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Kubernetes hands-on lab for Taiwan Cloud Edge Summit 2019
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README.md

Todo sample for Kubernetes

NOTE: A revised version of this workshop is available at https://github.com/William-Yeh/workshop-gcpug201906

Configurable settings

Store config in the environment (aka the 12-factor app principles).

Public accessible endpoint for todoapi backend, defined in config.local.yml:

  • TODOAPI_HOST : default = localhost
  • TODOAPI_PORT : default = 30080
  • TODOAPI_PATH : default = /api/todo

A version for deployment on the cloud is also provided in config.test.yml:

  • TODOAPI_HOST : external IP (ephemeral or static) or domain name allocated by cloud providers.
  • TODOAPI_PORT : default = 80
  • TODOAPI_PATH : default = /api/todo

Architecture

A dockerized web app with separate frontend and backend services on Kubernetes (both locally and on the cloud).

Frontend

Static HTML5 files and jQuery scripts.

Local web endpoint:

  • host = localhost
  • port = 30000

Cloud web endpoint:

  • host = external IP (ephemeral or static) or domain name allocated by cloud providers
  • port = 80

Backend

Backend program written in ASP.NET Core. Two versions are provided: stable version and canary version.

Local API endpoint:

  • host = localhost
  • port = TODOAPI_PORT (default = 30080)
  • path = TODOAPI_PATH (default = /api/todo)

Cloud API endpoint:

  • host = TODOAPI_HOST (to be revised in config.test.yml), external IP (ephemeral or static) or domain name allocated by cloud providers
  • port = TODOAPI_PORT (default = 80)
  • path = TODOAPI_PATH (default = /api/todo)

Usage

Preparation for environment

  1. If you're using GKE, do the gke-steps first.

  2. Create a todo namespace for this app:

    % kubectl create ns todo
    
  3. Load the ConfigMap content, if the workshop is to be run locally:

    % kubectl apply -f k8s/local/config.local.yml  -n todo
    % kubectl get configmaps  -n todo
    
  4. Load the ConfigMap content, if the workshop is for test on the cloud (GCP/GKE for example):

    # reserve a new static external IP address for backend todoapi
    % gcloud compute addresses create todoapi --region=us-west1 --network-tier=PREMIUM
    
    # make sure the static external IP address has been allocated
    % gcloud compute addresses list
    
    # replace the placeholder string "111.222.333.444" with the allocated IP address
    % vi k8s/test/config.test.yml
    % vi k8s/test/todoapi-service.yml
    
    #...
    
    # now, load it!
    % kubectl apply -f k8s/test/config.test.yml  -n todo
    % kubectl get configmaps  -n todo
    
  5. Fill in correct image names by modifying the PROJECT_ID string in the following files:

Build

  1. Build images:

    % docker-compose build
    

If you're running the workshop on the cloud, be sure to push the images to registry (GCR for example):

% docker push gcr.io/PROJECT_ID/

Run at local stage

  1. Change working directory to k8s/local.

    % cd k8s/local
    
  2. Start the backend:

    % kubectl apply -f todoapi-service.yml -n todo
    % kubectl get svc  -n todo
    
  3. Start the frontend:

    % kubectl apply -f todofrontend-service.yml -n todo
    % kubectl get svc  -n todo
    
  4. Use your browser to visit the web app at http://localhost:30000

Run at test stage

The same as the local stage, except that:

  • Change working directory to k8s/test.

  • Use your browser to visit the web app at http://FRONTEND_EXTERNAL_IP:80

Canary

  1. See the number of pods in the deployment:

    % kubectl get deployments -n todo
    NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
    todoapi   3         3         3            3           4m
    
  2. Launch the canary part of the todoapi service:

    % kubectl apply -f todoapi-canary-deployment.yml -n todo
    
  3. See again the number of pods in the deployments, including the canary part:

    % kubectl get deployments -n todo
    NAME             DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
    todoapi          3         3         3            3           5m
    todoapi-canary   1         1         1            1           44s
    
  4. Scale the canary part:

    % kubectl patch deployment todoapi-canary \
        --patch "$(cat todoapi-canary-patch.yml)" -n todo
    
  5. See again the number of pods in the deployments, including the canary part:

    % kubectl get deployments -n todo
    NAME             DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
    todoapi          3         3         3            3           7m
    todoapi-canary   2         2         2            2           2m
    

Kubernetes dashboard

See here if you'd like to use Kubernetes dashboard locally.

About the source code

The sample was extracted from the TodoApi demo in the Microsoft Docs site, retrieved on Feb 14, 2019:

The original source code to be used in this repo is packed in the TodoApi-original.zip file for your reference.

LICENSE

Apache License 2.0. See the LICENSE file.

History

7.0: Support canary release.

6.0: Support Kubernetes on the cloud (GKE for example).

5.0: Support ConfigMap and naming convention.

4.1: Use Kubernetes dashboard.

4.0: Support Kubernetes (locally).

3.0: Separate frontend and backend into 2 distinct containers.

2.0: Dockerize the app with simple Dockerfile and docker-compose.yml.

1.0: Extracted from Microsoft Docs.

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