Add Support for S3 as Lock Storage Backend

README.md

@@ -44,6 +44,7 @@ executed repeatedly. Moreover, the locks are time-based and ShedLock assumes tha
   - [In-Memory](#in-memory)
   - [Memcached](#memcached-using-spymemcached)
   - [Datastore](#datastore)
+  - [S3](#s3)
 + [Multi-tenancy](#multi-tenancy)
 + [Customization](#customization)
 + [Duration specification](#duration-specification)
@@ -885,6 +886,28 @@ public LockProvider lockProvider(DatabaseClient databaseClient) {
 }
 ```
 
+#### S3
+
+Import the project
+```xml
+<dependency>
+    <groupId>net.javacrumbs.shedlock</groupId>
+    <artifactId>shedlock-provider-s3</artifactId>
+    <version>6.0.2</version>
+</dependency>
+```
+
+and configure
+```java
+import net.javacrumbs.shedlock.provider.s3.S3LockProvider;
+
+...
+
+@Bean
+public LockProvider lockProvider(com.amazonaws.services.s3.AmazonS3 amazonS3) {
+    return new S3LockProvider(amazonS3, "BUCKET_NAME");
+}
+```
 
 ## Multi-tenancy
 If you have multi-tenancy use-case you can use a lock provider similar to this one

pom.xml

@@ -63,6 +63,7 @@
         <module>providers/datastore/shedlock-provider-datastore</module>
         <module>providers/spanner/shedlock-provider-spanner</module>
         <module>providers/neo4j/shedlock-provider-neo4j</module>
+        <module>providers/s3/shedlock-provider-s3</module>
     </modules>
 
     <properties>

providers/s3/shedlock-provider-s3/pom.xml

@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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">
+    <parent>
+        <artifactId>shedlock-parent</artifactId>
+        <groupId>net.javacrumbs.shedlock</groupId>
+        <version>6.0.3-SNAPSHOT</version>
+        <relativePath>../../../pom.xml</relativePath>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>shedlock-provider-s3</artifactId>
+    <version>6.0.3-SNAPSHOT</version>
+
+    <properties>
+        <aws-java-sdk-s3.version>1.12.747</aws-java-sdk-s3.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>net.javacrumbs.shedlock</groupId>
+            <artifactId>shedlock-core</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-java-sdk-s3</artifactId>
+            <version>${aws-java-sdk-s3.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>${test-containers.ver}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>localstack</artifactId>
+            <version>${test-containers.ver}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>net.javacrumbs.shedlock</groupId>
+            <artifactId>shedlock-test-support</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback.ver}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <configuration>
+                    <archive>
+                        <manifestEntries>
+                            <Automatic-Module-Name>
+                                net.javacrumbs.shedlock.provider.s3
+                            </Automatic-Module-Name>
+                        </manifestEntries>
+                    </archive>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

providers/s3/shedlock-provider-s3/src/main/java/net/javacrumbs/shedlock/provider/s3/Lock.java

@@ -0,0 +1,5 @@
+package net.javacrumbs.shedlock.provider.s3;
+
+import java.time.Instant;
+
+record Lock(Instant lockUntil, Instant lockedAt, String lockedBy, String eTag) {}

providers/s3/shedlock-provider-s3/src/main/java/net/javacrumbs/shedlock/provider/s3/S3LockProvider.java

@@ -0,0 +1,31 @@
+package net.javacrumbs.shedlock.provider.s3;
+
+import com.amazonaws.services.s3.AmazonS3;
+import net.javacrumbs.shedlock.support.StorageBasedLockProvider;
+
+/**
+ * Lock provider implementation for S3.
+ */
+public class S3LockProvider extends StorageBasedLockProvider {
+
+    /**
+     * Constructs an S3LockProvider.
+     *
+     * @param s3Client   Amazon S3 client used to interact with the S3 bucket.
+     * @param bucketName The name of the S3 bucket where locks are stored.
+     * @param objectPrefix The prefix of the S3 object lock.
+     */
+    public S3LockProvider(AmazonS3 s3Client, String bucketName, String objectPrefix) {
+        super(new S3StorageAccessor(s3Client, bucketName, objectPrefix));
+    }
+
+    /**
+     * Constructs an S3LockProvider.
+     *
+     * @param s3Client   Amazon S3 client used to interact with the S3 bucket.
