commands against Kubernetes clusters.

If you prefer using your local shell, you must install the gcloud and kubectl command-line tools in your environment.

Cloud shell

To launch Cloud Shell, perform the following steps:

  1. Go to Google Cloud Platform Console
  2. From the top-right corner of the console, click the Activate Google Cloud Shell button: cloud shell
  3. A Cloud Shell session opens inside a frame at the bottom of the console. Use this shell to run gcloud and kubectl commands.

Local shell

To install gcloud and kubectl, perform the following steps:

  1. Install the Google Cloud SDK, which includes the gcloud command-line tool.
  2. Initialize some default configuration by running the following command.
    • When asked Do you want to configure a default Compute Region and Zone? (Y/n)?, enter Y and choose a zone in your geographical region of choice.
    gcloud init
    
  3. Install the kubectl command-line tool by running the following command:
    gcloud components install kubectl
    

Choosing a Regional or Zonal Cluster

You will need to pick a geographical region or zone where you want to deploy your cluster, and whether to create a regional or zonal cluster. We recommend using a Regional cluster, as the zonal GKE control plane can go down temporarily to adjust for cluster resizing, automatic upgrades and repairs.

After choosing a cluster type, choose a region or zone. The region you chose is COMPUTE_REGION below. (Note that if you chose a zone, replace --region=[COMPUTE_REGION] with --zone=[COMPUTE_ZONE] in commands below.)

Choosing a Release Channel and Optional Version

We recommend using the regular release channel, which offers a balance between stability and freshness. If you’d like to read more, see our guide on Release Channels. The release channel you chose is RELEASE_CHANNEL below.

(Optional) During cluster creation, to set a specific available version in the release channel, use the --cluster-version=[VERSION] flag, e.g. --cluster-version=1.28. Be sure to choose a version supported by Agones. (If you rely on release channels, the latest Agones release should be supported by the default versions of all channels.)

Choosing a GKE cluster mode

A cluster consists of at least one control plane machine and multiple worker machines called nodes. In Google Kubernetes Engine, nodes are Compute Engine virtual machine instances that run the Kubernetes processes necessary to make them part of the cluster.

Agones supports both GKE Standard mode and GKE Autopilot mode. Agones GameServer and Fleet manifests that work on Standard are compatible on Autopilot with some constraints, described in the following section. We recommend running GKE Autopilot clusters, if you meet the constraints.

You can’t convert existing Standard clusters to Autopilot; create new Autopilot clusters instead.

Agones on GKE Autopilot

Autopilot is GKE’s fully-managed mode. GKE configures, maintains, scales, and upgrades nodes for you, which can reduce your maintenance and operating overhead. You only pay for the resources requested by your running Pods, and you don’t pay for unused node capacity or Kubernetes system workloads.

This section describes the Agones-specific considerations in Autopilot clusters. For a general comparison between Autopilot and Standard, refer to Choose a GKE mode of operation.

Autopilot nodes are, by default, optimized for most workloads. If some of your workloads have broad compute requirements such as Arm architecture or a minimum CPU platform, you can also choose a compute class that meets that requirement. However, if you have specialized hardware needs that require fine-grained control over machine configuration, consider using GKE Standard.

Agones on Autopilot has pre-configured opinionated constraints. Evaluate whether these constraints impact your workloads:

  • Operating system: No Windows containers.
  • Resource requests: Autopilot has pre-determined minimum Pod resource requests. If your game servers require less than those minimums, use GKE Standard.
  • Scheduling strategy: Packed is supported, which is the Agones default. Distributed is not supported.
  • Host port policy: Dynamic is supported, which is the Agones default. Static and Passthrough are not supported.
  • Port range: default is supported, which is the Agones default. Additional port ranges are not supported.
  • Seccomp profile: Agones sets the seccomp profile to Unconfined to avoid unexpected container creation delays that might occur because Autopilot enables the RuntimeDefault seccomp profile.
  • Pod disruption policy: eviction.safe: Never is supported, which is the Agones default. eviction.safe: Always is supported. eviction.safe: OnUpgrade is not supported. If your game sessions exceed one hour, refer to Considerations for long sessions.

