GSP1306

Overview

Secrets, like passwords and API keys, are sensitive information that should be stored in a secure, encrypted storage which is access-controlled and auditable. On Google Cloud, you can use Secret Manager, a managed service, to securely store the secrets and control access to individual secrets using IAM.

In Spring Boot, you can use Spring Cloud GCP to easily access these secrets by referring to them as any other Spring properties.

In this lab, you store a secret in Secret Manager, build a Spring Boot app that retrieves and displays the secret, and deploy that app to Cloud Run.

What you'll learn

In this lab, you learn how to:

• Create a Spring Boot Java application.
• Configure Secret Manager and create a secret.
• Retrieve a secret from Secret Manager in a Spring Boot app.
• Deploy a Spring Boot app to Cloud Run.

Setup and requirements

Before you click the Start Lab button

Read these instructions. Labs are timed and you cannot pause them. The timer, which starts when you click Start Lab, shows how long Google Cloud resources are made available to you.

This hands-on lab lets you do the lab activities in a real cloud environment, not in a simulation or demo environment. It does so by giving you new, temporary credentials you use to sign in and access Google Cloud for the duration of the lab.

To complete this lab, you need:

• Access to a standard internet browser (Chrome browser recommended).

Note: Use an Incognito (recommended) or private browser window to run this lab. This prevents conflicts between your personal account and the student account, which may cause extra charges incurred to your personal account.

• Time to complete the lab—remember, once you start, you cannot pause a lab.

Note: Use only the student account for this lab. If you use a different Google Cloud account, you may incur charges to that account.

How to start your lab and sign in to the Google Cloud console

1. Click the Start Lab button. If you need to pay for the lab, a dialog opens for you to select your payment method. On the left is the Lab Details pane with the following:

   • The Open Google Cloud console button
   • Time remaining
   • The temporary credentials that you must use for this lab
   • Other information, if needed, to step through this lab

2. Click Open Google Cloud console (or right-click and select Open Link in Incognito Window if you are running the Chrome browser).

   The lab spins up resources, and then opens another tab that shows the Sign in page.

   Tip: Arrange the tabs in separate windows, side-by-side.

   Note: If you see the Choose an account dialog, click Use Another Account.

3. If necessary, copy the Username below and paste it into the Sign in dialog.

   {{{user_0.username | "Username"}}}

   You can also find the Username in the Lab Details pane.

4. Click Next.

5. Copy the Password below and paste it into the Welcome dialog.

   {{{user_0.password | "Password"}}}

   You can also find the Password in the Lab Details pane.

6. Click Next.

   Important: You must use the credentials the lab provides you. Do not use your Google Cloud account credentials. Note: Using your own Google Cloud account for this lab may incur extra charges.

7. Click through the subsequent pages:

   • Accept the terms and conditions.
   • Do not add recovery options or two-factor authentication (because this is a temporary account).
   • Do not sign up for free trials.

After a few moments, the Google Cloud console opens in this tab.

Note: To access Google Cloud products and services, click the Navigation menu or type the service or product name in the Search field.

Activate Cloud Shell

Cloud Shell is a virtual machine that is loaded with development tools. It offers a persistent 5GB home directory and runs on the Google Cloud. Cloud Shell provides command-line access to your Google Cloud resources.

1. Click Activate Cloud Shell at the top of the Google Cloud console.

2. Click through the following windows:

   • Continue through the Cloud Shell information window.
   • Authorize Cloud Shell to use your credentials to make Google Cloud API calls.

When you are connected, you are already authenticated, and the project is set to your Project_ID, . The output contains a line that declares the Project_ID for this session:

Your Cloud Platform project in this session is set to {{{project_0.project_id | "PROJECT_ID"}}}

gcloud is the command-line tool for Google Cloud. It comes pre-installed on Cloud Shell and supports tab-completion.

3. (Optional) You can list the active account name with this command:

gcloud auth list

4. Click Authorize.

Output:

ACTIVE: * ACCOUNT: {{{user_0.username | "ACCOUNT"}}} To set the active account, run: $ gcloud config set account `ACCOUNT`

5. (Optional) You can list the project ID with this command:

gcloud config list project

Output:

[core] project = {{{project_0.project_id | "PROJECT_ID"}}} Note: For full documentation of gcloud, in Google Cloud, refer to the gcloud CLI overview guide.

Task 1. Create a new Spring Boot REST service

Spring Boot simplifies the creation of self-contained, production-ready Spring applications, ready to run without extensive configuration.

Spring Initializr provides a straightforward path for creating a Spring Boot application. You can use curl to create the application by sending a curl request to the Spring Initializr service.

In this task, you use the command line to generate a new Spring Boot application.

Call the Spring Initializr service

• In Cloud Shell, run the following command:

  cd ~ curl https://start.spring.io/starter.zip \ -d type=maven-project \ -d packaging=jar \ -d bootVersion=3.3.5 \ -d dependencies=web,cloud-gcp \ -d javaVersion=21 \ -d name=HelloSecretManager \ -d artifactId=HelloSecretManager \ -o ~/hello-secret-manager.zip \ && unzip -o -d hello-secret-manager ~/hello-secret-manager.zip \ && cd hello-secret-manager

  This command downloads a Spring Boot project configuration from Spring Initializr, saves it as a zip file, unpacks it into a subdirectory, and then changes the current directory to the subdirectory.

