Deploy Consul Service Mesh on Kubernetes

This tutorial covers the necessary steps to install and configure Consul service mesh on an existing Kubernetes cluster.

By the end of this tutorial, you will be able to identify the installation prerequisites, download and configure the official Helm chart for Consul, and deploy Consul service mesh in your Kubernetes cluster.

Security Warning: This tutorial is not for production use. By default, the chart will install an insecure configuration of Consul. Please refer to the Kubernetes documentation to determine how you can secure Consul on Kubernetes in production. Additionally, it is highly recommended to use a properly secured Kubernetes cluster or make sure that you understand and enable the recommended security features.

»Prerequisites

• Helm locally to deploy your Consul service mesh.
• kubectl locally to interact with your Kubernetes cluster and deploy services.

NOTE: A similar, Minikube based interactive hands-on lab is also available if you do not have a Consul environment to perform the steps described in this tutorial. Click the Show Tutorial button to launch the lab experience.

»Configure kubectl to talk to your cluster

$ export KUBECONFIG="$HOME/.kube/config"

Before continuing, you should test that the kubectl is configured to interact with your Kubernetes cluster by using kubectl get pods to query for pods.

$ kubectl get pods --all-namespaces

NAMESPACE     NAME                               READY   STATUS    RESTARTS   AGE
kube-system   coredns-66bff467f8-vldj2           1/1     Running   0          42s
kube-system   etcd-minikube                      1/1     Running   0          48s
kube-system   kube-apiserver-minikube            1/1     Running   0          48s
kube-system   kube-controller-manager-minikube   1/1     Running   0          48s
kube-system   kube-proxy-cm78b                   1/1     Running   0          43s
kube-system   kube-scheduler-minikube            1/1     Running   0          48s
kube-system   storage-provisioner                1/1     Running   1          48s

»Get the official Helm chart

Consul offers first-class Kubernetes support by providing an official Helm chart. The chart helps you automate the installation and configuration of Consul’s core features for Kubernetes, listed below.

• Auto-join for Kubernetes. Consul's cloud auto-join feature supports discovering and joining Kubernetes-based agents. This enables external Consul agents in different datacenters to join a Consul datacenter running in Kubernetes.
• Service Catalog Sync:
  • Kubernetes to Consul. Kubernetes services will be automatically synced to the Consul catalog, enabling non-Kubernetes services to discover and connect to services running within Kubernetes. The Kubernetes services will be discoverable with the Consul UI, CLI, and API.
  • Consul to Kubernetes. Consul services will be synced to Kubernetes services so that applications can use Kubernetes-native service discovery to discover and connect to services running outside of Kubernetes. The non-Kubernetes services will be discoverable with the Kubernetes UI and kubectl.
• Connect Auto-Inject. Pods deployed in Kubernetes can be configured to automatically use Consul to securely communicate using mutual TLS.

To deploy Consul service mesh using Helm you need a copy of the official chart.

helm repo add hashicorp https://helm.releases.hashicorp.com

"hashicorp" has been added to your repositories

»Configure the Helm chart

The Helm chart repository contains a values.yaml file that illustrates all possible configuration values. For this tutorial, you will create your own consul-values.yml file and pass it to helm install with the -f flag, e.g. helm install -f consul-values.yml hashicorp hashicorp/consul.

The Shipyard blueprint provides a sample configuration file located at helm-charts/consul-values.yml. You can use that file, or export the example below to provision Consul as your Kubernetes service mesh; however, you should consider your particular production needs when configuring your chart for production environments.

$ cat > consul-values.yml <<EOF
global:
  domain: consul
  datacenter: dc1

server:
  replicas: 1
  bootstrapExpect: 1

client:
  enabled: true
  grpc: true

ui:
  enabled: true

connectInject:
  enabled: true
EOF

You can find additional details on the different configuration options in the sections below.

»Global configuration

The values under the global key will affect all the other parameters in the chart.

• datacenter is the name of your Consul datacenter.
• domain is the domain Consul uses for DNS queries.

»Server and client configuration

The server key contains parameters related to the server pods. The chart is configured to create one Consul server per Kubernetes node.

The blueprint used for this tutorial creates a single node Kubernetes cluster so the configuration creates one replica and sets bootstrapExpect :1.

