Uso dei segreti in Secrets Manager nelle funzioni Lambda

Crea e vai in una nuova directory di progetto. Esempio:

mkdir my_function
cd my_function

Crea un file denominato lambda_function.py con il codice seguente. Per secret_name, utilizza il nome o il nome della risorsa Amazon (ARN) del segreto.

import json
import os
import requests

def lambda_handler(event, context):
    try:
        # Replace with the name or ARN of your secret
        secret_name = "arn:aws:secretsmanager:us-east-1:111122223333:secret:SECRET_NAME"
        
        secrets_extension_endpoint = f"http://localhost:2773/secretsmanager/get?secretId={secret_name}"
        headers = {"X-Aws-Parameters-Secrets-Token": os.environ.get('AWS_SESSION_TOKEN')}
        
        response = requests.get(secrets_extension_endpoint, headers=headers)
        print(f"Response status code: {response.status_code}")
        
        secret = json.loads(response.text)["SecretString"]
        print(f"Retrieved secret: {secret}")
        
        return {
            'statusCode': response.status_code,
            'body': json.dumps({
                'message': 'Successfully retrieved secret',
                'secretRetrieved': True
            })
        }
    
    except Exception as e:
        print(f"Error: {str(e)}")
        return {
            'statusCode': 500,
            'body': json.dumps({
                'message': 'Error retrieving secret',
                'error': str(e)
            })
        }

Creare un file denominato requirements.txt con il seguente contenuto:

requests

Installare le dipendenze:

pip install -r requirements.txt -t .

Crea un file .zip contenente tutti i file:

zip -r function.zip .

Crea e vai in una nuova directory di progetto. Esempio:

mkdir my_function
cd my_function

Crea un file denominato index.mjs con il codice seguente. Per secret_name, utilizza il nome o il nome della risorsa Amazon (ARN) del segreto.

import http from 'http';

export const handler = async (event) => {
    try {
        // Replace with the name or ARN of your secret
        const secretName = "arn:aws:secretsmanager:us-east-1:111122223333:secret:SECRET_NAME";
        const options = {
            hostname: 'localhost',
            port: 2773,
            path: `/secretsmanager/get?secretId=${secretName}`,
            headers: {
                'X-Aws-Parameters-Secrets-Token': process.env.AWS_SESSION_TOKEN
            }
        };

        const response = await new Promise((resolve, reject) => {
            http.get(options, (res) => {
                let data = '';
                res.on('data', (chunk) => { data += chunk; });
                res.on('end', () => {
                    resolve({ 
                        statusCode: res.statusCode, 
                        body: data 
                    });
                });
            }).on('error', reject);
        });

        const secret = JSON.parse(response.body).SecretString;
        console.log('Retrieved secret:', secret);

        return {
            statusCode: response.statusCode,
            body: JSON.stringify({
                message: 'Successfully retrieved secret',
                secretRetrieved: true
            })
        };
    } catch (error) {
        console.error('Error:', error);
        return {
            statusCode: 500,
            body: JSON.stringify({
                message: 'Error retrieving secret',
                error: error.message
            })
        };
    }
};

Crea un file .zip contenente il file index.mjs:

zip -r function.zip index.mjs

Crea un progetto Maven:

mvn archetype:generate \
    -DgroupId=example \
    -DartifactId=lambda-secrets-demo \
    -DarchetypeArtifactId=maven-archetype-quickstart \
    -DarchetypeVersion=1.4 \
    -DinteractiveMode=false

Vai alla directory del progetto:

cd lambda-secrets-demo

Apri pom.xml e sostituisci il contenuto con quanto riportato di seguito.

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>example</groupId>
    <artifactId>lambda-secrets-demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-lambda-java-core</artifactId>
            <version>1.2.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.2.4</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <createDependencyReducedPom>false</createDependencyReducedPom>
                            <finalName>function</finalName>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Rinomina /lambda-secrets-demo/src/main/java/example/App.java in Hello.java in modo che corrisponda al nome del gestore Java predefinito di Lambda (example.Hello::handleRequest):

mv src/main/java/example/App.java src/main/java/example/Hello.java

Apri il file Hello.java e sostituisci il contenuto con quanto riportato di seguito. Per secretName, utilizza il nome o il nome della risorsa Amazon (ARN) del segreto.

package example;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class Hello implements RequestHandler<Object, String> {
    private final HttpClient client = HttpClient.newHttpClient();

    @Override
    public String handleRequest(Object input, Context context) {
        try {
            // Replace with the name or ARN of your secret
            String secretName = "arn:aws:secretsmanager:us-east-1:111122223333:secret:SECRET_NAME";
            String endpoint = "http://localhost:2773/secretsmanager/get?secretId=" + secretName;

            HttpRequest request = HttpRequest.newBuilder()
                .uri(URI.create(endpoint))
                .header("X-Aws-Parameters-Secrets-Token", System.getenv("AWS_SESSION_TOKEN"))
                .GET()
                .build();

            HttpResponse<String> response = client.send(request, 
                HttpResponse.BodyHandlers.ofString());

            String secret = response.body();
            secret = secret.substring(secret.indexOf("SecretString") + 15);
            secret = secret.substring(0, secret.indexOf("\""));

            System.out.println("Retrieved secret: " + secret);
            return String.format(
                "{\"statusCode\": %d, \"body\": \"%s\"}",
                response.statusCode(), "Successfully retrieved secret"
            );

        } catch (Exception e) {
            e.printStackTrace();
            return String.format(
                "{\"body\": \"Error retrieving secret: %s\"}", 
                e.getMessage()
            );
        }
    }
}

Rimuovi la directory di test. Maven la crea per impostazione predefinita, ma non ne abbiamo bisogno per questo esempio.

rm -rf src/test

Compila il progetto:

mvn package

Scarica il file JAR (target/function.jar) per un uso successivo.