  • curl https://start.spring.io/starter.zip : Fetch a Spring Boot project archive in ZIP format from the Spring Initializr service.
  • -d type=maven-project : This specifies that the generated project should use Maven as its build system.
  • -d packaging=jar : This indicates that the application should be packaged as a JAR file.
  • -d bootVersion=3.3.5 : This sets the Spring Boot version to 3.3.5.
  • -d dependencies=web,cloud-gcp : This defines the project's dependencies. web includes Spring Web support for creating web applications, and cloud-gcp adds the necessary dependencies for interacting with Google Cloud Platform services.
  • -d javaVersion=21 : This specifies that the project should use Java version 21.
  • -d name=HelloSecretManager : This sets the project name to "HelloSecretManager".
  • -d artifactId=HelloSecretManager : This sets the Maven artifact ID to "HelloSecretManager".
  • -o ~/hello-secret-manager.zip : This curl option redirects the downloaded zip file to a local file named hello-secret-manager.zip.

Create and test a REST controller

1. In Cloud Shell, to create a new class file, run the following command:

   cat > ~/hello-secret-manager/src/main/java/com/example/HelloSecretManager/HelloSecretManagerController.java <<EOF package com.example.HelloSecretManager; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class HelloSecretManagerController { String greeting = "Hi"; @GetMapping("/") public String hello() { return greeting + " World!"; } } EOF

   A GET request to "/" should return the string "Hi World!"

2. To use the correct Java version, run the following command:

   export JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64

3. To start the REST service, run the following command:

   cd ~/hello-secret-manager ./mvnw -DskipTests spring-boot:run | tee verify_response.txt

   The Maven wrapper command invokes mvnw in the current directory. Any tests would be skipped. The Maven goal spring-boot:run compiles the code, and then packages and launches the application.

4. To access the REST service in the web browser, click Web Preview, and then select Preview on port 8080.

   

   A new tab is opened in the browser, and the application is running. This is the root URL, which displays "Hi World!"

5. To quit the application, in Cloud Shell, enter CTRL-C.

Verify progress

• To allow progress to be verified, run the following commands to copy the files to the Cloud Storage bucket named .

  gsutil -m cp -r ~/hello-secret-manager/verify_response.txt gs://{{{project_0.startup_script.gcs_bucket|GCS bucket name}}} gsutil -m cp -r ~/hello-secret-manager/pom.xml gs://{{{project_0.startup_script.gcs_bucket|GCS bucket name}}}

Click Check my progress to verify the objective. Create a new Spring Boot REST service

Task 2. Configure a secret in Secret Manager

Secret Manager is a secure and convenient storage system for API keys, passwords, certificates, and other sensitive data.

In this task, you enable the Secret Manager API and configure a secret.

Enable the Secret Manager API

• To enable the Secret Manager API, in Cloud Shell, run the following command:

  gcloud services enable secretmanager.googleapis.com

Create a secret in Secret Manager

1. To create the secret, run the following command:

   echo -n "Hello" | \ gcloud secrets create greeting --data-file=-

   This command echoes to STDIN and specifies - as the data file, which causes STDIN to be used as the source for the secret value.

2. To list all available secrets, run the following command:

   gcloud secrets list

   The command lists the secret greeting.

Click Check my progress to verify the objective. Configure a secret in Secret Manager

Task 3. Update the app to use the secret greeting

In this task, you update the Java application to retrieve the secret greeting from Secret Manager and display it.

Add the Secret Manager dependency

A Secret Manager dependency must be added to the pom.xml file before the app will be able to access secrets.

1. In Cloud Shell, click Open Editor.

   The Cloud Shell Editor opens.

2. In the Cloud Shell Editor, navigate to ~/hello-secret-manager/pom.xml.

3. In the <dependencies> node, below the spring-cloud-gcp-starter dependency, add the Secret Manager starter dependency:

   <dependency> <groupId>com.google.cloud</groupId> <artifactId>spring-cloud-gcp-starter-secretmanager</artifactId> </dependency>

   The dependencies node should now look like this:

   <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>com.google.cloud</groupId> <artifactId>spring-cloud-gcp-starter</artifactId> </dependency> <dependency> <groupId>com.google.cloud</groupId> <artifactId>spring-cloud-gcp-starter-secretmanager</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies>

   This starter simplifies the process of accessing secrets stored in Secret Manager from your Spring Boot application, allowing you to easily retrieve secrets as if they were regular application properties.

Add an application property

1. Navigate to ~/hello-secret-manager/src/main/resources/application.properties.

2. Below the spring.application.name property, add the following property:

   spring.config.import=sm://

   The property configures a Spring PropertySource for accessing Secret Manager secrets.

