# Uploading Objects - POST

#### Functions

Uploading an object adds it to a bucket. This requires users to have the write operation.

The name of each object in a bucket must be unique.

With versioning not enabled, if an object to be uploaded has the same name as an existing object in the bucket, the newly uploaded object will overwrite the existing one. To protect data from being corrupted during transmission, you can add the Content-MD5 parameter in the form field. After receiving the request, OBS will perform an MD5 consistency check. If the two MD5 values are inconsistent, the system returns an error message. You can also specify the value of the x-obs-acl parameter to configure an access control policy for the object.

You can also upload an object using the POST method.

For a single upload, the size of the object to be uploaded ranges [0, 5 GB]. To upload a file greater than 5 GB, see Operations on Multipart Upload.

This operation supports server-side encryption.

#### Differences Between PUT and POST Methods

Parameters are passed through the request header if the PUT method is used to upload objects; if the POST method is used to upload objects, parameters are passed through the form field in the message body.

With the PUT method, you need to specify the object name in the URL, but object name is not required with the POST method, which uses the bucket domain name as the URL. The request lines of the two methods are as follows:

    PUT /ObjectName HTTP/1.1

    POST / HTTP/1.1

For details about PUT upload, see Uploading Objects - PUT.

#### Versioning

If versioning is enabled for a bucket, the system automatically generates a unique version ID for the requested object in this bucket and returns the version ID in response header x-obs-version-id. If versioning is suspended for a bucket, the version ID of the requested object in this bucket is null. For details about the versioning statuses of a bucket, see Configuring Versioning for a Bucket.

#### Request Syntax

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    POST / HTTP/1.1
    Host: bucketname.obs.region.example.com
    User-Agent: browser_data
    Accept: file_types
    Accept-Language: Regions
    Accept-Encoding: encoding
    Accept-Charset: character_set
    Keep-Alive: 300
    Connection: keep-alive
    Content-Type: multipart/form-data; boundary=9431149156168
    Content-Length: length

    --9431149156168
    Content-Disposition: form-data; name="key"

    acl
    --9431149156168
    Content-Disposition: form-data; name="success_action_redirect"

    success_redirect
    --9431149156168
    Content-Disposition: form-data; name="content-Type"

    content_type
    --9431149156168
    Content-Disposition: form-data; name="x-obs-meta-uuid"

    uuid
    --9431149156168
    Content-Disposition: form-data; name="x-obs-meta-tag"

    metadata
    --9431149156168
    Content-Disposition: form-data; name="AccessKeyId"

    access-key-id
    --9431149156168
    Content-Disposition: form-data; name="policy"

    encoded_policy
    --9431149156168
    Content-Disposition: form-data; name="signature"

    signature=
    --9431149156168
    Content-Disposition: form-data; name="file"; filename="MyFilename"
    Content-Type: image/jpeg

    file_content
    --9431149156168
    Content-Disposition: form-data; name="submit"

    Upload to OBS
    --9431149156168--

#### Request Parameters

This request contains no parameter.

#### Request Headers

This request uses common headers. For details, see Table 3.

If you want to get CORS configuration information, you must use the headers in Table 1.

Table 1 Request headers for obtaining CORS configuration
Header | Description | Mandatory
--- | --- | ---
Origin | Origin of the cross-domain request specified by the pre-request. Generally, it is a domain name. Type: string | Yes
Access-Control-Request-Headers | Indicates the HTTP headers of a request. The request can use multiple HTTP headers. Type: string | No

#### Request Elements

This request uses form elements. Table 2 describes the form elements.

Table 2 Form elements
Parameter | Description | Mandatory
--- | --- | ---
file | Indicates the content of the object to be uploaded. Type: binary content or text Constraint: This parameter must be the last parameter in a form. Otherwise, parameters after this parameter will be all discarded. Additionally, each request contains only one file parameter. | Yes
key | Indicates the name of the object to be created. Type: string | Yes
AccessKeyId | Access key ID (AK) of the requester. Type: string Constraint: This parameter is mandatory if there is security policy parameter policy or signature in the request. | Yes when the constraint is met.
policy | Indicates the security policy in the request. For details about the policy format, see the policy format in Authentication of Signature Carried in the Table Uploaded Through a Browser. Type: string Constraint: This parameter is mandatory if the bucket provides the AccessKeyId (or signature). | Yes when the constraint is met.
signature | Indicates a signature string calculated based on StringToSign. Type: string Constraint: This parameter is mandatory if the bucket provides the AccessKeyId (or policy). | Yes when the constraint is met.
token | Specifies the AK, signature, and security policy of the request initiator. The priority of a token is higher than that of a specified AK, the request signature, and the security policy of the request initiator. Type: string Example: In HTML: <input type= "text" name="token" value="ak:signature:policy" /> | No

x-obs-acl

When creating an object, you can add this message header to set the permission control policy for the object. The predefined common policies are as follows: private, public-read, public-read-write, public-read-delivered, and public-read-write-delivered.

