Module Values.HeadObjectOutputSource

The HEAD operation retrieves metadata from an object without returning the object itself. This operation is useful if you're interested only in an object's metadata. A HEAD request has the same options as a GET operation on an object. The response is identical to the GET response except that there is no response body. Because of this, if the HEAD request generates an error, it returns a generic code, such as 400 Bad Request, 403 Forbidden, 404 Not Found, 405 Method Not Allowed, 412 Precondition Failed, or 304 Not Modified. It's not possible to retrieve the exact exception of these error codes. Request headers are limited to 8 KB in size. For more information, see Common Request Headers. Permissions General purpose bucket permissions - To use HEAD, you must have the s3:GetObject permission. You need the relevant read object (or version) permission for this operation. For more information, see Actions, resources, and condition keys for Amazon S3 in the Amazon S3 User Guide. For more information about the permissions to S3 API operations by S3 resource types, see Required permissions for Amazon S3 API operations in the Amazon S3 User Guide. If the object you request doesn't exist, the error that Amazon S3 returns depends on whether you also have the s3:ListBucket permission. If you have the s3:ListBucket permission on the bucket, Amazon S3 returns an HTTP status code 404 Not Found error. If you don’t have the s3:ListBucket permission, Amazon S3 returns an HTTP status code 403 Forbidden error. Directory bucket permissions - To grant access to this API operation on a directory bucket, we recommend that you use the CreateSession API operation for session-based authorization. Specifically, you grant the s3express:CreateSession permission to the directory bucket in a bucket policy or an IAM identity-based policy. Then, you make the CreateSession API call on the bucket to obtain a session token. With the session token in your request header, you can make API requests to this operation. After the session token expires, you make another CreateSession API call to generate a new session token for use. Amazon Web Services CLI or SDKs create session and refresh the session token automatically to avoid service interruptions when a session expires. For more information about authorization, see CreateSession . If you enable x-amz-checksum-mode in the request and the object is encrypted with Amazon Web Services Key Management Service (Amazon Web Services KMS), you must also have the kms:GenerateDataKey and kms:Decrypt permissions in IAM identity-based policies and KMS key policies for the KMS key to retrieve the checksum of the object. Encryption Encryption request headers, like x-amz-server-side-encryption, should not be sent for HEAD requests if your object uses server-side encryption with Key Management Service (KMS) keys (SSE-KMS), dual-layer server-side encryption with Amazon Web Services KMS keys (DSSE-KMS), or server-side encryption with Amazon S3 managed encryption keys (SSE-S3). The x-amz-server-side-encryption header is used when you PUT an object to S3 and want to specify the encryption method. If you include this header in a HEAD request for an object that uses these types of keys, you’ll get an HTTP 400 Bad Request error. It's because the encryption method can't be changed when you retrieve the object. If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you retrieve the metadata from the object, you must use the following headers to provide the encryption key for the server to be able to retrieve the object's metadata. The headers are: x-amz-server-side-encryption-customer-algorithm x-amz-server-side-encryption-customer-key x-amz-server-side-encryption-customer-key-MD5 For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys) in the Amazon S3 User Guide. Directory bucket - For directory buckets, there are only two supported options for server-side encryption: SSE-S3 and SSE-KMS. SSE-C isn't supported. For more information, see Protecting data with server-side encryption in the Amazon S3 User Guide. Versioning If the current version of the object is a delete marker, Amazon S3 behaves as if the object was deleted and includes x-amz-delete-marker: true in the response. If the specified version is a delete marker, the response returns a 405 Method Not Allowed error and the Last-Modified: timestamp response header. Directory buckets - Delete marker is not supported for directory buckets. Directory buckets - S3 Versioning isn't enabled and supported for directory buckets. For this API operation, only the null value of the version ID is supported by directory buckets. You can only specify null to the versionId query parameter in the request. HTTP Host header syntax Directory buckets - The HTTP Host header syntax is Bucket-name.s3express-zone-id.region-code.amazonaws.com. For directory buckets, you must make requests for this API operation to the Zonal endpoint. These endpoints support virtual-hosted-style requests in the format https://amzn-s3-demo-bucket.s3express-zone-id.region-code.amazonaws.com/key-name . Path-style requests are not supported. For more information about endpoints in Availability Zones, see Regional and Zonal endpoints for directory buckets in Availability Zones in the Amazon S3 User Guide. For more information about endpoints in Local Zones, see Concepts for directory buckets in Local Zones in the Amazon S3 User Guide. The following actions are related to HeadObject: GetObject GetObjectAttributes You must URL encode any signed header values that contain spaces. For example, if your header value is my file.txt, containing two spaces after my, you must URL encode this value to my%20%20file.txt.