Choosing a GCP network

By default, gcloud and the Cloud Console use the VPC named default for all new resources. If you plan to create a dual-stack IPv4/IPv6 cluster cluster, special considerations need to be made. Dual-stack clusters require a dual-stack subnet, which are only supported in custom mode VPC networks. For a new dual-stack cluster, you can either:

  • create a new custom mode VPC,

  • or if you wish to continue using the default network, you must switch it to custom mode. After switching a network to custom mode, you will need to manually manage subnets within the default VPC.

Once you have a custom mode VPC, you will need to choose whether to use an existing subnet or create a new one - read VPC-native guide on creating a dual-stack cluster, but don’t create the cluster just yet - we’ll create the cluster later in this guide. To use the network and/or subnetwork you just created, you’ll need to add --network and --subnetwork, and for GKE Standard, possibly --stack-type and --ipv6-access-type, depending on whether you created the subnet simultaneously with the cluster.

Creating the firewall

We need a firewall to allow UDP traffic to nodes tagged as game-server via ports 7000-8000. These firewall rules apply to cluster nodes you will create in the next section.

gcloud compute firewall-rules create gke-agones-game-server-firewall \
  --allow udp:7000-8000 \
  --target-tags game-server \
  --description "Firewall to allow game server udp traffic"

Creating the cluster

Create a GKE cluster in which you’ll install Agones. You can use GKE Standard mode or GKE Autopilot mode. You can read more about choosing a cluster mode above.

Create an Autopilot mode cluster for Agones

  1. Choose a Release Channel (Autopilot clusters must be on a Release Channel).

  2. Create the cluster:

    gcloud container clusters create-auto [CLUSTER_NAME] \
      --region=[COMPUTE_REGION] \
      --release-channel=[RELEASE_CHANNEL] \
      --autoprovisioning-network-tags=game-server
    

Replace the following:

  • [CLUSTER_NAME]: The name of your cluster.
  • [COMPUTE_REGION]: the GCP region to create the cluster in.
  • [RELEASE_CHANNEL]: one of rapid, regular, or stable, chosen above. The default is regular.

Flag explanations:

  • --region: The compute region you chose above.
  • --release-channel: The release channel you chose above.
  • --autoprovisioning-network-tags: Defines the tags that will be attached to new nodes in the cluster. This is to grant access through ports via the firewall created above.

Create a Standard mode cluster for Agones

Create the cluster:

gcloud container clusters create [CLUSTER_NAME] \
  --region=[COMPUTE_REGION] \
  --release-channel=[RELEASE_CHANNEL] \
  --tags=game-server \
  --scopes=gke-default \
  --num-nodes=4 \
  --enable-image-streaming \
  --machine-type=e2-standard-4

Replace the following:

  • [CLUSTER_NAME]: The name of the cluster you want to create
  • [COMPUTE_REGION]: The GCP region to create the cluster in, chosen above
  • [RELEASE_CHANNEL]: The GKE release channel, chosen above

Flag explanations:

  • --region: The compute region you chose above.
  • --release-channel: The release channel you chose above.
  • --tags: Defines the tags that will be attached to new nodes in the cluster. This is to grant access through ports via the firewall created above.
  • --scopes: Defines the Oauth scopes required by the nodes.
  • --num-nodes: The number of nodes to be created in each of the cluster’s zones. Default: 4. Depending on the needs of your game, this parameter should be adjusted.
  • --enable-image-streaming: Use Image streaming to pull container images, which leads to significant improvements in initialization times. Limitations apply to enable this feature.
  • --machine-type: The type of machine to use for nodes. Default: e2-standard-4. Depending on the needs of your game, you may wish to have smaller or larger machines.

