Headless deployment setup in Raspberry Pi - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Raspberry Pi headless Wi-Fi setup script?

Consider this script snippet that configures Wi-Fi on a Raspberry Pi without a monitor. What will be the output after running it?

Raspberry Pi

import os
ssid = "HomeNetwork"
password = "mypassword"
wpa_supplicant_conf = f"""
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={{
    ssid=\"{ssid}\"
    psk=\"{password}\"
    key_mgmt=WPA-PSK
}}
"""

with open("/etc/wpa_supplicant/wpa_supplicant.conf", "w") as f:
    f.write(wpa_supplicant_conf)

print("Wi-Fi configuration file created.")

A Wi-Fi configuration file created.

B Permission denied error

C File not found error

D Syntax error in configuration file

💡 Hint

Think about file writing permissions on Raspberry Pi OS.

The script writes the Wi-Fi config file with correct syntax and prints the success message. If run with proper permissions, it succeeds.

🧠 Conceptual

intermediate

Which file enables SSH access on a Raspberry Pi in headless mode?

When preparing a Raspberry Pi SD card for headless setup, which file must be created or modified to enable SSH access on boot?

A wpa_supplicant.conf

B ssh (empty file in boot partition)

C cmdline.txt

D config.txt

💡 Hint

This file is placed in the boot partition and has no extension.

Creating an empty file named 'ssh' in the boot partition enables SSH on first boot.

🔧 Debug

advanced

Why does this headless Wi-Fi setup script fail to connect?

This Python script writes a wpa_supplicant.conf file but the Raspberry Pi does not connect to Wi-Fi. Identify the bug.

Raspberry Pi

ssid = "MyWiFi"
password = "pass1234"
wpa_conf = f"""
network={{
ssid="{ssid}"
psk="{password}"
key_mgmt=WPA-PSK
}}
"""
with open("/etc/wpa_supplicant/wpa_supplicant.conf", "w") as f:
    f.write(wpa_conf)
print("Config written")

A ssid and psk lines lack indentation

B Double quotes inside f-string cause syntax error

C Missing country code line in config

D File path is incorrect

💡 Hint

Check the indentation inside the network block.

Wi-Fi config requires ssid and psk lines to be indented inside network block for wpa_supplicant to parse correctly.

📝 Syntax

advanced

What error does this Raspberry Pi headless setup script produce?

What error will this Python code produce when run on Raspberry Pi to create wpa_supplicant.conf?

Raspberry Pi

with open('/etc/wpa_supplicant/wpa_supplicant.conf', 'w') as f
    f.write('network={ssid="MyWiFi" psk="pass1234"}')

A IndentationError: expected an indented block

B FileNotFoundError: no such file or directory

C PermissionError: [Errno 13] Permission denied

D SyntaxError: expected ':' after 'with' statement

💡 Hint

Check the syntax of the with statement.

The with statement is missing a colon at the end, causing a SyntaxError.

🚀 Application

expert

How many lines will the Raspberry Pi read from wpa_supplicant.conf after this script runs?

This script writes a wpa_supplicant.conf file for headless Wi-Fi setup. How many lines will the file contain?

Raspberry Pi

conf = '''ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=GB

network={
    ssid="OfficeWiFi"
    psk="securepass"
    key_mgmt=WPA-PSK
}
'''
with open('/etc/wpa_supplicant/wpa_supplicant.conf', 'w') as file:
    file.write(conf)

A 8

B 10

C 9

D 7

💡 Hint

Count all lines including blank lines in the triple-quoted string.

The string has 9 lines including blank lines and closing braces.