Sourcetype nonrec t = {
  1. deleteMarker : DeleteMarker.t option;
    (*

    Specifies whether the object retrieved was (true) or was not (false) a Delete Marker. If false, this response header does not appear in the response. This functionality is not supported for directory buckets.

    *)
  2. acceptRanges : AcceptRanges.t option;
    (*

    Indicates that a range of bytes was specified.

    *)
  3. expiration : Expiration.t option;
    (*

    If the object expiration is configured (see PutBucketLifecycleConfiguration ), the response includes this header. It includes the expiry-date and rule-id key-value pairs providing object expiration information. The value of the rule-id is URL-encoded. Object expiration information is not returned in directory buckets and this header returns the value "NotImplemented" in all responses for directory buckets.

    *)
  4. restore : Restore.t option;
    (*

    If the object is an archived object (an object whose storage class is GLACIER), the response includes this header if either the archive restoration is in progress (see RestoreObject or an archive copy is already restored. If an archive copy is already restored, the header value indicates when Amazon S3 is scheduled to delete the object copy. For example: x-amz-restore: ongoing-request="false", expiry-date="Fri, 21 Dec 2012 00:00:00 GMT" If the object restoration is in progress, the header returns the value ongoing-request="true". For more information about archiving objects, see Transitioning Objects: General Considerations. This functionality is not supported for directory buckets. Directory buckets only support EXPRESS_ONEZONE (the S3 Express One Zone storage class) in Availability Zones and ONEZONE_IA (the S3 One Zone-Infrequent Access storage class) in Dedicated Local Zones.

    *)
  5. archiveStatus : ArchiveStatus.t option;
    (*

    The archive state of the head object. This functionality is not supported for directory buckets.

    *)
  6. lastModified : LastModified.t option;
    (*

    Date and time when the object was last modified.

    *)
  7. contentLength : ContentLength.t option;
    (*

    Size of the body in bytes.

    *)
  8. checksumCRC32 : ChecksumCRC32.t option;
    (*

    The Base64 encoded, 32-bit CRC32 checksum of the object. This checksum is only present if the checksum was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it's a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

    *)
  9. checksumCRC32C : ChecksumCRC32C.t option;
    (*

    The Base64 encoded, 32-bit CRC32C checksum of the object. This checksum is only present if the checksum was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it's a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

    *)
  10. checksumCRC64NVME : ChecksumCRC64NVME.t option;
    (*

    The Base64 encoded, 64-bit CRC64NVME checksum of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

    *)
  11. checksumSHA1 : ChecksumSHA1.t option;
    (*

    The Base64 encoded, 160-bit SHA1 digest of the object. This checksum is only present if the checksum was uploaded with the object. When you use the API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it's a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

    *)
  12. checksumSHA256 : ChecksumSHA256.t option;
    (*

    The Base64 encoded, 256-bit SHA256 digest of the object. This checksum is only present if the checksum was uploaded with the object. When you use an API operation on an object that was uploaded using multipart uploads, this value may not be a direct checksum value of the full object. Instead, it's a calculation based on the checksum values of each individual part. For more information about how checksums are calculated with multipart uploads, see Checking object integrity in the Amazon S3 User Guide.

    *)
  13. checksumSHA512 : ChecksumSHA512.t option;
    (*

    The Base64 encoded, 512-bit SHA512 digest of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

    *)
  14. checksumMD5 : ChecksumMD5.t option;
    (*

    The Base64 encoded, 128-bit MD5 digest of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

    *)
  15. checksumXXHASH64 : ChecksumXXHASH64.t option;
    (*

    The Base64 encoded, 64-bit XXHASH64 checksum of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

    *)
  16. checksumXXHASH3 : ChecksumXXHASH3.t option;
    (*

    The Base64 encoded, 64-bit XXHASH3 checksum of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

    *)
  17. checksumXXHASH128 : ChecksumXXHASH128.t option;
    (*

    The Base64 encoded, 128-bit XXHASH128 checksum of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

    *)
  18. checksumType : ChecksumType.t option;
    (*

    The checksum type, which determines how part-level checksums are combined to create an object-level checksum for multipart objects. You can use this header response to verify that the checksum type that is received is the same checksum type that was specified in CreateMultipartUpload request. For more information, see Checking object integrity in the Amazon S3 User Guide.

