In this tutorial, you will enable external access into your service mesh by deploying a Consul API Gateway. Consul API Gateway provides a consistent method to handle inbound requests and route them to the appropriate service within your service mesh. To set up ingress into your service mesh, you will:
- Enable Consul ingress features
- Deploy Consul API Gateway
- Deploy RBAC and Reference Grant resources
- View Consul services with the CLI, UI, and/or API
- Explore ingress into the HashiCups UI
The tutorial assumes that you have completed the previous tutorials in this getting started collection.
For this tutorial, you will need:
- consul >= 1.14.0
- consul-k8s >= 1.0.0
- docker >= 20.0
- git >= 2.0
- helm >= 3.0
- kind <= 0.24.x
- kubectl <= 1.24
You will now enable additional Consul features in your Kubernetes cluster using the official Consul Helm chart or the
Consul API Gateway implements and is configured through the Kubernetes Gateway API Specification. This specification defines a set of custom resource definitions (CRDs) that can create logical gateways which route traffic based on a client request's path or protocol.
First, create the custom resource definitions (CRD) for the API Gateway Controller.
$ kubectl apply --kustomize "github.com/hashicorp/consul-api-gateway/config/crd?ref=v0.5.0" customresourcedefinition.apiextensions.k8s.io/gatewayclassconfigs.api-gateway.consul.hashicorp.com created customresourcedefinition.apiextensions.k8s.io/gatewayclasses.gateway.networking.k8s.io created customresourcedefinition.apiextensions.k8s.io/gateways.gateway.networking.k8s.io created customresourcedefinition.apiextensions.k8s.io/httproutes.gateway.networking.k8s.io created customresourcedefinition.apiextensions.k8s.io/meshservices.api-gateway.consul.hashicorp.com created customresourcedefinition.apiextensions.k8s.io/referencepolicies.gateway.networking.k8s.io created customresourcedefinition.apiextensions.k8s.io/tcproutes.gateway.networking.k8s.io created customresourcedefinition.apiextensions.k8s.io/tlsroutes.gateway.networking.k8s.io created customresourcedefinition.apiextensions.k8s.io/udproutes.gateway.networking.k8s.io created
Review the additional configuration details.
# Contains values that affect multiple components of the chart. global: ## ... # Configures and installs the Consul API Gateway. apiGateway: enabled: true # Image to use for the api-gateway-controller pods and gateway instances image: "hashicorp/consul-api-gateway:0.5.0" # Configuration settings for the GatewayClass managedGatewayClass: # Defines the type of service created for gateways (e.g. LoadBalancer, ClusterIP, NodePort) # NodePort is primarily used for local deployments. serviceType: NodePort # Toggles the gateway ports to be mapped to host ports (used for local deployments) useHostPorts: true
Update Consul in your Kubernetes cluster with Consul K8S CLI. Confirm the run by entering
$ consul-k8s upgrade -config-file=helm/values-v2.yaml -set global.image=hashicorp/consul:1.14.0
Refer to the Consul K8S CLI documentation to learn more about additional settings.
Now that you have enabled ingress features in your Consul service mesh, you can deploy the Consul API Gateway and associated HTTP Routes to your Kubernetes cluster. The Consul API Gateway uses HTTP Routes to route traffic to your applications.
api-gw/consul-api-gateway.yaml configuration file. This file contains the configuration for the API Gateway pod, the listener, and TLS attributes.
apiVersion: gateway.networking.k8s.io/v1alpha2 # The Gateway is the main infrastructure resource that links API gateway components. kind: Gateway metadata: name: api-gateway namespace: consul spec: gatewayClassName: consul-api-gateway # Configures the listener that is bound to the gateway's address. listeners: # Defines the listener protocol (HTTP, HTTPS, or TCP) - protocol: HTTPS port: 8443 name: https allowedRoutes: namespaces: from: Same tls: # Defines the certificate to use for the HTTPS listener. certificateRefs: - name: consul-server-cert
api-gw/routes.yaml configuration file. This file contains the configuration for HTTP routing including the network traffic rules and the backend service that will receive the ingress traffic.
apiVersion: gateway.networking.k8s.io/v1alpha2 # HTTPRoute routes HTTP requests to backend services. kind: HTTPRoute metadata: name: http-route-1 namespace: consul spec: # Defines the gateway listener. parentRefs: - name: api-gateway # Rules define behaviors for network traffic that goes through the route. rules: - matches: - path: type: PathPrefix value: / # Defines the backend service. backendRefs: - kind: Service name: nginx namespace: default port: 80
Next, deploy the API Gateway, wait for the API Gateway to completely deploy, and deploy the routes.
