Number of clusters

Single-cluster: Gloo Mesh Core is fully functional when the management plane (management server) and data plane (agent and service mesh) both run within the same cluster. You can easily install both the control and data plane components by using one installation process. If you choose to install the components in separate processes, ensure that you use the same name for the cluster during both processes.

Multicluster: A multicluster Gloo Mesh Core setup consists of one management cluster that the Gloo Mesh Core management server is installed in, and one or more workload clusters that serves as the data plane (agent and service mesh). By running the management plane in a dedicated management cluster, you can ensure that no workload pods consume cluster resources that might impede management processes. Many guides throughout the documentation use one management cluster and two workload clusters as an example setup.

Cluster details

Review the following recommendations and considerations when creating clusters for your Gloo Mesh Core environment.

Name

The cluster name must be alphanumeric with no special characters except a hyphen (-), lowercase, and begin with a letter (not a number).

Cluster context names cannot include underscores. The generated certificate that connects workload clusters to the management cluster uses the context name as a SAN specification, and underscores in SAN are not FQDN compliant. You can rename a context by running kubectl config rename-context "<oldcontext>" <newcontext>.

Throughout the guides in this documentation, examples use a single-cluster setup and a three-cluster setup.

  • Single-cluster: When a guide requires an example name, the examples use mgmt. Otherwise, you can save the name of your cluster in the $CLUSTER_NAME environment variable, and the context of your cluster in the $MGMT_CONTEXT environment variable.
  • Multicluster: When a guide requires example names, the examples use mgmt, cluster1, and cluster2. Otherwise, you can save the names of your clusters in the $MGMT_CLUSTER, $REMOTE_CLUSTER1, and $REMOTE_CLUSTER2 environment variables, and the contexts of your clusters in the $MGMT_CONTEXT, $REMOTE_CONTEXT1, and $REMOTE_CONTEXT2 environment variables.

Version

The following versions of Gloo Mesh Core are supported with the compatible open source project versions of Istio and Kubernetes. Later versions of the open source projects that are released after Gloo Mesh Core might also work, but are not tested as part of the Gloo Mesh Core release.

Gloo Mesh CoreRelease dateSupported Solo distributions of Istio and related Kubernetes versions tested by Solo
2.615 Aug 2024
  • Istio 1.23 on Kubernetes 1.27 - 1.30
  • Istio 1.22 on Kubernetes 1.27 - 1.30
  • Istio 1.21 on Kubernetes 1.26 - 1.29
  • Istio 1.20 on Kubernetes 1.25 - 1.29
  • Istio 1.19 on Kubernetes 1.25 - 1.28
2.509 Jan 2024
  • Istio 1.20 on Kubernetes 1.25 - 1.29
  • Istio 1.19 on Kubernetes 1.25 - 1.28
  • Istio 1.18 on Kubernetes 1.24 - 1.27
  • Istio 1.17 on Kubernetes 1.23 - 1.26
  • Istio 1.16 on Kubernetes 1.22 - 1.25

Note: Istio 1.21 is not supported in Gloo Mesh Core version 2.5. You must upgrade the Gloo management server and agents to version 2.6 prior to upgrading to Istio 1.21.

Feature gates

To review the required Gloo Mesh Core versions for specific features that you can optionally enable, see Feature gates.

For more information, see Supported versions.

Load balancer connectivity

If you use an Istio ingress gateway and want to test connectivity through it in your Gloo environment, ensure that your cluster setup enables you to externally access LoadBalancer services on the workload clusters.

Port and repo access from cluster networks

If you have restrictions for your cluster networks in your cloud infrastructure provider, you must open ports, protocols, and image repositories to install Gloo Mesh Core and to allow your Gloo installation to communicate with the Solo APIs. For example, you might have firewall rules set up on the public network of your clusters so that they do not have default access to all public endpoints. The following sections detail the required and optional ports and repositories that your management and workload clusters must access.

Management cluster

Required

In your firewall or network rules for the management cluster, open the following required ports and repositories.

NamePortProtocolSourceDestinationNetworkDescription
Agent communication9900TCPClusterIPs of agents on workload clustersIP addresses of management cluster nodesCluster networkAllow the gloo-mesh-agent on each workload cluster to send data to the gloo-mesh-mgmt-server in the management cluster.
Management server images--IP addresses of management cluster nodeshttps://gcr.io/gloo-meshPublicAllow installation and updates of the gloo-mesh image in the management cluster.
Redis image--IP addresses of management cluster nodesdocker.io/redisPublicAllow installation of the Redis image in the management cluster to store OIDC ID tokens for the Gloo UI.

