Overview

This sample demonstrates how to build and deploy an ASP.NET Core-based microservice as an extension leveraging the minimal web API functionality and exposing the API in SAP BTP, Kyma runtime.

You can find the application code in the TodoApi directory.

This sample demonstrates how to:

• Create a development Namespace in the Kyma runtime.
• Create and deploy an ASP.NET Core-based application in the Kyma runtime.
• Expose the ASP.NET Core application using APIRules.
• Call the API.

ToDo App

The application used in this sample is described here

Prerequisites

This tutorial requires the following prerequisites:

• Docker
• Kubernetes
• .NET
• REST Client Extension
• Build Tooling

Steps

Prepare for deployment

• Create a new dotnetdev Namespace:

kubectl create namespace dotnetdev
kubectl label namespaces dotnetdev istio-injection=enabled

• Adjust the placeholder DOCKER_ACCOUNT in the Makefile and then build and push the image to the Docker repository:

DOCKER_ACCOUNT={your-docker-account} make build-and-push-image

• Update the image name in the Kubernetes Deployment. Refer to the standard Kubernetes Deployment and Service definitions.

Kubernetes Deployment

This section details out deploying the extension using standard Kubernetes resources.

To deploy as Helm chart, please refer to Helm Chart Deployment

• Deploy the application:

kubectl -n dotnetdev apply -f ./k8s/deployment.yaml

• Verify that the Pods are up and running:

kubectl -n dotnetdev get po -l app=sample-extension-dotnet-minimalapi

The expected result shows that the Pod for the sample-extension-dotnet Deployment is running:

kubectl -n dotnetdev get po -l app=sample-extension-dotnet-minimalapi
NAME                                                  READY   STATUS    RESTARTS   AGE
sample-extension-dotnet-minimalapi-774fbc5c7b-x44pd   2/2     Running   0          15s

Expose the API

1. Create an APIRule. In the APIRule, specify the Kubernetes Service that is exposed:

apiVersion: gateway.kyma-project.io/v2
kind: APIRule
metadata:
  name: sample-extension-dotnet-minimalapi
spec:
  gateway: kyma-system/kyma-gateway
  hosts:
  - sample-extension-dotnet-minimalapi
  rules:
    - noAuth: true
      methods:
        - GET
        - POST
        - PUT
        - DELETE
      path: /*
  service:
    name: sample-extension-dotnet-minimalapi
    port: 5046

This sample snippet exposes the sample-extension-dotnet-minimalapi Service. The Service is specified in the spec.service.name field. The sample-extension-dotnet-minimalapi subdomain is specified in the spec.service.host field.

• Apply the APIRule:

kubectl -n dotnetdev apply -f ./k8s/api-rule.yaml

Helm Chart Deployment

A Helm Chart definition is also available for developers to try out.

Prerequisites

The following prerequisites are needed:

• Docker
• Kubernetes

Helm install

To install the helm chart in dotnetdev namespace, run the following command. Change the placeholder <YOUR DOCKER ACCOUNT> to use your account.

helm install kymaapp ../helm-charts/sample-extension-dotnet-minimalapi --set image.repository=<YOUR DOCKER ACCOUNT>/dotnet6minimalapi:0.0.1 -n dotnetdev

To verify, the installed chart, run

helm -n dotnetdev ls

This should give you an output like

NAME            NAMESPACE       REVISION        UPDATED                                 STATUS          CHART                           APP VERSION
dev-gateway     dev             1               2020-09-14 17:34:58.607853163 +0000 UTC deployed        gateway-0.0.1
kymaapp         dev             1               2020-09-15 15:18:34.502591 +0200 CEST   deployed        sample-extension-dotnet-0.1.0   1.16.0

Try it out

Access the APIs through this URL:

https://sample-extension-dotnet-minimalapi.{cluster domain}

See several sample calls in the file samplerequests.http. Put the right name for the hostname into the file and execute the different commands to interact with your todo list.