Current architecture includes 4 major components. Two of the are daemons:

PostgreSQL 9.5
VotingApp

Two of them are functions containers:

denismakogon/vote-task
denismakogon/result-task

When user votes (sends HTTP Post) VoteApp HTTP route handler triggers asynchronous voting function, this function saves user's vote to persistent storage - PostgreSQL.

Once user wants to retrieve get voting results (sends HTTP Get) VoteApp HTTP route handler triggers synchronous resulting function to retrieve voting statistics.

You can build your own images from given functions, but you are feel free to use pre-built and uploaded to DockerHub images:

denismakogon/vote-task
denismakogon/result-task

Personally recommend to use this PG image because it has 1M+ pulls. Use following commands to start PG container:

docker pull sameersbn/postgresql:latest
docker run --name postgresql -d -p 0.0.0.0:5432:5432 --env-file voteapp/voteapp.env sameersbn/postgresql:latest

VoteApp depends on big set of parameters like:

API host
API port
PostgreSQL host
PostgreSQL user/password
PostgreSQL database

Not all of them are mandatory, almost all parameter can be applied as operating system environment variables:

VOTEAPP_HOST stands for --host
VOTEAPP_POST stands for --port
PG_HOST stands for --pg-host
DB_USER stands for --pg-username
DB_PASS stands for --pg-password
DB_NAME stands for --pg-db
APP_NAME stands for --app-name

Not all of them are defined with default values, that is why there are only several of them are required, for our particular case:

VOTEAPP_HOST
VOTEAPP_PORT

are not required because they were defined with default values.

VoteApp is identified by single Python module app.py that is CLI tool to start a web service:

Usage: app.py [OPTIONS]

Options:
  --host TEXT             API service host.
  --port INTEGER          API service port.
  --pg-host TEXT          PostgreSQL connection host.
  --pg-username TEXT      VoteApp PostgreSQL user.
  --pg-password TEXT      VoteApp PostgreSQL user password.
  --pg-db TEXT            VoteApp PostgreSQL connection.
  --app-name TEXT         Existing Picasso app name
  --help                  Show this message and exit.

In order to simplify VoteApp usage, i recommend to build a container from it, corresponding Dockerfile included. Also there's a file - voteapp.env, you should be aware that it's a sample file, because it is required to adjust a lot parameters there like:

VoteApp daemon configuration
PosgreSQL configuration

Once env file is ready use following command to build a container:

docker build -t voteapp .

To start a container:

docker run --name voteapp -d -p 0.0.0.0:11111:9999 --env-file voteapp.env voteapp

Or you can use pre-built container:

denismakogon/voteapp

To pull container:

docker pull denismakogon/voteapp

To start container:

docker run --name voteapp -d -p 0.0.0.0:11111:9999 --env-file voteapp.env denismakogon/voteapp