Scripting with gcloud in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

Understanding gcloud command output

You run the command gcloud compute instances list --filter="status=RUNNING" --format="value(name)". What is the output format you will get?

A A JSON array containing objects with instance names as keys.

B A YAML formatted list of instance names with their statuses.

C A table with columns showing instance names and statuses.

D A plain list of instance names, one per line, with no extra formatting.

💡 Hint

The --format="value(name)" flag outputs only the values of the 'name' field.

The --format="value(name)" option tells gcloud to output only the values of the 'name' field as plain text, one per line, without any extra formatting like tables or JSON.

❓ Configuration

intermediate

Correct gcloud command to create a VM with a startup script

Which gcloud command correctly creates a Compute Engine VM named web-server in zone us-central1-a with a startup script located at startup.sh?

A gcloud compute instances create web-server --zone=us-central1-a --metadata-from-file startup-script=startup.sh

B gcloud compute instances create web-server --zone=us-central1-a --startup-script=startup.sh

C gcloud compute instances create web-server --zone=us-central1-a --metadata startup-script=$(cat startup.sh)

D gcloud compute instances create web-server --zone=us-central1-a --metadata startup-script=startup.sh

💡 Hint

The startup script must be passed as a file using the correct metadata flag.

The --metadata-from-file startup-script=startup.sh flag correctly uploads the contents of the startup.sh file as the startup script metadata for the VM.

❓ Architecture

advanced

Automating multi-region deployment with gcloud scripting

You want to write a script that creates a Compute Engine instance named app-server in three different zones: us-east1-b, us-west1-a, and europe-west1-b. Which approach ensures the script runs efficiently and handles errors gracefully?

A Run the three commands in parallel without error checking to save time.

B Run a single <code>gcloud compute instances create</code> command with all three zones specified in one command.

C Run three separate <code>gcloud compute instances create</code> commands sequentially, checking the exit status after each and logging errors.

D Create one instance and then copy it to other zones using <code>gcloud compute instances copy</code>.

💡 Hint

gcloud commands typically create one instance per command; error handling is important in scripts.

Running commands sequentially with error checking ensures each instance is created properly and any failures are logged. Parallel runs without checks risk missing errors. There is no copy command for instances, and you cannot specify multiple zones in one create command.

❓ security

advanced

Securing gcloud scripts with service accounts

You have a gcloud script that creates and deletes resources. To avoid using your personal credentials, which is the best practice to authenticate the script securely?

A Use a service account key file and activate it with <code>gcloud auth activate-service-account --key-file=KEY_FILE</code> before running the script.

B Store your personal gcloud credentials in the script and use <code>gcloud auth login</code> automatically.

C Run the script without authentication; gcloud will prompt for credentials each time.

D Use anonymous authentication to avoid storing any credentials.

💡 Hint

Service accounts provide non-personal credentials for automation.

Activating a service account with a key file allows scripts to run with specific permissions securely without exposing personal credentials. Storing personal credentials or using anonymous authentication is insecure or not possible for resource management.

✅ Best Practice

expert

Optimizing gcloud script for repeated resource creation

You have a gcloud script that creates a Compute Engine instance named test-vm. Running the script multiple times causes errors because the instance already exists. What is the best way to modify the script to avoid errors and ensure idempotent behavior?

A Ignore errors and run the create command every time; errors do not affect the script.

B Use <code>gcloud compute instances describe test-vm</code> to check if the instance exists, and create it only if it does not.

C Add a command to delete the instance before creating it, regardless of its existence.

D Rename the instance each time with a random suffix to avoid name conflicts.

💡 Hint

Idempotent scripts check resource existence before creation.

Checking if the instance exists before creating it prevents errors and makes the script safe to run multiple times. Deleting unconditionally can cause unintended data loss. Ignoring errors or renaming instances is not clean or predictable.