Example of building on demand for a project in Go

build-on-demand.sh

#!/usr/bin/env bash

function killpidfile {
    echo "Killing process"
    if [ -f ".debug.pid" ]; then
        kill -15 $(cat .debug.pid)
    fi
}

function build {
    echo "Rebuilding app"
    source $UBI_ENV_CONFIG_DEBUG
    echo "================ BUILDING ================" >> .debug.log
    make debug >> .debug.log 2>&1
}

function run {
    echo "Starting service"
    echo "================ RESTART ================" >> .debug.log
    nohup bin/debug/ubiserver >> .debug.log 2>&1 &
    echo $! > .debug.pid
}

# Check debug variables
# if [ -z $UBI_ENV_CONFIG_DEBUG ]; then
#    echo "No UBI_ENV_CONFIG_DEBUG variable defined"
#    exit
#fi

# Check if process already exists
if [ -f ".debug.pid" ]; then
    PID=$(cat .debug.pid)

    if !kill -0 $PID 2>/dev/null; then
        kill -15 $PID
    fi
    rm .debug.pid
fi

# Build & run before entering the inotifywait cycle
build && run

# Restart everytime someone do changes
while true; do
    inotifywait -e close_write,moved_to,create -r . |
    while read -r directory events filename; do
        echo "Changes on $filename"
        ext=${filename##*.}

        if [ $ext = 'go' ]
        then
            killpidfile
            build && run
            echo "Ready"
            break
        else
            echo "Not a go file, ignoring"
        fi
    done;
done