gmykhailiuta / bgapp

Blue-Green Deployment on MiniKube and Docker-Compose

Introduction

This repository contains a proof-of-concept of blue-green deployment af an application to Minikube and Docker-compose. sk script in the root stands for "Swiss Knife" is inspired by make(file) and contains all commands necessary to manage code and deployment.

Requirements (tested versions)

1. Linux (Arch)
2. VirtualBox 6.1.28 r147628
3. Minikube v1.24.0
4. Kubernetes / kubectl v1.22.4
5. Docker 20.10.10
6. Python3 3.9.7
7. Jq 1.6

Development

Developing and running locally

1. Initialize environment:

    ./sk init-venv
   

2. Run locally:

    ./sk run-dev
    # or
    ./sk run-gunicorn
   

3. Build docker image:

    ./sk build
   

4. Run in docker:

    ./sk run-docker
   

5. Run tests (infrastructure ones, in Docker):

    ./sk test-docker
   

Deployment to Minikube

Setup environment

1. Start minikube. For instance:

    minikube start --kubernetes-version v1.22.4 --vm-driver=virtualbox
   
    #or 
   
    ./sk mk-init
   

2. Switch to minikube's docker:

    minikube docker-env | source
   

Build and release

4. Build few docker images' versions:

    VERSION=0.0.1 ./sk build
    # change the code
    VERSION=0.0.2 ./sk build
   

5. Deploy

    VERSION=0.0.1 ./sk mk-deploy-all
    VERSION=0.0.2 ROLE=green ./sk mk-deploy-deployment
    ./sk mk-get-public-url
   

6. Start continuous role switching:

    ./sk mk-role-blink
   

7. Run benchmark testing (in separate console):

    ./sk mk-test-ab
   

Deployment to Docker-Compose

Possible and tested, but is out of scope.

Conclusion

This solution is over-simplified and could work only as PoC. Real application production usage would require an infrastructure management code (Terraform, etc.), package manager for Kubernetes (e.g. Helm), code tests, fully-featured ingress-controller and many other important features.

Nevertheless, it was possible to achieve seamless switching between blue and green environments both with Minikube and Docker-compose setups (i.e. get zero failed requests in Apache Benchmark report):

    ...
    Server Software:        gunicorn
    Server Hostname:        192.168.59.108
    Server Port:            30998

    Document Path:          /api/
    Document Length:        20 bytes

    Concurrency Level:      1
    Time taken for tests:   18.867 seconds
    Complete requests:      9999
    Failed requests:        0
    Total transferred:      1649835 bytes
    HTML transferred:       199980 bytes
    Requests per second:    529.98 [#/sec] (mean)
    Time per request:       1.887 [ms] (mean)
    Time per request:       1.887 [ms] (mean, across all concurrent requests)
    Transfer rate:          85.40 [Kbytes/sec] received
    ...