+     * @param bucketName The name of the S3 bucket where locks are stored.
+     */
+    public S3LockProvider(AmazonS3 s3Client, String bucketName) {
+        this(s3Client, bucketName, "shedlock/");
+    }
+}

providers/s3/shedlock-provider-s3/src/main/java/net/javacrumbs/shedlock/provider/s3/S3StorageAccessor.java

@@ -0,0 +1,189 @@
+package net.javacrumbs.shedlock.provider.s3;
+
+import static net.javacrumbs.shedlock.core.ClockProvider.now;
+
+import com.amazonaws.AmazonServiceException;
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.model.ObjectMetadata;
+import com.amazonaws.services.s3.model.PutObjectRequest;
+import com.amazonaws.services.s3.model.PutObjectResult;
+import java.io.ByteArrayInputStream;
+import java.nio.ByteBuffer;
+import java.time.Instant;
+import java.util.Optional;
+import java.util.UUID;
+import net.javacrumbs.shedlock.core.LockConfiguration;
+import net.javacrumbs.shedlock.support.AbstractStorageAccessor;
+
+/**
+ * Implementation of StorageAccessor for S3 as a lock storage backend.
+ * Manages locks using S3 objects with metadata for expiration and conditional writes.
+ */
+class S3StorageAccessor extends AbstractStorageAccessor {
+
+    private static final String LOCK_UNTIL = "lockUntil";
+    private static final String LOCKED_AT = "lockedAt";
+    private static final String LOCKED_BY = "lockedBy";
+    private static final int PRECONDITION_FAILED = 412;
+
+    private final AmazonS3 s3Client;
+    private final String bucketName;
+    private final String objectPrefix;
+
+    public S3StorageAccessor(AmazonS3 s3Client, String bucketName, String objectPrefix) {
+        this.s3Client = s3Client;
+        this.bucketName = bucketName;
+        this.objectPrefix = objectPrefix;
+    }
+
+    /**
+     * Finds the lock in the S3 bucket.
+     */
+    Optional<Lock> find(String name, String action) {
+        try {
+            ObjectMetadata metadata = s3Client.getObjectMetadata(bucketName, objectName(name));
+            Instant lockUntil = Instant.parse(metadata.getUserMetaDataOf(LOCK_UNTIL));
+            Instant lockedAt = Instant.parse(metadata.getUserMetaDataOf(LOCKED_AT));
+            String lockedBy = metadata.getUserMetaDataOf(LOCKED_BY);
+            String eTag = metadata.getETag();
+
+            logger.debug("Lock found. action: {}, name: {}, lockUntil: {}, e-tag: {}", action, name, lockUntil, eTag);
+            return Optional.of(new Lock(lockUntil, lockedAt, lockedBy, eTag));
+        } catch (AmazonServiceException e) {
+            if (e.getStatusCode() == 404) {
+                logger.debug("Lock not found. action: {}, name: {}", action, name);
+                return Optional.empty();
+            }
+            throw e;
+        }
+    }
+
+    @Override
+    public boolean insertRecord(LockConfiguration lockConfiguration) {
+        String name = lockConfiguration.getName();
+        if (find(name, "insertRecord").isPresent()) {
+            logger.debug("Lock already exists. name: {}", name);
+            return false;
+        }
+
+        try {
+            var lockContent = getLockContent();
+            ObjectMetadata metadata = createMetadata(lockConfiguration.getLockAtMostUntil(), now(), getHostname());
+            metadata.setContentLength(lockContent.length);
+
+            PutObjectRequest request =
+                    new PutObjectRequest(bucketName, objectName(name), new ByteArrayInputStream(lockContent), metadata);
+            request.putCustomRequestHeader("If-None-Match", "*");
+
+            s3Client.putObject(request);
+            logger.debug("Lock created successfully. name: {}, metadata: {}", name, metadata.getUserMetadata());
+            return true;
+        } catch (AmazonServiceException e) {
+            if (e.getStatusCode() == PRECONDITION_FAILED) {
+                logger.debug("Lock already in use. name: {}", name);
+            } else {
+                logger.warn("Failed to create lock. name: {}", name, e);
+            }
+            return false;
+        }
+    }
+
+    @Override
+    public boolean updateRecord(LockConfiguration lockConfiguration) {
+        Optional<Lock> lock = find(lockConfiguration.getName(), "updateRecord");
