Service accounts for applications in GCP - Mini Project: Build & Apply

Service accounts for applications

📖 Scenario: You are setting up a Google Cloud Platform (GCP) project where an application needs to access cloud resources securely. To do this, you will create a service account that the application can use to authenticate and get permissions.

🎯 Goal: Create a service account in GCP, assign it a role, and configure the application to use this service account for authentication.

📋 What You'll Learn

Create a service account named app-service-account in the project my-gcp-project

Assign the roles/storage.objectViewer role to the service account

Generate a key file for the service account

Configure the application to use the service account key file for authentication

💡 Why This Matters

🌍 Real World

Service accounts allow applications to securely access cloud resources without user intervention, essential for automation and backend services.

💼 Career

Understanding service accounts is critical for cloud engineers and developers to manage permissions and secure application access in cloud environments.

1

Create the service account

Use the gcloud command to create a service account named app-service-account in the project my-gcp-project. Write the exact command starting with gcloud iam service-accounts create app-service-account and include the --project my-gcp-project flag.

GCP

# Your command here

Hint

Use the gcloud iam service-accounts create command with the service account name and project flag.

2

Assign the storage object viewer role

Assign the role roles/storage.objectViewer to the service account [e-mail] using the gcloud projects add-iam-policy-binding command. Include the --member and --role flags and specify the project my-gcp-project.

GCP

gcloud iam service-accounts create app-service-account --project my-gcp-project
# Your command here

Hint

Use gcloud projects add-iam-policy-binding with the correct member and role flags.

3

Generate a key file for the service account

Generate a JSON key file for the service account [e-mail] using the gcloud iam service-accounts keys create command. Save the key file as app-service-account-key.json.

GCP

gcloud iam service-accounts create app-service-account --project my-gcp-project
gcloud projects add-iam-policy-binding my-gcp-project --member=serviceAccount:[e-mail] --role=roles/storage.objectViewer
# Your command here

Hint

Use gcloud iam service-accounts keys create with the --iam-account flag and specify the output file.

4

Configure the application to use the service account key

Set the environment variable GOOGLE_APPLICATION_CREDENTIALS to the path of the key file app-service-account-key.json so the application can authenticate using the service account. Write the exact command for a Linux shell using export.

GCP

gcloud iam service-accounts create app-service-account --project my-gcp-project
gcloud projects add-iam-policy-binding my-gcp-project --member=serviceAccount:[e-mail] --role=roles/storage.objectViewer
gcloud iam service-accounts keys create app-service-account-key.json --iam-account=[e-mail]
# Your command here

Hint

Use export GOOGLE_APPLICATION_CREDENTIALS="path/to/keyfile.json" to set the environment variable.

Practice

1. What is the main purpose of a service account in Google Cloud Platform (GCP)?

easy

A. To allow applications to authenticate and access GCP resources securely

B. To create user accounts for people to log in to GCP Console

C. To store data in Google Cloud Storage buckets

D. To monitor network traffic between virtual machines

Solution

1. Step 1: Understand service account role

   A service account is a special account used by applications or virtual machines to authenticate and access Google Cloud resources securely without user intervention.

2. Step 2: Differentiate from user accounts

   User accounts are for people to log in, while service accounts are for applications or services to act on behalf of users or themselves.

3. Final Answer:

   To allow applications to authenticate and access GCP resources securely -> Option A

4. Quick Check:

   Service account = app authentication [OK]

Hint: Service accounts are for apps, not people [OK]

Common Mistakes:

• Confusing service accounts with user accounts
• Thinking service accounts store data
• Assuming service accounts monitor network

2. Which of the following is the correct way to assign a service account to a Compute Engine VM instance during creation?

easy

A. Use the --service-account flag with gcloud compute instances create

B. Add the service account email to the VM's firewall rules

C. Specify the service account in the VM's startup script

D. Create a user account with the same name as the service account

Solution

1. Step 1: Identify how to assign service accounts to VMs

   The gcloud compute instances create command supports a --service-account flag to specify which service account the VM should use.

