k8s-gateway-api-playground

Let's play with GatewayAPI!

• k8s-gateway-api-playground
• Experience path
  • Primer
  • Ingress exercise
  • Gateway API exercise

Experience path

Primer

1. Provision GKE Kubernetes cluster
2. Connect to GKE Kubernetes cluster
   gcloud container clusters get-credentials gateway-api-playground --region europe-west1 --project conf42-2024

Ingress exercise

First exercise is about use Ingress API to expose in a basic way the "blue" application with some limitations.

1. Basic aim using Ingress API

   +-----------------+          +---------------------+          +------+
   | External Source |    =>    | Load Balancer       |    =>    | blue |
   +-----------------+          +---------------------+          +------+
                                                          100%
                                               
   

2. Install v1-blue version exposed with Ingress API

   helm upgrade -i -f dummy-helm-values-v1.yaml dummy-release-v1-blue dummy-helm -n development --create-namespace
   

3. Wait the GKE Cloud Loadbalancer provisioning on web console and copy the URL

4. Edit /etc/hosts file and reach it

   [publicIP] my-dummy-colored-app-exposed-by-ingress.net
   

   Reach it --> http://my-dummy-colored-app-exposed-by-ingress.net

5. Limitations
   Ex.
   Q: How can I add some http url rewrites or header manipulations?
   A: You can't!

   We already talked in previou slides on how we survived (provider specific ingress controllers).

Gateway API exercise

Let's now see how Gateway API solved a lot of Ingress API limitations (ex. more advanced native http rules, more scalable and role oriented) in a more real scenario.

1. Install v2-green version without any Ingresses

   helm upgrade -i -f dummy-helm-values-v2.yaml dummy-release-v2-green dummy-helm -n development --create-namespace
   

2. Label development namespace

   kubectl label ns development shared-public-gateway-access=true
   

3. Create infrastructure namespace

   k create ns infrastructure
   

4. 🧢 Cluster operator hat -- install Gateway resource Note that GaytewayClass is already provided by the cloud provider (in this case by GKE)

   k apply -f gateway-api-stuff/cluster-operator-hat/gateway.yaml
   

5. Wait the Gateway to be accepted (it takes few seconds)

   Go to "Kubernetes Engine" -> "Gateways, Services & Ingress" -> "Gateways"

6. Let's see the new Load Balancer

   Go to "Cloud Load Balancing"
   Note that no rules created yet

7. 🧢 Developer operator hat -- install HTTPRoute resource

   k apply -f gateway-api-stuff/development-hat/route-easy.yaml
   

8. Wait the rules to be synced

   Go to "Cloud Load Balancing"
   Some rules should come up

9. Retrieve the new cloud load balancer URL, edit /etc/hosts file and reach it

   [publicIP] my-dummy-colored-app-exposed-by-gateway-api.net
   

   Reach it --> http://my-dummy-colored-app-exposed-by-gateway-api.net

10. 🧢 Developer operator hat -- Play with some more complex routes!

    10.a add header to the request

    +-----------------+          +------------------------+          +------+
    | External Source |    =>    | Api Gateway / Balancer |    =>    | blue |
    +-----------------+          +------------------------+          +------+
                                                                100%
                                                                custom-header:<value>             
                                                
    

    k apply -f gateway-api-stuff/development-hat/route-header-rewrite.yaml
    

    10.b path rewrite

    +-----------------+          +------------------------+          +------+
    | External Source |    =>    | Api Gateway / Balancer |    =>    | blue |
    +-----------------+          +------------------------+          +------+
                                                                100%
                                                                custom-header:<value>       
                                                                / --> /custom-path      
                                                
    

    k apply -f gateway-api-stuff/development-hat/route-header-path-rewrite.yaml
    

    10.c canary deploy

    +-----------------+          +------------------------+             +------+
    | External Source |    =>    | Api Gateway / Balancer |    (no)  => | blue |
    +-----------------+          +------------------------+             +------+
                                `traffic:test` header there?       
                                                                        +-------+
                                                               (yes) => | green |
                                                                        +-------+
    
    

    k apply -f gateway-api-stuff/development-hat/route-canary.yaml
    

    10.d blue green deploy

    +-----------------+          +------------------------+             +------+
    | External Source |    =>    | Api Gateway / Balancer |    50%  =>  | blue |
    +-----------------+          +------------------------+             +------+
    
                                                                        +-------+
                                                               50%   => | green |
                                                                        +-------+
    
    

    k apply -f gateway-api-stuff/development-hat/route-blue-green.yaml