Use PutObjectLockConfiguration with an Amazon SDK or CLI

Set the object lock configuration of a bucket.

    /// <summary>
    /// Enable object lock on an existing bucket.
    /// </summary>
    /// <param name="bucketName">The name of the bucket to modify.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> EnableObjectLockOnBucket(string bucketName)
    {
        try
        {
            // First, enable Versioning on the bucket.
            await _amazonS3.PutBucketVersioningAsync(new PutBucketVersioningRequest()
            {
                BucketName = bucketName,
                VersioningConfig = new S3BucketVersioningConfig()
                {
                    EnableMfaDelete = false,
                    Status = VersionStatus.Enabled
                }
            });

            var request = new PutObjectLockConfigurationRequest()
            {
                BucketName = bucketName,
                ObjectLockConfiguration = new ObjectLockConfiguration()
                {
                    ObjectLockEnabled = new ObjectLockEnabled("Enabled"),
                },
            };

            var response = await _amazonS3.PutObjectLockConfigurationAsync(request);
            Console.WriteLine($"\tAdded an object lock policy to bucket {bucketName}.");
            return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
        }
        catch (AmazonS3Exception ex)
        {
            Console.WriteLine($"Error modifying object lock: '{ex.Message}'");
            return false;
        }
    }

Set the default retention period of a bucket.

    /// <summary>
    /// Set or modify a retention period on an S3 bucket.
    /// </summary>
    /// <param name="bucketName">The bucket to modify.</param>
    /// <param name="retention">The retention mode.</param>
    /// <param name="retainUntilDate">The date for retention until.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> ModifyBucketDefaultRetention(string bucketName, bool enableObjectLock, ObjectLockRetentionMode retention, DateTime retainUntilDate)
    {
        var enabledString = enableObjectLock ? "Enabled" : "Disabled";
        var timeDifference = retainUntilDate.Subtract(DateTime.Now);
        try
        {
            // First, enable Versioning on the bucket.
            await _amazonS3.PutBucketVersioningAsync(new PutBucketVersioningRequest()
            {
                BucketName = bucketName,
                VersioningConfig = new S3BucketVersioningConfig()
                {
                    EnableMfaDelete = false,
                    Status = VersionStatus.Enabled
                }
            });

            var request = new PutObjectLockConfigurationRequest()
            {
                BucketName = bucketName,
                ObjectLockConfiguration = new ObjectLockConfiguration()
                {
                    ObjectLockEnabled = new ObjectLockEnabled(enabledString),
                    Rule = new ObjectLockRule()
                    {
                        DefaultRetention = new DefaultRetention()
                        {
                            Mode = retention,
                            Days = timeDifference.Days // Can be specified in days or years but not both.
                        }
                    }
                }
            };

            var response = await _amazonS3.PutObjectLockConfigurationAsync(request);
            Console.WriteLine($"\tAdded a default retention to bucket {bucketName}.");
            return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
        }
        catch (AmazonS3Exception ex)
        {
            Console.WriteLine($"\tError modifying object lock: '{ex.Message}'");
            return false;
        }
    }

To set an object lock configuration on a bucket

The following put-object-lock-configuration example sets a 50-day object lock on the specified bucket.

aws s3api put-object-lock-configuration \
    --bucket my-bucket-with-object-lock \
    --object-lock-configuration '{ "ObjectLockEnabled": "Enabled", "Rule": { "DefaultRetention": { "Mode": "COMPLIANCE", "Days": 50 }}}'

This command produces no output.

Set the object lock configuration of a bucket.

    // Enable object lock on an existing bucket.
    public void enableObjectLockOnBucket(String bucketName) {
        try {
            VersioningConfiguration versioningConfiguration = VersioningConfiguration.builder()
                .status(BucketVersioningStatus.ENABLED)
                .build();

            PutBucketVersioningRequest putBucketVersioningRequest = PutBucketVersioningRequest.builder()
                .bucket(bucketName)
                .versioningConfiguration(versioningConfiguration)
                .build();

            // Enable versioning on the bucket.
            getClient().putBucketVersioning(putBucketVersioningRequest);
            PutObjectLockConfigurationRequest request = PutObjectLockConfigurationRequest.builder()
                .bucket(bucketName)
                .objectLockConfiguration(ObjectLockConfiguration.builder()
                    .objectLockEnabled(ObjectLockEnabled.ENABLED)
                    .build())
                .build();

            getClient().putObjectLockConfiguration(request);
            System.out.println("Successfully enabled object lock on "+bucketName);

        } catch (S3Exception ex) {
            System.out.println("Error modifying object lock: '" + ex.getMessage() + "'");
        }
    }

Set the default retention period of a bucket.

    // Set or modify a retention period on an S3 bucket.
    public void modifyBucketDefaultRetention(String bucketName) {
        VersioningConfiguration versioningConfiguration = VersioningConfiguration.builder()
            .mfaDelete(MFADelete.DISABLED)
            .status(BucketVersioningStatus.ENABLED)
            .build();

        PutBucketVersioningRequest versioningRequest = PutBucketVersioningRequest.builder()
            .bucket(bucketName)
            .versioningConfiguration(versioningConfiguration)
            .build();

        getClient().putBucketVersioning(versioningRequest);
        DefaultRetention rention = DefaultRetention.builder()
            .days(1)
            .mode(ObjectLockRetentionMode.GOVERNANCE)
            .build();

        ObjectLockRule lockRule = ObjectLockRule.builder()
            .defaultRetention(rention)
            .build();

        ObjectLockConfiguration objectLockConfiguration = ObjectLockConfiguration.builder()
            .objectLockEnabled(ObjectLockEnabled.ENABLED)
            .rule(lockRule)
            .build();

        PutObjectLockConfigurationRequest putObjectLockConfigurationRequest = PutObjectLockConfigurationRequest.builder()
            .bucket(bucketName)
            .objectLockConfiguration(objectLockConfiguration)
            .build();

        getClient().putObjectLockConfiguration(putObjectLockConfigurationRequest) ;
        System.out.println("Added a default retention to bucket "+bucketName +".");
    }