    *)
  19. eTag : ETag.t option;
    (*

    An entity tag (ETag) is an opaque identifier assigned by a web server to a specific version of a resource found at a URL.

    *)
  20. missingMeta : MissingMeta.t option;
    (*

    This is set to the number of metadata entries not returned in x-amz-meta headers. This can happen if you create metadata using an API like SOAP that supports more flexible metadata than the REST API. For example, using SOAP, you can create metadata whose values are not legal HTTP headers. This functionality is not supported for directory buckets.

    *)
  21. versionId : ObjectVersionId.t option;
    (*

    Version ID of the object. This functionality is not supported for directory buckets.

    *)
  22. cacheControl : CacheControl.t option;
    (*

    Specifies caching behavior along the request/reply chain.

    *)
  23. contentDisposition : ContentDisposition.t option;
    (*

    Specifies presentational information for the object.

    *)
  24. contentEncoding : ContentEncoding.t option;
    (*

    Indicates what content encodings have been applied to the object and thus what decoding mechanisms must be applied to obtain the media-type referenced by the Content-Type header field.

    *)
  25. contentLanguage : ContentLanguage.t option;
    (*

    The language the content is in.

    *)
  26. contentType : ContentType.t option;
    (*

    A standard MIME type describing the format of the object data.

    *)
  27. contentRange : ContentRange.t option;
    (*

    The portion of the object returned in the response for a GET request.

    *)
  28. expires : Expires.t option;
    (*

    The date and time at which the object is no longer cacheable.

    *)
  29. websiteRedirectLocation : WebsiteRedirectLocation.t option;
    (*

    If the bucket is configured as a website, redirects requests for this object to another object in the same bucket or to an external URL. Amazon S3 stores the value of this header in the object metadata. This functionality is not supported for directory buckets.

    *)
  30. serverSideEncryption : ServerSideEncryption.t option;
    (*

    The server-side encryption algorithm used when you store this object in Amazon S3 or Amazon FSx. When accessing data stored in Amazon FSx file systems using S3 access points, the only valid server side encryption option is aws:fsx.

    *)
  31. metadata : Metadata.t option;
    (*

    A map of metadata to store with the object in S3.

    *)
  32. sSECustomerAlgorithm : SSECustomerAlgorithm.t option;
    (*

    If server-side encryption with a customer-provided encryption key was requested, the response will include this header to confirm the encryption algorithm that's used. This functionality is not supported for directory buckets.

    *)
  33. sSECustomerKeyMD5 : SSECustomerKeyMD5.t option;
    (*

    If server-side encryption with a customer-provided encryption key was requested, the response will include this header to provide the round-trip message integrity verification of the customer-provided encryption key. This functionality is not supported for directory buckets.

    *)
  34. sSEKMSKeyId : SSEKMSKeyId.t option;
    (*

    If present, indicates the ID of the KMS key that was used for object encryption.

    *)
  35. bucketKeyEnabled : BucketKeyEnabled.t option;
    (*

    Indicates whether the object uses an S3 Bucket Key for server-side encryption with Key Management Service (KMS) keys (SSE-KMS).

    *)
  36. storageClass : StorageClass.t option;
    (*

    Provides storage class information of the object. Amazon S3 returns this header for all objects except for S3 Standard storage class objects. For more information, see Storage Classes. Directory buckets - Directory buckets only support EXPRESS_ONEZONE (the S3 Express One Zone storage class) in Availability Zones and ONEZONE_IA (the S3 One Zone-Infrequent Access storage class) in Dedicated Local Zones.

    *)
  37. requestCharged : RequestCharged.t option;
  38. replicationStatus : ReplicationStatus.t option;
    (*

    Amazon S3 can return this header if your request involves a bucket that is either a source or a destination in a replication rule. In replication, you have a source bucket on which you configure replication and destination bucket or buckets where Amazon S3 stores object replicas. When you request an object (GetObject) or object metadata (HeadObject) from these buckets, Amazon S3 will return the x-amz-replication-status header in the response as follows: If requesting an object from the source bucket, Amazon S3 will return the x-amz-replication-status header if the object in your request is eligible for replication. For example, suppose that in your replication configuration, you specify object prefix TaxDocs requesting Amazon S3 to replicate objects with key prefix TaxDocs. Any objects you upload with this key name prefix, for example TaxDocs/document1.pdf, are eligible for replication. For any object request with this key name prefix, Amazon S3 will return the x-amz-replication-status header with value PENDING, COMPLETED or FAILED indicating object replication status. If requesting an object from a destination bucket, Amazon S3 will return the x-amz-replication-status header with value REPLICA if the object in your request is a replica that Amazon S3 created and there is no replica modification replication in progress. When replicating objects to multiple destination buckets, the x-amz-replication-status header acts differently. The header of the source object will only return a value of COMPLETED when replication is successful to all destinations. The header will remain at value PENDING until replication has completed for all destinations. If one or more destinations fails replication the header will return FAILED. For more information, see Replication. This functionality is not supported for directory buckets.