A Consul client is deployed on every Kubernetes node, so you do not need to specify the number of clients for your deployments. However, you will need to specify resources.

»Consul UI configuration

To enable the Consul web UI update the ui section and set enabled to true.

Note, you can also set up a LoadBalancer resource or other service type in Kubernetes to make it easier to access the UI.

»Consul connectInject security configuration

You can enable the Consul Connect service mesh by setting the connectInject key to true.

When the Connect injector is installed, then a sidecar proxy is automatically added to all pods. This sidecar can both accept and establish connections using Consul, thus enabling the pod to communicate with clients and dependencies exclusively over authorized and encrypted connections.

»Deploy Consul service mesh

You will use helm install to deploy Consul using the configuration defined in consul-values.yml. This should only take a few minutes. The Consul pods should appear in the Kubernetes dashboard immediately and you can monitor the deployment process there.

$ helm install -f consul-values.yml hashicorp hashicorp/consul

NAME: hashicorp
## ...
NAMESPACE: default
STATUS: deployed
REVISION: 1
NOTES:
Thank you for installing HashiCorp Consul!

Now that you have deployed Consul, you should look over the docs on using
Consul with Kubernetes available here:

https://www.consul.io/docs/platform/k8s/index.html

Your release is named hashicorp. To learn more about the release, try:

  $ helm status hashicorp
  $ helm get hashicorp

To check the deployment process on the command line you can use kubectl get pods --all-namespaces to get the list of pods created or use kubectl get services to get a list of services running in the Kubernetes cluster.

$ kubectl get services

NAME                                    TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)                                                                   AGE
kubernetes                              ClusterIP   10.43.0.1     <none>        443/TCP                                                                   22m
hashicorp-consul-server                 ClusterIP   None          <none>        8500/TCP,8301/TCP,8301/UDP,8302/TCP,8302/UDP,8300/TCP,8600/TCP,8600/UDP   15m
hashicorp-consul-connect-injector-svc   ClusterIP   10.43.2.103   <none>        443/TCP                                                                   15m
hashicorp-consul-dns                    ClusterIP   10.43.22.2    <none>        53/TCP,53/UDP                                                             15m
hashicorp-consul-ui                     ClusterIP   10.43.85.85   <none>        80/TCP                                                                    15m

»Interact with Consul service mesh

Depending on the Kubernetes flavor you are using to test Consul service mesh you have different options for enabling access to the Consul UI.

$ kubectl port-forward service/hashicorp-consul-ui 18500:80 --address 0.0.0.0

»Access Consul UI

Once access is configured, the Consul UI will be available at http://localhost:18500.

Explore the Consul UI by viewing the nodes and services tabs.

»Access Consul containers

You can use kubectl exec to get direct access to any container, including Consul containers.

$ kubectl exec -it hashicorp-consul-server-0 -- /bin/sh

/#

Once you have access to one of the Consul agents, use the consul command to interact with your datacenter.

$ consul members

Example output:

Node                       Address          Status  Type    Build  Protocol  DC   Segment
hashicorp-consul-server-0  172.17.0.5:8301  alive   server  1.8.2  2         dc1  <all>
minikube                   172.17.0.3:8301  alive   client  1.8.2  2         dc1  <default>

»Using Consul environment variable

If you have the consul binary installed on your test machine, you can interact with the datacenter directly.

Set the CONSUL_HTTP_ADDR to point to the ingress you created earlier in the tutorial.

$ export CONSUL_HTTP_ADDR="http://localhost:18500"

You can now use the consul command locally to interact with your datacenter.

$ consul members

Example output:

Node                       Address          Status  Type    Build  Protocol  DC   Segment
hashicorp-consul-server-0  172.17.0.5:8301  alive   server  1.8.2  2         dc1  <all>
minikube                   172.17.0.3:8301  alive   client  1.8.2  2         dc1  <default>

»Next steps

In this tutorial, you configured Consul Connect service mesh on an existing Kubernetes cluster using the official Helm chart. You enabled the UI and enabled external access to the service. Finally, you used kubectl to interact with your service mesh.

In the next tutorial, Secure Applications with Consul Service Mesh, you will learn how to deploy Connect service mesh enabled services on Kubernetes using Envoy as sidecar proxy.