Modify the controller code to use the secret

1. Navigate to ~/hello-secret-manager/src/main/java/com/example/HelloSecretManager/HelloSecretManagerController.java.

2. Insert the following import statement beneath the other imports:

   import org.springframework.beans.factory.annotation.Value;

   This imports the Value annotation, which can be used to inject a value into a variable.

3. Change the greeting variable from this:

   String greeting = "Hi";

   to this:

   @Value("${sm://greeting}") String greeting;

   The new code retrieves the latest version of the secret named greeting from Secret Manager and stores it in the variable.

Test the application

1. To return to Cloud Shell, click Open Terminal.

2. To start the REST service, run the following commands:

   cd ~/hello-secret-manager export JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64 ./mvnw -DskipTests spring-boot:run | tee verify_test_response.txt

3. To access the REST service in the web browser, click Web Preview, and then select Preview on port 8080.

   A new tab is opened in the browser, and the application is running. This time the app uses the secret to display "Hello World!"

4. To quit the application, in Cloud Shell, enter CTRL-C.

Verify progress

• To allow progress to be verified, run the following commands to move the files to the Cloud Storage bucket.

  gsutil -m cp -r ~/hello-secret-manager/verify_test_response.txt gs://{{{project_0.startup_script.gcs_bucket|GCS bucket name}}} gsutil -m cp -r ~/hello-secret-manager/src/main/java/com/example/HelloSecretManager/HelloSecretManagerController.java gs://{{{project_0.startup_script.gcs_bucket|GCS bucket name}}}

Click Check my progress to verify the objective. Update the app to use the secret greeting

Task 4. Deploy the app to Cloud Run

In this task, you deploy the app to Cloud Run. You use a buildpack to automatically create a container for the Java application.

Enable the Cloud Run and Cloud Build APIs

• To enable the Cloud Run and Cloud Build APIs, in Cloud Shell, run the following command:

  gcloud services enable run.googleapis.com cloudbuild.googleapis.com

Update application.properties

1. Navigate to ~/hello-secret-manager/src/main/resources/application.properties.

2. Below the spring.config.import property, add the following property:

   server.port=${PORT:8080}

   The property specifies that the environment variable PORT will be used as the port that listens for requests. By default, Cloud Run requests are sent to port 8080, so that is the default used.

Specify Java version in the build project descriptor

A build project descriptor file provides information to Cloud Build for the building of the containeraized app.

• To create the build project descriptor file, run the following command:

  cat > ~/hello-secret-manager/project.toml <<EOF [[build.env]] name = "GOOGLE_RUNTIME_VERSION" value = "21" EOF

  The project.toml file in the app root directory specifies that the GOOGLE_RUNTIME_VERSION environment variable will be set to 21, indicating that Java version 21 should be used to compile the application.

Create a service account for the Cloud Run service

To ensure that only the required permissions are given to the Cloud Run app, a service account is created for the app.

1. To create a service account named hello-secret-manager-run-sa, run the following command:

   gcloud iam service-accounts create hello-secret-manager-run-sa

2. To allow this service account to access secrets in Secret Manager, run the following command:

   gcloud projects add-iam-policy-binding ${GOOGLE_CLOUD_PROJECT} \ --member="serviceAccount:hello-secret-manager-run-sa@${GOOGLE_CLOUD_PROJECT}.iam.gserviceaccount.com" \ --role="roles/secretmanager.secretAccessor"

Change the secret greeting

• To change update the secret, run the following command:

  echo -n "Greetings" | \ gcloud secrets versions add greeting --data-file=-

  When the Cloud Run app is deployed, it should use this new version of the secret.

Deploy the app to Cloud Run

1. To deploy the app to Cloud Run, run the following command:

   gcloud run deploy hello-secret-manager \ --region={{{ project_0.default_region | REGION }}} \ --allow-unauthenticated \ --service-account=hello-secret-manager-run-sa@${GOOGLE_CLOUD_PROJECT}.iam.gserviceaccount.com \ --source .

   This command deploys the app to Cloud Run with the name hello-secret-manager.

   • --region : The region for deployment.
   • --allow-unauthenticated : Makes your Cloud Run service publicly accessible without requiring any authentication. This flag should not be used for sensitive applications.
   • --service-account : Specifies the service account, and therefore the permissions allowed by the app.
   • --source : Specifies the source root directory. Specifying the source directory instead of a container indicates that Cloud Build should build the container.

   After a few minutes, the deployment completes.

2. To get the application URL, run the following command:

   echo "https://hello-secret-manager-$(gcloud projects describe $GOOGLE_CLOUD_PROJECT --format="value(projectNumber)").{{{ project_0.default_region | REGION }}}.run.app"

3. Click the link created by the previous command.

   A new tab opens and the message "Greetings World!" is displayed.

Click Check my progress to verify the objective. Deploy the app to Cloud Run

Congratulations!

In this lab, you stored a secret in Secret Manager, built a Spring Boot app that retrieves and displays the secret, and deployed that app to Cloud Run.

Next steps / Learn more

Check out the following resource to learn more about using Spring Boot on Google Cloud:

• Use Spring Boot to quickly create apps for Google Cloud

Manual Last Updated March 12, 2025

Lab Last Tested March 12, 2025

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