    *)
  39. partsCount : PartsCount.t option;
    (*

    The count of parts this object has. This value is only returned if you specify partNumber in your request and the object was uploaded as a multipart upload.

    *)
  40. tagCount : TagCount.t option;
    (*

    The number of tags, if any, on the object, when you have the relevant permission to read object tags. You can use GetObjectTagging to retrieve the tag set associated with an object. This functionality is not supported for directory buckets.

    *)
  41. objectLockMode : ObjectLockMode.t option;
    (*

    The Object Lock mode, if any, that's in effect for this object. This header is only returned if the requester has the s3:GetObjectRetention permission. For more information about S3 Object Lock, see Object Lock. This functionality is not supported for directory buckets.

    *)
  42. objectLockRetainUntilDate : ObjectLockRetainUntilDate.t option;
    (*

    The date and time when the Object Lock retention period expires. This header is only returned if the requester has the s3:GetObjectRetention permission. This functionality is not supported for directory buckets.

    *)
  43. objectLockLegalHoldStatus : ObjectLockLegalHoldStatus.t option;
    (*

    Specifies whether a legal hold is in effect for this object. This header is only returned if the requester has the s3:GetObjectLegalHold permission. This header is not returned if the specified version of this object has never had a legal hold applied. For more information about S3 Object Lock, see Object Lock. This functionality is not supported for directory buckets.

    *)
}
Sourcetype nonrec error = [
  1. | `NoSuchKey of NoSuchKey.t
  2. | `Unknown_operation_error of string * string option
]
Sourceval make : ?deleteMarker:??? -> ?acceptRanges:??? -> ?expiration:??? -> ?restore:??? -> ?archiveStatus:??? -> ?lastModified:??? -> ?contentLength:??? -> ?checksumCRC32:??? -> ?checksumCRC32C:??? -> ?checksumCRC64NVME:??? -> ?checksumSHA1:??? -> ?checksumSHA256:??? -> ?checksumSHA512:??? -> ?checksumMD5:??? -> ?checksumXXHASH64:??? -> ?checksumXXHASH3:??? -> ?checksumXXHASH128:??? -> ?checksumType:??? -> ?eTag:??? -> ?missingMeta:??? -> ?versionId:??? -> ?cacheControl:??? -> ?contentDisposition:??? -> ?contentEncoding:??? -> ?contentLanguage:??? -> ?contentType:??? -> ?contentRange:??? -> ?expires:??? -> ?websiteRedirectLocation:??? -> ?serverSideEncryption:??? -> ?metadata:??? -> ?sSECustomerAlgorithm:??? -> ?sSECustomerKeyMD5:??? -> ?sSEKMSKeyId:??? -> ?bucketKeyEnabled:??? -> ?storageClass:??? -> ?requestCharged:??? -> ?replicationStatus:??? -> ?partsCount:??? -> ?tagCount:??? -> ?objectLockMode:??? -> ?objectLockRetainUntilDate:??? -> ?objectLockLegalHoldStatus:??? -> unit -> t
Sourceval error_of_json : string -> Yojson.Safe.t -> [> `NoSuchKey of unit | `Unknown_operation_error of string * string option ]
Sourceval error_of_xml : string -> Awso.Xml.t -> [> `NoSuchKey of unit | `Unknown_operation_error of string * string option ]
Sourceval error_to_json : error -> Yojson.Safe.t
Sourceval of_header_and_body : ((Base.String.t, AcceptRanges.t) Awso.Import.List.Assoc.t * 'a) -> t
Sourceval to_value : t -> [> `Structure of (string * [> `Boolean of DeleteMarker.t | `Enum of string | `Integer of MissingMeta.t | `Long of ContentLength.t | `Map of ([> `String of MetadataKey.t ] * [> `String of MetadataValue.t ]) list | `String of AcceptRanges.t | `Timestamp of LastModified.t ]) list ]
Sourceval to_query : t -> Awso.Client.Query.t
Sourceval of_xml : Awso.Xml.t -> t
Sourceval of_string : string -> t
Sourceval of_json : Yojson.Safe.t -> t
Sourceval to_json : t -> Yojson.Safe.t