Optional

In your firewall or network rules for the management cluster, open the following optional ports as needed.

NamePortProtocolSourceDestinationNetworkDescription
Healthchecks8090TCPCheck initiatorIP addresses of management cluster nodesPublic or cluster network, depending on whether checks originate from outside or inside service meshAllow healthchecks to the management server.
OpenTelemetry gateway4317TCPOpenTelemetry agentIP addresses of management cluster nodesPublicCollect telemetry data, such as metrics, logs, and traces to show in Gloo observability tools.
Prometheus9091TCPScraperIP addresses of management cluster nodesPublicScrape your Prometheus metrics from a different server, or a similar metrics setup.
Other tools----PublicFor any other tools that you use in your Gloo environment, consult the tool’s documentation to ensure that you allow the correct ports. For example, if you use tools such as cert-manager to generate and manage the Gloo certificates for your setup, consult the cert-manager platform reference.

Workload clusters

Required

In your firewall or network rules for the workload clusters, open the following required ports and repositories.

NamePortProtocolSourceDestinationNetworkDescription
Agent image--IP addresses of workload cluster nodeshttps://gcr.io/gloo-meshPublicAllow installation and updates of the gloo-mesh image in workload clusters.
Ingress gateway80 and/or 443HTTP, HTTPS-Gateway load balancer IP addressPublic or private networkAllow incoming traffic requests to the Istio ingress gateway.

Optional

In your firewall or network rules for the workload clusters, open the following optional ports as needed.

NamePortProtocolSourceDestinationNetworkDescription
Agent healthchecks8090TCPCheck initiatorIP addresses of workload cluster nodesPublic or cluster network, depending on whether checks originate from outside or inside service meshAllow healthchecks to the Gloo agent.
Envoy telemetry15090HTTPScraperIP addresses of workload cluster nodesPublicScrape your Prometheus metrics from a different server, or a similar metrics setup.
Istio Pilot15017HTTPSIP addresses of workload cluster nodes-PublicDepending on your cloud provider, you might need to open ports to install Istio. For example, in GKE clusters, you must open port 15017 for the Pilot discovery validation webhook. For more ports and requirements, see Ports used by Istio.
Istio healthchecks15021HTTPCheck initiatorIP addresses of workload cluster nodesPublic or cluster network, depending on whether checks originate from outside or inside service meshAllow healthchecks on path /healthz/ready.
Solo distributions of Istio--IP addresses of workload cluster nodesA repo key for a Solo distribution of Istio that you can get by logging in to the Support Center and reviewing the Istio images built by Solo.io support articlePublicAllow installation and updates of the Solo distribution of Istio in workload clusters.

Port and repo access from local systems

If corporate network policies prevent access from your local system to public endpoints via proxies or firewall rules:

  • Allow access to https://run.solo.io/meshctl/install to install the meshctl CLI tool.
  • Allow access to the Gloo Helm repository, https://storage.googleapis.com/gloo-platform/helm-charts, to install Gloo Mesh Core via the helm CLI.

Reserved ports and pod requirements

Review the following service mesh and platform docs that outline what ports are reserved, so that you do not use these ports for other functions in your apps. You might use other services such as a database or application monitoring tool that reserve additional ports.

Considerations for running Cilium and Istio on EKS

If you plan to run Istio with sidecar injection and the Cilium CNI in tunneling mode (VXLAN or GENEVE) on an Amazon EKS cluster, the Istio control plane istiod is not reachable by the Kubernetes API server by default.

Istio uses Kubernetes admission webhooks to inject sidecar proxies into pods. In EKS environments, the Cilium CNI cannot run on the same nodes where the Kubernetes API server is deployed to, which leads to communication issues when trying to inject Istio sidecars into pods.

You can choose from the following options to allow istiod to communicate with the Kubernetes API server:

  • Configure istiod with direct access to the networking stack of the underlying host node by setting hostNetwork to true as shown in the following Istio Lifecycle Manager example:
      # Traffic management
        components:
          pilot:
            k8s:
              overlays:
                - kind: Deployment
                  name: istiod-1-23
                  patches:
                    - path: spec.template.spec.hostNetwork
                      value: true 
      
  • Chain the Cilium CNI with the aws-vpc-cni. For more information, see the Cilium documentation.
  • Choose a different Cilium routing mode instead, such as eBPF-based routing. For more information about available modes, see the Cilium documentation.
  • Consider running Istio in ambient mode. For more information, see Beta: Ambient mesh.