Setting up Gateway API

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Updated at September 3, 2024

Getting started
Create Managed Service for Kubernetes resources
Install the Gateway API and set up the domain zones
Prepare test applications
Test Gateway API
Delete the resources you created

Gateway API is a collection of API resources that model networking in a Kubernetes cluster.

In this tutorial, you will learn how to enable access to the applications deployed in two test environments, dev and prod, by running Yandex Application Load Balancer with Gateway API. For this you will need to create a public domain zone and delegate the domain to Yandex Cloud DNS.

To integrate Gateway API and Application Load Balancer:

If you no longer need the resources you created, delete them.

Getting started

If you do not have the Yandex Cloud command line interface yet, install and initialize it.

The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.
Register a public domain zone and delegate your domain.

Create Managed Service for Kubernetes resources

Create a Kubernetes cluster and a group of nodes.
Manually

Terraform
1. If you do not have a network yet, create one.
2. If you do not have any subnets yet, create them in the availability zones where your Kubernetes cluster and node group will be created.
3. Create security groups for the Managed Service for Kubernetes cluster and its node groups.
  
  Warning
  
  The configuration of security groups determines the performance and availability of the cluster and the services and applications running in it.
4. Create a Kubernetes cluster and a node group in any suitable configuration. When creating them, specify the security groups prepared earlier.
1. If you do not have Terraform yet, install it.
2. Get the authentication credentials. You can add them to environment variables or specify them later in the provider configuration file.
3. Configure and initialize a provider. There is no need to create a provider configuration file manually, you can download it.
4. Place the configuration file in a separate working directory and specify the parameter values. If you did not add the authentication credentials to environment variables, specify them in the configuration file.
5. Download the k8s-gateway-api.tf cluster configuration file to the same working directory. The file describes:
  - Network.
  - Subnet.
  - Kubernetes cluster.
  - Service account required for the Kubernetes cluster and node group to operate.
  - Security groups which contain rules required for the Managed Service for Kubernetes cluster and its node groups.
    
    Warning
    
    The configuration of security groups determines the performance and availability of the cluster and the services and applications running in it.
6. Specify the following in the configuration file:
  - Folder ID.
  - Kubernetes version for the Kubernetes cluster and node groups.
  - Kubernetes cluster CIDR.
7. Make sure the Terraform configuration files are correct using this command:
  terraform validate
  If there are any errors in the configuration files, Terraform will point them out.
8. Create the required infrastructure:
  1. Run the command to view planned changes:
    
    terraform plan
    
    If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.
  2. If you are happy with the planned changes, apply them:
    
    Run the command:
    
    terraform apply
    
    Confirm the update of resources.
    
    Wait for the operation to complete.
  All the required resources will be created in the specified folder. You can check resource availability and their settings in the management console.
Install kubectl and configure it to work with the created cluster.
Create a service account required for Gateway API:
Assign the following roles to it:
- alb.editor: To create the required resources.
- certificate-manager.admin: To use certificates registered in Yandex Certificate Manager.
- compute.viewer: To use Managed Service for Kubernetes cluster nodes in the load balancer target groups.
- vpc.publicAdmin: To manage external connectivity.

Create a static key and save it to a file named sa-key.json:

yc iam key create \
  --service-account-name <name_of_service_account_for_Gateway_API> \
  --output sa-key.json

Install the Gateway API and set up the domain zones

Install the Gateway API application according to the instructions. During the installation, use the service account key issued previously.

Reserve the public IP addresses for the prod and dev test environments:

yc vpc address create \
  --name=prod \
  --labels reserved=true \
  --external-ipv4 \
  zone=<availability_zone> && \
yc vpc address create \
  --name=dev \
  --labels reserved=true \
  --external-ipv4 \
  zone=<availability_zone>

Where availability_zone is the availability zone hosting your Kubernetes cluster.

Save the public IP addresses: you will need them to continue the setup.

