Bash script to init a Flask App.

README.md

Flask_init

What does it do?

• Creates a folder called as the argument app_name in the path provided
• Creates a python virtual environment in that path
• Installs Flask in the virtual env
• Creates a boilerplate application
• Creates gitignore
• Creates a bootstrap script that automatically activates the virtual environment and runs the app when executed
• Can also create a requirements.txt file if the parameter --package is passed

Requirements:

• Python3

Installation:

• Download the file to your linux computer (might work for mac)
• Add execute permissions by running chmod +x flask_init.sh

Run app

./flask_init.sh --app_name myApp --path /opt/flask_examples ./flask_init.sh --app_name myApp --path /opt/flask_examples --package

flask_init.sh

#! /bin/bash

# Created by franz

set -o errexit
#set -x

# DEFAULTS
package="false"

# HELPERS
function throw_if_empty() {
    local name="$1"
    local value="$2"
    if [ -z "$value" ]; then
        echo "Parameter '$name' cannot be empty." 1>&2
        printUsage
        exit -1
    fi
}

function checkRequirements() {
    if ! command -v python3 >/dev/null; then
        echo "Error! Could not find python3" 1>&2
        printUsage
        exit -1
    fi
    
}

# FUNCTIONS
function createRequirementFile() {
    pushd "$FULL_PATH"
    source env/bin/activate
    pip freeze > requirements.txt
    deactivate
    popd
}

function createApp(){
    mkdir -p "$FULL_PATH"
    pushd "$FULL_PATH"
    mkdir static templates
    createEnv
    createGitIgnore
    initApp
    createBootstrapScript
    popd
}

function createBootstrapScript() {
    cat <<EOF > bootstrap.sh
#!/bin/bash
export FLASK_APP=./app.py
export FLASK_DEBUG=1
export FLASK_RUN_PORT=8080
source env/bin/activate

flask run
EOF
}

function initApp() {
    cat <<EOF > app.py
from flask import Flask
app = Flask(__name__)
@app.route('/')
def hello_world():
    return "<h1>Hello World</h1>"

#app.run(debug=True)
EOF
}

function createEnv() {
    python3 -m venv env
    source env/bin/activate
    pip install flask
}

function createGitIgnore() {
    cat <<EOF > .gitignore
env
__pycache__
EOF
}

# USAGE
echo $@
function printUsage() {
    cat <<EOF
Will create a flask app boilerplate with a pyenv and Flask installed
It will also create a base app with '/' route and a static and 
templates directories along with gitignore
    
Command
    $0
Requirements:
    * Python 3
    * python3.9-venv (if running on debian based linux)
Arguments:
    --app_name              : Required, Flask folder name
    --path                  : Path where the folder will be created
    --package               : Creates a requirements.txt in the path provided
Example:
    ./"$0" --app_name myApp --path /opt/flask_examples
    ./"$0" --app_name myApp --path /opt/flask_examples --package
EOF
}

while [[ $# >0 ]]
do
    key="$1"
    shift
    case $key in
        --app_name)
        app_name="$1"
        shift
        ;;
        --path)
        app_path="$1"
        shift
        ;;
        --package)
        package="true"
        ;;
        --help|-help|-h)
        printUsage
        exit 13
        ;;
        *)
        echo "Error! Unknown argument '$key to script '$0'" 1>&2
        printUsage
        exit -1
    esac
done

throw_if_empty --app_name "$app_name"
throw_if_empty --path "$app_path"
checkRequirements
FULL_PATH="$app_path"/"$app_name"

if [ "$package" = "true" ]; then
    createRequirementFile
fi

if [ "$package" = "false" ]; then
    createApp
fi