(Optional) Creating a dedicated node pool

Create a dedicated node pool for the Agones resources to be installed in. If you skip this step, the Agones controllers will share the default node pool with your game servers, which is fine for experimentation but not recommended for a production deployment.

gcloud container node-pools create agones-system \
  --cluster=[CLUSTER_NAME] \
  --region=[COMPUTE_REGION] \
  --node-taints agones.dev/agones-system=true:NoExecute \
  --node-labels agones.dev/agones-system=true \
  --num-nodes=1 \
  --machine-type=e2-standard-4

Replace the following:

  • [CLUSTER_NAME]: The name of the cluster you created
  • [COMPUTE_REGION]: The GCP region to create the cluster in, chosen above

Flag explanations:

  • --cluster: The name of the cluster you created.
  • --region: The compute region you chose above.
  • --node-taints: The Kubernetes taints to automatically apply to nodes in this node pool.
  • --node-labels: The Kubernetes labels to automatically apply to nodes in this node pool.
  • --num-nodes: The number of nodes per cluster zone. For regional clusters, --num-nodes=1 creates one node in 3 separate zones in the region, giving you faster recovery time in the event of a node failure.
  • --machine-type: The type of machine to use for nodes. Default: e2-standard-4. Depending on the needs of your game, you may wish to have smaller or larger machines.

(Optional) Creating a metrics node pool

Create a node pool for Metrics if you want to monitor the Agones system using Prometheus with Grafana or Cloud Logging and Monitoring.

gcloud container node-pools create agones-metrics \
  --cluster=[CLUSTER_NAME] \
  --region=[COMPUTE_REGION] \
  --node-taints agones.dev/agones-metrics=true:NoExecute \
  --node-labels agones.dev/agones-metrics=true \
  --num-nodes=1 \
  --machine-type=e2-standard-4

Replace the following:

  • [CLUSTER_NAME]: The name of the cluster you created
  • [COMPUTE_REGION]: The GCP region to create the cluster in, chosen above

Flag explanations:

  • --cluster: The name of the cluster you created.
  • --region: The compute region you chose above.
  • --node-taints: The Kubernetes taints to automatically apply to nodes in this node pool.
  • --node-labels: The Kubernetes labels to automatically apply to nodes in this node pool.
  • --num-nodes: The number of nodes per cluster zone. For regional clusters, --num-nodes=1 creates one node in 3 separate zones in the region, giving you faster recovery time in the event of a node failure.
  • --machine-type: The type of machine to use for nodes. Default: e2-standard-4. Depending on the needs of your game, you may wish to have smaller or larger machines.

(Optional) Creating a node pool for Windows

If you run game servers on Windows, you need to create a dedicated node pool for those servers. Windows Server 2019 (WINDOWS_LTSC_CONTAINERD) is the recommended image for Windows game servers.

gcloud container node-pools create windows \
  --cluster=[CLUSTER_NAME] \
  --region=[COMPUTE_REGION] \
  --image-type WINDOWS_LTSC_CONTAINERD \
  --machine-type e2-standard-4 \
  --num-nodes=4

Replace the following:

  • [CLUSTER_NAME]: The name of the cluster you created
  • [COMPUTE_REGION]: The GCP region to create the cluster in, chosen above

Flag explanations:

  • --cluster: The name of the cluster you created.
  • --region: The compute region you chose above.
  • --image-type: The image type of the instances in the node pool - WINDOWS_LTSC_CONTAINERD in this case.
  • --machine-type: The type of machine to use for nodes. Default: e2-standard-4. Depending on the needs of your game, you may wish to have smaller or larger machines.
  • --num-nodes: The number of nodes per cluster zone. For regional clusters, --num-nodes=1 creates one node in 3 separate zones in the region, giving you faster recovery time in the event of a node failure.

Setting up cluster credentials

gcloud container clusters create configurates credentials for kubectl automatically. If you ever lose those, run:

gcloud container clusters get-credentials [CLUSTER_NAME] --region=[COMPUTE_REGION]

Next Steps


Last modified June 13, 2024: Change Slack channel description from #developers to #development (#3868) (b37fc35)