2. Step 2: Eliminate incorrect options

   Firewall rules do not assign service accounts, startup scripts do not assign service accounts, and user accounts are unrelated to service account assignment.

3. Final Answer:

   Use the --service-account flag with gcloud compute instances create -> Option A

4. Quick Check:

   Assign service account with --service-account flag [OK]

Hint: Use --service-account flag when creating VM [OK]

Common Mistakes:

• Trying to assign service account via firewall
• Using startup scripts to assign service accounts
• Confusing user accounts with service accounts

3. Consider this Python code snippet using Google Cloud client libraries:

from google.cloud import storage

client = storage.Client()
buckets = list(client.list_buckets())
print(len(buckets))

What must be true for this code to successfully list buckets?

medium

A. The user must be logged in to GCP Console in a browser

B. The environment must have a service account with Storage Viewer role configured

C. The code must run on a VM with no service account assigned

D. No authentication is needed to list buckets

Solution

1. Step 1: Understand authentication requirement

   Google Cloud client libraries require authentication, usually via a service account or user credentials, to access resources like buckets.

2. Step 2: Identify required permissions

   To list buckets, the service account or user must have at least the Storage Viewer role to read bucket metadata.

3. Final Answer:

   The environment must have a service account with Storage Viewer role configured -> Option B

4. Quick Check:

   Service account with Storage Viewer role needed [OK]

Hint: List buckets needs Storage Viewer role on service account [OK]

Common Mistakes:

• Assuming user login in browser is enough
• Running code without any service account
• Thinking no auth is needed for bucket listing

4. You deployed an application on a GCP VM with a service account, but it fails to access Cloud Storage buckets. What is the most likely cause?

medium

A. The service account email is not the same as the VM name

B. The VM does not have an external IP address

C. The application code is missing the Cloud Storage client library import

D. The service account lacks the necessary IAM permissions for Cloud Storage

Solution

1. Step 1: Check service account permissions

   If the application cannot access Cloud Storage, the most common reason is missing IAM permissions on the service account assigned to the VM.

2. Step 2: Rule out other causes

   Lack of external IP does not block access if using private Google access; missing import causes code errors but not permission failures; service account email unrelated to VM name.

3. Final Answer:

   The service account lacks the necessary IAM permissions for Cloud Storage -> Option D

4. Quick Check:

   Missing IAM permissions cause access failure [OK]

Hint: Check IAM roles on service account first [OK]

Common Mistakes:

• Assuming external IP is required for access
• Blaming code imports without error evidence
• Confusing service account email with VM name

5. You want to deploy a serverless application on Cloud Run that accesses a Cloud SQL database securely. Which approach correctly uses a service account to grant least privilege access?

hard

A. Assign the Cloud Run service account the Storage Admin role to access Cloud SQL

B. Use the default Compute Engine service account with Owner role for Cloud Run

C. Create a service account with only Cloud SQL Client role and assign it to the Cloud Run service

D. Create a user account with Cloud SQL Admin role and embed its credentials in the app

Solution

1. Step 1: Identify least privilege principle

   Grant only the permissions needed. For Cloud SQL access, the Cloud SQL Client role is sufficient.

2. Step 2: Assign correct service account to Cloud Run

   Create a dedicated service account with Cloud SQL Client role and assign it to the Cloud Run service to avoid over-permission.

3. Step 3: Eliminate insecure or excessive options

   Using default service account with Owner role is too broad; Storage Admin role is unrelated; embedding user credentials is insecure.

4. Final Answer:

   Create a service account with only Cloud SQL Client role and assign it to the Cloud Run service -> Option C

5. Quick Check:

   Least privilege: Cloud SQL Client role on service account [OK]

Hint: Use least privilege role on dedicated service account [OK]

Common Mistakes:

• Using overly broad Owner role
• Assigning unrelated roles like Storage Admin
• Embedding user credentials in app code