Web task tracker

This is my DevOps pet project: simple web application in containers.

Technologies are combined in this project:

• PostgreSQL
• HTML
• CSS
• JS
• Jinja2
• Flask
• sqlAlchemy
• Docker
• Kubernetes
• Helm

Description

The structure of the project:

task_tracker/
├── .kube/
│   ├── kuber-run.sh
│   ├── app-config.yml
│   ├── app-deployment.yml
│   ├── app-namespace.yml
│   ├── app-service.yml
│   ├── pg-data-pv-pvc.yml
│   ├── pg-deployment.yml
│   └── pg-service.yml
├── helm/
│   ├── templates/
│   │   ├── app-config.yaml
│   │   ├── app-deployment.yaml
│   │   ├── app-namespace.yaml
│   │   ├── app-service.yaml
│   │   ├── pg-data-pv-pvc.yaml
│   │   ├── pg-deployment.yaml
│   │   └── pg-service.yaml
│   ├── Chart.yaml
│   ├── .helmignore
│   └── values.yaml
├── initdb/
│   └── initdb.sh
├── static/
│   ├── css/
│   │   ├── bootstrap.min.css
│   │   └── bootstrap.min.css.map
│   └── js/
│       ├── bootstrap.bundle.min.js
│       └── bootstrap.bundle.min.js.map
├── templates/
│   ├── base.html
│   ├── error.html
│   ├── index.html
│   └── tasks.html
├── .dockerignore
├── .env
├── .gitignore
├── app.py
├── docker-compose.yml
├── Dockerfile
└── requirements.txt

1. Firstly, to save my time learn something new, I took ready-made styles from Bootsrap and templated my static HTML code using Jinja.
2. I wrote a shell script to initialize Postgres environment (database, user and schema).
3. Next, I created a Dockerfile and a docker-compose.yml for eazy execution without any issues. Btw in the docker-compose.yml file, initdb.sh is mounted inside the container.
4. To run this application in k8s cluster locally, there are manifests in .kube/ directory. Also, there is a shell script to apply manifests in the right sequence.
5. Finally, I made a simple Helm chart that you can use to run the task tracker with your own specifications.

So, you have a few different ways to use this project. Check it below...

How to use it?

1. Application only

For using clean flask application you should have this files only (and your database ofc):

task_tracker/
├── static/
│   ├── css/
│   │   ├── bootstrap.min.css
│   │   └── bootstrap.min.css.map
│   └── js/
│       ├── bootstrap.bundle.min.js
│       └── bootstrap.bundle.min.js.map
├── templates/
│   ├── base.html
│   ├── error.html
│   ├── index.html
│   └── tasks.html
├── app.py
└── requirements.txt

1. Create python virtual environment if it doesn't exist:

   python -m venv venv

2. Activate your virtual environment:

   source venv/bin/activate

3. Install all requirements from the file of the same name:

   pip install -r requirements.txt

4. Initialise your Postgres database with parameters specified in .env file (or define your environment variables). Particularly, for my .env you should use this SQL script:

   CREATE DATABASE task_tracker;
   CREATE USER task_tracker_user WITH PASSWORD '123';
   CREATE SCHEMA task_tracker_schema;
   ALTER SCHEMA task_tracker_schema OWNER TO task_tracker_user;
   ALTER DATABASE task_tracker OWNER TO task_tracker_user;

By the way, initdb/initdb.sh can help you if you're on Linux.

2. Application in Docker containers

A: Only application in Docker container

• If you want to use my prepared image from dockerhub, run this:

1. Pull my image from registry

   docker pull blurrysignature/task-tracker-web:v1.0

2. Run container with variables from .env file

   docker run --rm -d \
       --name your_container_name \
       -p 8000:8000 \
       -e HOST=postgres \
       -e PORT=5432 \
       -e PG_DBNAME=task_tracker \
       -e PG_USER=task_tracker_user \
       -e PG_PASSWORD=123 \
       blurrysignature/task-tracker-web:v1.0 

• If you want to run container with custom settings, do this steps:

1. Build image using Dockerfile with your name of the image

   docker build -t your_image_name .

2. Run container with your variables

   docker run --rm -d \
       --name your_container_name \
       -p 8000:8000 \
       -e HOST=postgres \
       -e PORT=5432 \
       -e PG_DBNAME=your_db_name \
       -e PG_USER=your_user \
       -e PG_PASSWORD=your_password \
       your_image_name

B: docker-compose (postgres + application) BEST WAY!

This is all you need to do:

docker-compose up -d

3. Application in Kubernetes cluster

Before starting, change paths to volumes in pg-deployment.yml and pg-data-pv-pvc.yml.

bash kuber-run.sh

4. Helm chart executing

Same thing: change paths to volumes in values.yaml before starting.

helm install name-of-your-release helm/