Add resource records for your public DNS zone:

yc dns zone add-records \
  --name <DNS_zone_name> \
  --record '*.prod 60 A <prod_environment_IP_address>' && \
yc dns zone add-records \
  --name <DNS_zone_name> \
  --record '*.dev 60 A <dev_environment_IP_address>'

Example of a valid command:

yc dns zone add-records \
 --name my-domain-name \
 --record '*.dev 60 A 171.154.241.41'

Create a namespace for TLS secrets:

kubectl create namespace gateway-api-tls-secrets

Create OpenSSL certificates:

openssl req -x509 \
  -newkey rsa:4096 \
  -keyout gateway-key-prod.pem \
  -out gateway-cert-prod.pem \
  -nodes \
  -days 365 \
  -subj '/CN=*.prod.<domain_zone>' && \
openssl req -x509 \
   -newkey rsa:4096 \
   -keyout gateway-key-dev.pem \
   -out gateway-cert-dev.pem \
   -nodes \
   -days 365 \
   -subj '/CN=*.dev.<domain_zone>'

Example of a valid command:

openssl req -x509 \
 -newkey rsa:4096 \
 -keyout gateway-key-prod.pem \
 -out gateway-cert-prod.pem \
 -nodes \
 -days 365 \
 -subj '/CN=*.prod.my-test-domain.com'

Based on these certificates, secrets will be created for the prod and dev test environments in the Kubernetes cluster.

Create the secrets:

kubectl create -n gateway-api-tls-secrets secret tls gateway-prod-tls \
  --cert=gateway-cert-prod.pem \
  --key=gateway-key-prod.pem && \
kubectl create -n gateway-api-tls-secrets secret tls gateway-dev-tls \
  --cert=gateway-cert-dev.pem \
  --key=gateway-key-dev.pem

Prepare test applications

Two applications will be created to test the Gateway API: tutum/hello-world and nginxdemos/hello. For each application, you will need to configure and run three YAML files:

dev-gw.yaml and prod-gw.yaml: Settings for the Gateway. In these manifest files, specify:
- Security groups in which your Kubernetes cluster is deployed in the metadata.annotations.gateway.alb.yc.io/security-groups parameter.
- Domain zone, with the *.dev and *.prod prefixes in the hostname parameters.
- IP addresses for the dev and prod environments in the spec.addresses.value parameter.
dev-route.yaml and prod-route.yaml: Routing settings for the applications. In these manifests, you need to specify the domain zone with the app.dev and app.prod prefixes in the spec.hostnames parameter.
dev-app.yaml and prod-app.yaml: Settings for the applications. These manifests will be used to create:
- Namespace (unique for each application)
- Deployment for the application
- Service

Configure the application for the dev environment

Create the dev-gw.yaml manifest file:

dev-gw.yaml

---
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: Gateway
metadata:
  name: gateway-api-dev
  annotations:
    gateway.alb.yc.io/security-groups: <cluster_security_group_IDs>
spec:
  gatewayClassName: yc-df-class
  listeners:
  - name: gateway-api-dev
    protocol: HTTP
    port: 80
    hostname: "*.dev.<domain_zone>"
    allowedRoutes:
      namespaces:
        from: Selector
        selector:
          matchExpressions:
          - key: kubernetes.io/metadata.name
            operator: In
            values:
            - dev-app
  - name: gateway-api-dev-tls
    protocol: HTTPS
    port: 443
    hostname: "*.dev.<domain_zone>"
    allowedRoutes:
      namespaces:
        from: Selector
        selector:
          matchExpressions:
          - key: kubernetes.io/metadata.name
            operator: In
            values:
            - dev-app
    tls:
      certificateRefs:
      - group: ""
        kind: Secret
        name: gateway-dev-tls
        namespace: gateway-api-tls-secrets
      mode: Terminate
  addresses:
   - type: IPAddress
     value: "<dev_environment_IP_address>"

Create the dev-route.yaml file:

dev-route.yaml

---
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: HTTPRoute
metadata:
  name: dev-app-http-route
  namespace: dev-app
spec:
  hostnames:
  - "app.dev.<domain_zone>"
  parentRefs:
  - name: gateway-api-dev
    namespace: default
  rules:
  - matches:
    - path:
        value: /
    backendRefs:
    - name: app
      port: 80

Create the dev-app.yaml manifest file:

dev-app.yaml

---
apiVersion: v1
kind: Namespace
metadata:
  name: dev-app
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: app
  namespace: dev-app
spec:
  selector:
    matchLabels:
      app: app
  template:
    metadata:
      labels:
        app: app
    spec:
      containers:
      - name: app
        image: tutum/hello-world
        resources:
          limits:
            memory: "128Mi"
            cpu: "500m"
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: app
  namespace: dev-app
spec:
  type: NodePort
  selector:
    app: app
  ports:
  - port: 80
    targetPort: 80

