Environment variables and configuration in Azure - Step-by-Step Execution

Process Flow - Environment variables and configuration

Start Application

↓

Load Environment Variables

↓

Apply Configuration Settings

↓

Run Application with Config

↓

Use Config Values in Code

↓

End

The application starts by loading environment variables, applies configuration settings, then runs using those values.

Execution Sample

Azure

az webapp config appsettings set --name MyApp --resource-group MyGroup --settings API_KEY=12345

This command sets an environment variable named API_KEY with value 12345 for an Azure Web App.

Process Table

Step	Action	Environment Variable Loaded	Configuration Applied	Effect on Application
1	Start Application	None	None	Application starts without config
2	Load environment variables	API_KEY=12345	None	Variables ready to use
3	Apply configuration	API_KEY=12345	API_KEY=12345	App config updated
4	Run application	API_KEY=12345	API_KEY=12345	App uses API_KEY in code
5	End	API_KEY=12345	API_KEY=12345	Application runs with config

💡 Application runs using environment variables set in configuration

Status Tracker

Variable	Start	After Load	After Apply	Final
API_KEY	None	12345	12345	12345

Key Moments - 2 Insights

Why does the application not see the environment variable if it is set after the app starts?

Because environment variables are loaded at app start (see execution_table step 2). Setting variables after start requires app restart to load them.

Can environment variables be changed while the app is running?

No, changes require reloading or restarting the app to apply new environment variables (refer to variable_tracker showing values fixed after load).

Visual Quiz - 3 Questions

Look at the execution table, at which step are environment variables first available to the application?

A Step 2

B Step 1

C Step 3

D Step 4

💡 Hint

Check the 'Environment Variable Loaded' column in execution_table rows

According to variable_tracker, what is the value of API_KEY after applying configuration?

A None

B Unset

C 12345

D Empty String

💡 Hint

Look at the 'After Apply' column for API_KEY in variable_tracker

If the environment variable API_KEY is changed after step 4 without restarting, what happens?

A Application uses new value immediately

B Application continues using old value

C Application crashes

D Application ignores environment variables

💡 Hint

Refer to key_moments about when environment variables are loaded and used

Concept Snapshot

Environment variables store config outside code.
Set them before app starts.
Azure CLI: az webapp config appsettings set.
App reads variables at start.
Changes need app restart to apply.
Use for secrets and settings.

Full Transcript

This visual execution shows how environment variables and configuration work in Azure. The app starts without config, then loads environment variables like API_KEY. These variables are applied as configuration settings. The app then runs using these values. Variables must be set before app start to be effective. Changing variables after start requires restarting the app. This ensures the app uses the correct configuration securely and reliably.