$ kubectl apply --filename api-gw/consul-api-gateway.yaml --namespace consul && \ kubectl wait --for=condition=ready gateway/api-gateway --namespace consul --timeout=90s && \ kubectl apply --filename api-gw/routes.yaml --namespace consul
gateway.gateway.networking.k8s.io/api-gateway created gateway.gateway.networking.k8s.io/api-gateway condition met httproute.gateway.networking.k8s.io/http-route-1 created
Verify you have created all the pods in your
consul namespace. You should find an output similar to the following.
$ kubectl get pods --namespace consul | grep "api-gateway" NAME READY STATUS RESTARTS AGE api-gateway-6ddbd69979-bm5kq 1/1 Running 0 64s consul-api-gateway-controller-66dddfb4c8-jj8w2 1/1 Running 1 7m9s
The diagram below shows the services running in your Kubernetes cluster. This includes Consul API Gateway, service mesh layer, and HashiCups microservice application pods.
Consul API Gateway enables ingress, load-balancing, and other advanced traffic behavior for your service mesh applications. In this tutorial, Consul API Gateway allows external traffic into the HashiCups service.
Now that Consul API Gateway is operational in your cluster, you will deploy role-based access control (RBAC) and Reference Grant resources. RBAC enables the Consul API gateway to interact with Consul cluster resources and reference grants enable the Consul API Gateway to route traffic between different namespaces.
Deploy the RBAC and Reference Grant resources.
$ kubectl apply --filename hashicups/v2/ clusterrolebinding.rbac.authorization.k8s.io/consul-api-gateway-tokenreview-binding created clusterrole.rbac.authorization.k8s.io/consul-api-gateway-auth created clusterrolebinding.rbac.authorization.k8s.io/consul-api-gateway-auth-binding created clusterrolebinding.rbac.authorization.k8s.io/consul-auth-binding created referencegrant.gateway.networking.k8s.io/consul-reference-grant created
In this section, you will view your Consul services with the CLI, UI, and/or API to explore the details of your service mesh ingress.
Open a separate terminal window and expose the Consul server with
kubectl port-forward using the
consul-ui service name as the target.
$ kubectl port-forward svc/consul-ui --namespace consul 8501:443
In your original terminal, run the CLI command
consul catalog services to return the
api-gateway service registered in Consul.
$ consul catalog services | grep api-gateway api-gateway
Return the list of Consul intentions. Consul automatically creates intentions between the Consul API Gateway and any destination services defined in your route configuration files. In this case, it created an intention to allow traffic from
$ consul intention list ID Source Action Destination Precedence api-gateway allow nginx 9 nginx allow frontend 9 nginx allow public-api 9 product-api allow product-api-db 9 public-api allow payments 9 public-api allow product-api 9
Retrieve information on the
$ kubectl get services api-gateway --namespace consul NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE api-gateway NodePort 10.96.214.246 <none> 8443:31800/TCP 8m7s
In this local environment, API Gateway uses NodePort to let you access your application directly through the API Gateway without having to forward your Kubernetes cluster’s ports. In a cloud environment, API Gateway may use a LoadBalancer to automatically provision a publicly accessible DNS entry.
Access the HashiCups UI through the API Gateway by opening https://localhost:8443 in your browser.
For more information on accessing service mesh services via the Consul API Gateway, visit the Consul API Gateway documentation page.
In this tutorial, you enabled Consul ingress features and deployed Consul API Gateway into your Kubernetes cluster. After deploying Consul API Gateway, you accessed the demo application HashiCups through the Consul API Gateway endpoint and explored how ingress into a service mesh application works.
In the next tutorial, you will deploy an observability suite to explore metrics, logs, and distributed traces within your Consul service mesh.
For more information about the topics covered in this tutorial, refer to the following resources: