Deploy Consul on Kubernetes
Consul is a service networking solution that enables teams to manage secure network connectivity between services and across on-prem and multi-cloud environments and runtimes. Consul offers service discovery, service mesh, traffic management, and automated updates to network infrastructure devices. Check out the What is Consul? page to learn more.
In this tutorial, you will deploy a Consul datacenter onto a Kubernetes cluster. After deploying Consul, you will interact with Consul using the UI and CLI.
In the following tutorials, you will deploy a demo application, integrate it with Consul service mesh, allow external traffic into the service mesh, and enhance observability into your service mesh.
In this tutorial, you will:
- Deploy an Elastic Kubernetes Service (EKS) cluster with Terraform
- Install Consul using Helm or the Consul K8S CLI
- Configure your terminal to communicate with the Consul datacenter
- View Consul services with the CLI, UI, and/or API
Prerequisites
For this tutorial, you will need:
Clone GitHub repository
Clone the GitHub repository containing the configuration files and resources.
$ git clone https://github.com/hashicorp-education/learn-consul-get-started-kubernetes
Change into the directory that contains the complete configuration files for this tutorial.
$ cd learn-consul-get-started-kubernetes/self-managed/eks
Create infrastructure
With these Terraform configuration files, you are ready to deploy your infrastructure.
Issue the terraform init
command from your working directory to download the necessary providers and initialize the backend.
$ terraform init Initializing the backend... Initializing provider plugins...... Terraform has been successfully initialized!...
Then, deploy the resources. Confirm the run by entering yes
.
$ terraform apply ## ...Do you want to perform these actions? Terraform will perform the actions described above. Only 'yes' will be accepted to approve. Enter a value: yes ## ... Apply complete! Resources: 55 added, 0 changed, 0 destroyed.
Note: The Terraform deployment could take up to 10 minutes to complete. Feel free to explore the next sections of this tutorial while waiting for the environment to complete initialization or learn more about the Raft protocol in a fun, interactive way.
Connect to your infrastructure
Kubernetes stores cluster connection information in a file called kubeconfig
. You can retrieve the Kubernetes configuration settings for your EKS cluster and merge them into your local kubeconfig
file by issuing the following command:
$ aws eks --region $(terraform output -raw region) update-kubeconfig --name $(terraform output -raw kubernetes_cluster_id)
Deploy Consul datacenter
Review Consul server configuration
You will now review the Helm chart for deploying a Consul datacenter in your Kubernetes cluster using the consul-k8s
CLI or Helm installation methods.
To deploy Consul on Kubernetes, go directly to Deploy Consul.
Review helm/values-v1.yaml
. This file defines the Consul datacenter you will deploy to Kubernetes. Review the comments in the file for an explanation of each parameter.
helm/values-v1.yaml
# Contains values that affect multiple components of the chart.global: # The main enabled/disabled setting. # If true, servers, clients, Consul DNS and the Consul UI will be enabled. enabled: true # The prefix used for all resources created in the Helm chart. name: consul # The consul image version. image: hashicorp/consul:1.16.0 # The name of the datacenter that the agents should register as. datacenter: dc1 # Enables TLS across the cluster to verify authenticity of the Consul servers and clients. tls: enabled: true # Enables ACLs across the cluster to secure access to data and APIs. acls: # If true, automatically manage ACL tokens and policies for all Consul components. manageSystemACLs: true# Configures values that configure the Consul server cluster.server: enabled: true # The number of server agents to run. This determines the fault tolerance of the cluster. replicas: 3# Contains values that configure the Consul UI.ui: enabled: true # Registers a Kubernetes Service for the Consul UI as a LoadBalancer. service: type: LoadBalancer# Configures and installs the automatic Consul Connect sidecar injector.connectInject: enabled: true
For a complete list of Helm chart parameters and configuration, refer to the Consul Helm chart documentation.
Deploy Consul datacenter
Deploy a Consul datacenter to your Kubernetes environment with the Consul K8S CLI or Helm.
Install Consul to your Kubernetes cluster with the Consul K8S CLI. Confirm the run by entering y
.
$ consul-k8s install -config-file=helm/values-v1.yaml## ... Proceed with installation? (y/N) y==> Installing Consul## ...✓ Consul installed in namespace "consul".
Notice that the Consul K8s CLI installs Consul into the consul
namespace.
Refer to the Consul K8S CLI documentation to learn more about additional settings.
Configure your CLI to interact with Consul datacenter
In this section, you will set environment variables in your terminal so your Consul CLI can interact with your Consul datacenter. The Consul CLI reads these environment variables for behavior defaults and will reference these values when you run consul
commands.
Tokens are artifacts in the ACL system used to authenticate users, services, and Consul agents. Since ACLs are enabled in this Consul datacenter, entities requesting access to a resource must include a token that is linked with a policy, service identity, or node identity that grants permission to the resource. The ACL system checks the token and grants or denies access to resources based on the associated permissions. A bootstrap token has unrestricted privileges to all resources and APIs.
Retrieve the ACL bootstrap token from the respective Kubernetes secret and set it as an environment variable.
$ export CONSUL_HTTP_TOKEN=$(kubectl get --namespace consul secrets/consul-bootstrap-acl-token --template={{.data.token}} | base64 -d)
Set the Consul destination address. By default, Consul runs on port 8500
for http
and 8501
for https
.
$ export CONSUL_HTTP_ADDR=https://$(kubectl get services/consul-ui --namespace consul -o jsonpath='{.status.loadBalancer.ingress[0].hostname}')
Remove SSL verification checks to simplify communication to your Consul datacenter.
$ export CONSUL_HTTP_SSL_VERIFY=false
Note: In a production environment, we recommend keeping this SSL verification set to true
. Only remove this verification for if you have a Consul datacenter without TLS configured in development environment and demonstration purposes.
View Consul services
In this section, you will view your Consul services with the CLI, UI, and/or API to explore the details of your service mesh.
In your terminal, run the CLI command consul catalog services
to return the list of services registered in Consul. Notice this returns only the consul
service since it is the only running service in your Consul datacenter.
$ consul catalog servicesconsul
Agents run in either server or client mode. Server agents store all state information, including service and node IP addresses, health checks, and configuration. Client agents are lightweight processes that make up the majority of the datacenter. They report service health status to the server agents. Clients must run on every pod where services are running.
Run the CLI command consul members
to return the list of Consul agents in your environment.
$ consul membersNode Address Status Type Build Protocol DC Partition Segmentconsul-server-0 10.0.4.13:8301 alive server 1.16.0 2 dc1 default <all>consul-server-1 10.0.6.43:8301 alive server 1.16.0 2 dc1 default <all>consul-server-2 10.0.5.64:8301 alive server 1.16.0 2 dc1 default <all>
All services listed in your Consul catalog are empowered with Consul's service discovery capabilities that simplify scalability challenges and improve application resiliency. Review the Service Discovery overview page to learn more.
Next steps
In this tutorial, you integrated Consul into your Kubernetes environment. After deploying Consul, you interacted with Consul using the CLI, UI, and API.
In the next tutorial, you will deploy HashiCups, a demo application, onto your Kubernetes cluster to explore how to use Consul service mesh for service-to-service traffic management.
For more information about the topics covered in this tutorial, refer to the following resources: