Minimal Viable Continuous delivery (CD)

Have you ever wanted to learn Devops, asked "What is Devops" or wanted to start learning DevOps?

This is a minimal viable example of many of the concepts in DevOps which might help you continue to uncover better ways of doing it and help others learn too.

Explore this repo, ask questions and learn

This is a minimal web application with state (database) which:

✔️ Automatically generates releases based on semantic version for every merge into the main branch (using intuit/auto)
🗄️ Database migrations are version controlled and ran upon app startup
- This repository uses alembic (python) but you might use alembic/doctrine (php), flyway/liquibase (java) - the concept is the same
🔎 When a pull request is opened, a preview application is automatically built, with a url so people can view the proposed new version
🔃 When a pull request gets merged into the main branch, the latest application is automatically deployed (using Dokku). (Pipeline Code / UI)
- You might use Kubernetes with ArgoCD (the underlying concepts are the same)
💾 A backup/snapshot of any database is taken pre and post each release
🚨 Codebase is regularly automatically scanned for known security issues
☸️ At each release a container is built and published to a container registry (Pipeline Code / UI)

Local Development

cd src
python3.9 -m venv venv
. venv/bin/activate
pip install -r requirements.txt

Env settings:

cp .env.example .env

Run locally

cd src
. venv/bin/activate
export FLASK_APP=minimalcd
export FLASK_DEBUG=1
flask run

http://127.0.0.1:5000

Build

podman build -t minimalcd -f src/Dockerfile

Run

podman run -p 8082:80 minimalcd

Day0

(almost) Everything below this point are instructions if you wanted to set this up yourself from scratch

Dokku

APP_NAME=<app-name>
DOKKU_SERVER_IP=<dokku-server-ip>
DOKKU_USERNAME=<username>
git remote add dokku $DOKKU_USERNAME@$DOKKU_SERVER_IP:$APP_NAME
git remote -v show
ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku apps:create $APP_NAME
ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku git:initialize $APP_NAME
ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku builder:set minimalcd build-dir src
git push dokku main

Example:

APP_NAME=minimalcd
DOKKU_SERVER_IP=192.168.1.10
DOKKU_USERNAME=dokku
git remote add dokku $DOKKU_USERNAME@$DOKKU_SERVER_IP:$APP_NAME
git remote -v show
ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku apps:create $APP_NAME
ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku git:initialize $APP_NAME
ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku builder-dockerfile:set $APP_NAME dockerfile-path src/Dockerfile
git push dokku main

Auto release using autoc

curl -L https://github.com/intuit/auto/releases/download/v10.36.5/auto-linux.gz > auto-linux.gz
gunzip auto-linux.gz
chmod +x auto-linux
./auto-linux init
# follow on-screen
./auto-linux create-labels

Destroy / Teardown everything

ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku apps:destroy --force $APP_NAME

Troubleshooting

Dokku by default expects your Dockerfile to be in the root directory, and the default working directory is the root of the repo.

For changing the name/location of the Dockerfile, you can use the builder-dockerfile:set:

ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku builder-dockerfile:set $APP_NAME dockerfile-path Dockerfile

For changing the working directory of the docker build context, use:

ssh $DOKKU_USERNAME@$DOKKU_SERVER_IP -C dokku builder:set minimalcd build-dir src

See dokku/dokku#4502 for more details.

Container Hosting Service

Container hosting service is a (you guessed it!) container hosting service, which automates all the automation above for your own pet projects 🚀

Checkout Container Hosting Service

KarmaComputing/minimalcd