+        if (lock.isEmpty()) {
+            logger.warn("Update skipped. Lock not found. name: {}, lock: {}", lockConfiguration.getName(), lock);
+            return false;
+        }
+        if (lock.get().lockUntil().isAfter(now())) {
+            logger.debug("Update skipped. Lock still valid. name: {}, lock: {}", lockConfiguration.getName(), lock);
+            return false;
+        }
+
+        ObjectMetadata newMetadata = createMetadata(lockConfiguration.getLockAtMostUntil(), now(), getHostname());
+        return replaceObjectMetadata(
+                lockConfiguration.getName(), newMetadata, lock.get().eTag(), "updateRecord");
+    }
+
+    @Override
+    public void unlock(LockConfiguration lockConfiguration) {
+        Optional<Lock> lock = find(lockConfiguration.getName(), "unlock");
+        if (lock.isEmpty()) {
+            logger.warn("Unlock skipped. Lock not found. name: {}, lock: {}", lockConfiguration.getName(), lock);
+            return;
+        }
+
+        updateUntil(lockConfiguration.getName(), lock.get(), lockConfiguration.getUnlockTime(), "unlock");
+    }
+
+    @Override
+    public boolean extend(LockConfiguration lockConfiguration) {
+        Optional<Lock> lock = find(lockConfiguration.getName(), "extend");
+        if (lock.isEmpty()
+                || lock.get().lockUntil().isBefore(now())
+                || !lock.get().lockedBy().equals(getHostname())) {
+            logger.debug(
+                    "Extend skipped. Lock invalid or not owned by host. name: {}, lock: {}",
+                    lockConfiguration.getName(),
+                    lock);
+            return false;
+        }
+
+        return updateUntil(lockConfiguration.getName(), lock.get(), lockConfiguration.getLockAtMostUntil(), "extend");
+    }
+
+    private boolean updateUntil(String name, Lock lock, Instant until, String action) {
+        ObjectMetadata existingMetadata = s3Client.getObjectMetadata(bucketName, objectName(name));
+        ObjectMetadata newMetadata =
+                createMetadata(until, Instant.parse(existingMetadata.getUserMetaDataOf(LOCKED_AT)), getHostname());
+
+        return replaceObjectMetadata(name, newMetadata, lock.eTag(), action);
+    }
+
+    private boolean replaceObjectMetadata(String name, ObjectMetadata newMetadata, String eTag, String action) {
+        var lockContent = getLockContent();
+        newMetadata.setContentLength(lockContent.length);
+
+        PutObjectRequest request =
+                new PutObjectRequest(bucketName, objectName(name), new ByteArrayInputStream(lockContent), newMetadata);
+        request.putCustomRequestHeader("If-Match", eTag);
+
+        try {
+            PutObjectResult response = s3Client.putObject(request);
+            logger.debug(
+                    "Lock {} successfully. name: {}, old e-tag: {}, new e-tag: {}",
+                    action,
+                    name,
+                    eTag,
+                    response.getETag());
+            return true;
+        } catch (AmazonServiceException e) {
+            if (e.getStatusCode() == PRECONDITION_FAILED) {
+                logger.debug("Lock not exists to {}. name: {}, e-tag {}", action, name, eTag);
+            } else {
+                logger.warn("Failed to {} lock. name: {}", action, name, e);
+            }
+            return false;
+        }
+    }
+
+    private static byte[] getLockContent() {
+        var uuid = UUID.randomUUID();
+        ByteBuffer bb = ByteBuffer.wrap(new byte[16]);
+        bb.putLong(uuid.getMostSignificantBits());
+        bb.putLong(uuid.getLeastSignificantBits());
+        return bb.array();
+    }
+
+    private ObjectMetadata createMetadata(Instant lockUntil, Instant lockedAt, String lockedBy) {
+        ObjectMetadata metadata = new ObjectMetadata();
+        metadata.addUserMetadata(LOCK_UNTIL, lockUntil.toString());
+        metadata.addUserMetadata(LOCKED_AT, lockedAt.toString());
+        metadata.addUserMetadata(LOCKED_BY, lockedBy);
+        return metadata;
+    }
+
+    private String objectName(String name) {
+        return objectPrefix + name;
+    }
+}