Deploy and Manage Applications on Google App Engine

ARC112 — Deploy and Manage Applications on Google App Engine: Challenge Lab

Estimated time: 30 minutes

# 🚀 App Engine: Qwik Start - Challenge Lab > ⚠️ **Disclaimer:** This guide is provided for educational and learning purposes only. It is intended to help you understand Google Cloud App Engine, application deployment, API configuration, regions, application environments, and App Engine services while preparing for Google Cloud certifications and hands-on Challenge Labs. Always follow the official Google Cloud and Google Cloud Skills Boost/Qwiklabs instructions and applicable terms of service.

#!/bin/bash
set +H
clear

# ==============================================================================
# Color Variables & Orbit of Ops Branding
# ==============================================================================
RED='\e[1;31m'
GREEN='\e[1;32m'
YELLOW='\e[1;33m'
BLUE='\e[1;34m'
MAGENTA='\e[1;35m'
CYAN='\e[1;36m'
WHITE='\e[1;37m'
BOLD='\e[1m'
RESET='\e[0m'

echo -e "${CYAN}${BOLD}"
cat << "EOF"
  ____       _     _ _            __    ___            
 / __ \     | |   (_) |          / _|  / _ \           
| |  | |_ __| |__  _| |_   ___  | |_  | | | |_ __  ___ 
| |  | | '__| '_ \| | __| / _ \ |  _| | | | | '_ \/ __|
| |__| | |  | |_) | | |_ | (_) || |   | |_| | |_) \__ \
 \____/|_|  |_.__/|_|\__| \___/ |_|    \___/| .__/|___/
                                            | |        
                                            |_|        
EOF
echo -e "${RESET}"
echo -e "${MAGENTA}${BOLD} 🚀 Starting Orbit of Ops Master Execution (ARC112)... ${RESET}"
echo -e "${BLUE}--------------------------------------------------------------------------------${RESET}\n"

# ==============================================================================
# PRE-FLIGHT CHECKS & VARIABLES (DYNAMIC AUTO-FETCH)
# ==============================================================================
echo -e "${BOLD}${YELLOW}[Orbit of Ops] Auto-fetching Project and Zone...${RESET}"

export PROJECT_ID=$(gcloud config get-value project 2>/dev/null)
if [[ -z "$PROJECT_ID" ]]; then
    export PROJECT_ID=$DEVSHELL_PROJECT_ID
fi

export ZONE=$(gcloud compute instances list --filter="name=lab-setup" --format="value(zone)" --limit=1 2>/dev/null)

if [[ -z "$ZONE" ]]; then
    echo -e "${BOLD}${RED}⚠️ Could not auto-detect the default zone via gcloud metadata.${RESET}"
    echo -ne "${BOLD}${CYAN}Please enter the lab Zone (e.g., us-east1-c): ${RESET}"
    read ZONE
    export ZONE
fi

gcloud config set compute/zone $ZONE 2>/dev/null

echo -e "✅ Project ID: ${GREEN}$PROJECT_ID${RESET}"
echo -e "✅ Zone:       ${GREEN}$ZONE${RESET}\n"
echo -e "${BLUE}--------------------------------------------------------------------------------${RESET}\n"

# ==============================================================================
# USER INPUT
# ==============================================================================
echo -e "${BOLD}${YELLOW}⚠️ ATTENTION: Check your lab instructions for the following values: ${RESET}"

echo -ne "${BOLD}${CYAN}Enter the App Engine Region (from Task 3, e.g., us-central): ${RESET}"
read APP_REGION

echo -e "\n${BLUE}--------------------------------------------------------------------------------${RESET}\n"

# ==============================================================================
# MAIN SCRIPT EXECUTION
# ==============================================================================

echo -e "${BOLD}${CYAN}[Orbit of Ops] Task 1: Enabling the App Engine Admin API...${RESET}"
gcloud services enable appengine.googleapis.com --quiet

echo -e "\n${BOLD}${CYAN}[Orbit of Ops] Task 2: Downloading the Hello World app on VM 'lab-setup'...${RESET}"
gcloud compute ssh lab-setup \
    --zone=$ZONE \
    --quiet \
    --command="git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git"

echo -e "\n${BOLD}${CYAN}[Orbit of Ops] Task 3: Cloning repository locally and configuring scaling limits...${RESET}"
git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git
cd python-docs-samples/appengine/standard_python3/hello_world

# Hardcode instance limits using printf to avoid copy-paste whitespace errors
printf "\nautomatic_scaling:\n  max_instances: 1\n" >> app.yaml

gcloud app create --region=$APP_REGION --quiet

echo -e "\n${BOLD}${CYAN}[Orbit of Ops] Task 3: Deploying the initial application (Takes ~2 minutes)...${RESET}"
gcloud app deploy --quiet

echo -e "\n${BOLD}${CYAN}[Orbit of Ops] Task 4: Updating the application code with 'Hello, Cruel World!'...${RESET}"
sed -i "s/return.*/return 'Hello, Cruel World!'/g" main.py

echo -e "\n${BOLD}${CYAN}[Orbit of Ops] Task 4: Redeploying the updated application over the existing version...${RESET}"
# Fetch the ID of the version we just created to overwrite it and bypass the 10-instance quota
CURRENT_VERSION=$(gcloud app versions list --hide-no-traffic --format="value(version.id)" | head -n 1)

# Deploy directly over the existing version
gcloud app deploy --version=$CURRENT_VERSION --quiet

# ==============================================================================
# COMPLETION
# ==============================================================================
echo -e "\n${MAGENTA}${BOLD}╔════════════════════════════════════════════════════════════╗${RESET}"
echo -e "${MAGENTA}${BOLD}║            🎉 AUTOMATION COMPLETED SUCCESSFULLY 🎉           ║${RESET}"
echo -e "${MAGENTA}${BOLD}╚════════════════════════════════════════════════════════════╝${RESET}"
echo -e "${GREEN}${BOLD}You can now safely click ALL 'Check my progress' buttons in your lab manual.${RESET}"
echo -e "${CYAN}${BOLD}Subscribe to Orbit of Ops: https://www.youtube.com/@orbitofops/videos${RESET}\n"