Configure the application for the prod environment

Create the dev-prod.yaml manifest file:

prod-gw.yaml

---
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: Gateway
metadata:
  name: gateway-api-prod
  annotations:
    gateway.alb.yc.io/security-groups: <cluster_security_group_IDs>
spec:
  gatewayClassName: yc-df-class
  listeners:
  - name: gateway-api-prod
    protocol: HTTP
    port: 80
    hostname: "*.prod.<domain_zone>"
    allowedRoutes:
      namespaces:
        from: Selector
        selector:
          matchExpressions:
          - key: kubernetes.io/metadata.name
            operator: In
            values:
            - prod-app
  - name: gateway-api-prod-tls
    protocol: HTTPS
    port: 443
    hostname: "*.prod.<domain_zone>"
    allowedRoutes:
      namespaces:
        from: Selector
        selector:
          matchExpressions:
          - key: kubernetes.io/metadata.name
            operator: In
            values:
            - prod-app
    tls:
      certificateRefs:
      - group: ""
        kind: Secret
        name: gateway-prod-tls
        namespace: gateway-api-tls-secrets
      mode: Terminate
  addresses:
    - type: IPAddress
      value: "<prod_environment_IP_address>"

Create the prod-route.yaml manifest file:

prod-route.yaml

---
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: HTTPRoute
metadata:
  name: prod-app-http-route
  namespace: prod-app
spec:
  hostnames:
  - "app.prod.<domain_zone>"
  parentRefs:
  - name: gateway-api-prod
    namespace: default
  rules:
  - matches:
    - path:
        value: /
    backendRefs:
    - name: app
      port: 80

Create the prod-app.yaml manifest file:

prod-app.yaml

---
apiVersion: v1
kind: Namespace
metadata:
  name: prod-app
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: app
  namespace: prod-app
spec:
  selector:
    matchLabels:
      app: app
  template:
    metadata:
      labels:
        app: app
    spec:
      containers:
      - name: app
        image: tutum/hello-world
        resources:
          limits:
            memory: "128Mi"
            cpu: "500m"
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: app
  namespace: prod-app
spec:
  type: NodePort
  selector:
    app: app
  ports:
  - port: 80
    targetPort: 80

Create test applications

To install the applications, run this command:

kubectl apply -f prod-gw.yaml && \
kubectl apply -f prod-app.yaml && \
kubectl apply -f prod-route.yaml && \
kubectl apply -f dev-gw.yaml && \
kubectl apply -f dev-app.yaml && \
kubectl apply -f dev-route.yaml

Make sure that the application pods have entered the Running state:

kubectl get pods --namespace dev-app && \
kubectl get pods --namespace prod-app

Make sure that a load balancer has been created for the Gateway API:
```
yc application-load-balancer load-balancer list
```
Note

It may take several minutes to create the load balancer.

Test Gateway API

To test Gateway API, open these links in your browser:

app.prod.<domain_zone>
app.dev.<domain_zone>

Note

If the resource is unavailable at the specified URL, make sure that the security groups for the Managed Service for Kubernetes cluster and its node groups are configured correctly. If any rule is missing, add it.

Delete the resources you created

Some resources are not free of charge. To avoid paying for them, delete the resources you no longer need:

Manually

Terraform

In the command line, go to the directory with the current Terraform configuration file with an infrastructure plan.
Delete the k8s-gateway-api.tf configuration file.
Make sure the Terraform configuration files are correct using this command:
```
terraform validate
```
If there are any errors in the configuration files, Terraform will point them out.
Confirm updating the resources.
1. Run the command to view planned changes:
```
terraform plan
```
  If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.
2. If you are happy with the planned changes, apply them:
  1. Run the command:
```
terraform apply
```
  2. Confirm the update of resources.
  3. Wait for the operation to complete.
All the resources described in the k8s-gateway-api.tf configuration file will be deleted.

Setting up Gateway API

Getting startedGetting started

Create Managed Service for Kubernetes resourcesCreate Managed Service for Kubernetes resources

Install the Gateway API and set up the domain zonesInstall the Gateway API and set up the domain zones

Prepare test applicationsPrepare test applications

Configure the application for the dev environmentConfigure the application for the dev environment

Configure the application for the prod environmentConfigure the application for the prod environment

Create test applicationsCreate test applications

Test Gateway APITest Gateway API

Delete the resources you createdDelete the resources you created

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