chore: extend examples to fetch momento auth token from secrets manager

examples/lib/build.gradle.kts

@@ -18,6 +18,8 @@ repositories {
 
 dependencies {
     implementation("software.momento.java:sdk:1.0.0")
+    // For examples to store secrets in AWS Secrets Manager
+    implementation("software.amazon.awssdk:secretsmanager:2.20.93")
 
     // Logging framework to log and enable logging in the Momento client.
     implementation("ch.qos.logback:logback-classic:1.4.7")

examples/lib/src/main/java/momento/client/example/BasicExample.java

@@ -26,7 +26,7 @@ public class BasicExample {
   public static void main(String[] args) {
     logStartBanner(logger);
 
-    final CredentialProvider credentialProvider = AuthUtil.getCredentials();
+    final CredentialProvider credentialProvider = AuthUtil.getCredentialsFromEnvironmentVariable();
 
     try (final CacheClient client =
         CacheClient.builder(credentialProvider, Configurations.Laptop.latest(), DEFAULT_ITEM_TTL)

examples/lib/src/main/java/momento/client/example/DictionaryExample.java

@@ -28,7 +28,7 @@ public class DictionaryExample {
   public static void main(String[] args) {
     logStartBanner(logger);
 
-    final CredentialProvider credentialProvider = AuthUtil.getCredentials();
+    final CredentialProvider credentialProvider = AuthUtil.getCredentialsFromEnvironmentVariable();
 
     try (final CacheClient client =
         CacheClient.builder(credentialProvider, Configurations.Laptop.latest(), DEFAULT_ITEM_TTL)

examples/lib/src/main/java/momento/client/example/ListExample.java

@@ -28,7 +28,7 @@ public class ListExample {
   public static void main(String[] args) {
     logStartBanner(logger);
 
-    final CredentialProvider credentialProvider = AuthUtil.getCredentials();
+    final CredentialProvider credentialProvider = AuthUtil.getCredentialsFromEnvironmentVariable();
 
     try (final CacheClient client =
         CacheClient.builder(credentialProvider, Configurations.Laptop.latest(), DEFAULT_ITEM_TTL)

examples/lib/src/main/java/momento/client/example/SetExample.java

@@ -27,7 +27,7 @@ public class SetExample {
   public static void main(String[] args) {
     logStartBanner(logger);
 
-    final CredentialProvider credentialProvider = AuthUtil.getCredentials();
+    final CredentialProvider credentialProvider = AuthUtil.getCredentialsFromEnvironmentVariable();
 
     try (final CacheClient client =
         CacheClient.builder(credentialProvider, Configurations.Laptop.latest(), DEFAULT_ITEM_TTL)

examples/lib/src/main/java/momento/client/example/SortedSetExample.java

@@ -35,7 +35,7 @@ public class SortedSetExample {
   public static void main(String[] args) {
     logStartBanner(logger);
 
-    final CredentialProvider credentialProvider = AuthUtil.getCredentials();
+    final CredentialProvider credentialProvider = AuthUtil.getCredentialsFromEnvironmentVariable();
 
     try (final CacheClient client =
         CacheClient.builder(credentialProvider, Configurations.Laptop.latest(), DEFAULT_ITEM_TTL)

examples/lib/src/main/java/momento/client/example/util/AuthUtil.java

@@ -1,22 +1,53 @@
 package momento.client.example.util;
 
 import momento.sdk.auth.CredentialProvider;
-import momento.sdk.auth.EnvVarCredentialProvider;
 import momento.sdk.exceptions.SdkException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider;
+import software.amazon.awssdk.regions.Region;
+import software.amazon.awssdk.services.secretsmanager.SecretsManagerClient;
+import software.amazon.awssdk.services.secretsmanager.model.GetSecretValueRequest;
+import software.amazon.awssdk.services.secretsmanager.model.GetSecretValueResponse;
 
 /** Small utility class to vend credentials */
 public class AuthUtil {
-  private static final String AUTH_TOKEN_ENV_VAR = "MOMENTO_AUTH_TOKEN";
+  private static final String AUTH_TOKEN_VAR = "MOMENTO_AUTH_TOKEN";
   private static final Logger logger = LoggerFactory.getLogger(AuthUtil.class);
 
-  public static CredentialProvider getCredentials() {
+  public static CredentialProvider getCredentialsFromEnvironmentVariable() {
     try {
-      return new EnvVarCredentialProvider(AUTH_TOKEN_ENV_VAR);
+      return CredentialProvider.fromEnvVar(AUTH_TOKEN_VAR);
     } catch (SdkException e) {
-      logger.error("Unable to load credential from environment variable " + AUTH_TOKEN_ENV_VAR, e);
+      logger.error("Unable to load credential from environment variable " + AUTH_TOKEN_VAR, e);
       throw e;
     }
   }
+
+  public static CredentialProvider getCredentialsFromSecretsManagerAuthToken() {
+    final Region region = Region.of("us-east-1");
+
+    // Create a Secrets Manager client
+    final SecretsManagerClient client =
+        SecretsManagerClient.builder()
+            .region(region)
+            .credentialsProvider(DefaultCredentialsProvider.create())
+            .build();
+
+    final GetSecretValueRequest getSecretValueRequest =
+        GetSecretValueRequest.builder().secretId(AUTH_TOKEN_VAR).build();
+
+    final GetSecretValueResponse getSecretValueResponse;
+
+    try {
+      getSecretValueResponse = client.getSecretValue(getSecretValueRequest);
+    } catch (Exception e) {
+      // For a list of exceptions thrown, see
+      // https://docs.aws.amazon.com/secretsmanager/latest/apireference/API_GetSecretValue.html
+      throw e;
+    }
+
+    final String secret = getSecretValueResponse.secretString();
+    return CredentialProvider.fromString(secret);
+  }
 }