Type: string

An example is provided as follows:

In POLICY: {"acl": "public-read" }

In HTML: <input type="text" name="acl" value="public-read" />

No

x-obs-grant-read | When creating an object, you can use this header to authorize all users in an account the permission to read objects and obtain object metadata. Type: string An example is provided as follows: In POLICY: {'grant-read': 'id=domainId1' }, In HTML: <input type="text" name="grant-read" value="id=domainId1" /> | No
x-obs-grant-read-acp | When creating an object, you can use this header to authorize all users in an account the permission to obtain the object ACL. Type: string An example is provided as follows: In POLICY: {"grant-read-acp": "id=domainId1" }, In HTML: <input type="text" name="grant-read-acp" value="id=domainId1" /> | No
x-obs-grant-write-acp | When creating an object, you can use this header to authorize all users in an account the permission to write the object ACL. Type: string An example is provided as follows: In POLICY: {"grant-write-acp": "id=domainId1" }, In HTML: <input type="text" name="grant-write-acp" value="id=domainId1" /> | No

x-obs-grant-full-control

When creating an object, you can use this header to authorize all users in an account the permission to read the object, obtain the object metadata, obtain the object ACL, and write the object ACL.

Type: string

An example is provided as follows:

In POLICY: {"grant-full-control": "id=domainId1" },

In HTML: <input type="text" name="grant-full-control" value="id=domainId1" />

No

x-obs-storage-class

When creating an object, you can use this header to specify the storage class for the object. If you do not use this header, the object storage class is the default storage class of the bucket.

Type: string

Note: There are three storage classes: STANDARD (Standard storage class), WARM (Warm storage class), and COLD (Cold storage class). Therefore, this parameter value can be STANDARD, WARM, or COLD. These values are case sensitive.

An example is provided as follows:

In POLICY: {"storage-class": "STANDARD" },

In HTML: <input type="text" name="x-obs-storage-class" value="STANDARD" />

No

Cache-Control, Content-Type, Content-Disposition, Content-Encoding Expires | Standard HTTP headers. OBS records those headers. If you download the object or send the HEAD Object request, those parameter values are returned. Type: string An example is provided as follows: In POLICY: ["starts-with", "$Content-Type", "text/"], In HTML: <input type="text" name="content-type" value="text/plain" /> | No

success_action_redirect

Indicates the address (URL) to which a successfully responded request is redirected.

- If the value is valid and the request is successful, OBS returns status code 303. Location contains success_action_redirect as well as the bucket name, object name, and object ETag.
- If this parameter is invalid, OBS ignores this parameter. The response code is 204, and the Location is the object address.

Type: string.

An example is provided as follows:

In POLICY: {"success_action_redirect": "http://123458.com"},

In HTML: <input type="text" name="success_action_redirect" value="http://123458.com" />

No

x-obs-meta-*

Indicates user-defined metadata. When creating an object, you can use this header or a header starting with x-obs-meta- to define object metadata in an HTTP request. Custom metadata will be returned in the response header when you retrieve or query the metadata of the object.

Type: string

An example is provided as follows:

In POLICY: {" x-obs-meta-test ": " test metadata " },

In HTML: <input type="text" name=" x-obs-meta-test " value=" test metadata " />

No

success_action_status

Indicates the status code returned after the request is successfully received. Possible values are 200, 201, and 204.

- If this parameter is set to 200 or 204, the body in the OBS response message is empty.
- If this parameter is set to 201, the OBS response message contains an XML document that describes the response to the request.
- If the value is not set or if it is set to an invalid value, the OBS returns an empty document with a 204 status code.

Type: string

An example is provided as follows:

In POLICY: ["starts-with", "$success_action_status", ""],

In HTML: <input type="text" name="success_action_status" value="200" />

No

x-obs-website-redirect-location

If a bucket is configured with the static website hosting function, it will redirect requests for this object to another object in the same bucket or to an external URL. OBS stores the value of this header in the object metadata.

Default value: none

Constraint: The value must be prefixed by a slash (/), http://, or https://. The length of the value cannot exceed 2 KB.

No

x-obs-server-side-encryption | Indicates that SSE-KMS is used. Type: string Example: x-obs-server-side-encryption:kms | No. This header is required when SSE-KMS is used.

x-obs-server-side-encryption-kms-key-id

Master key ID. This header is used in SSE-KMS mode. If the customer does not provide the master key ID, the default master key ID will be used.

Type: string

The following two formats are supported:

1. regionID:domainID:key/key_id

2. key_id

regionID is the ID of the region to which the key belongs. domainID is the account ID of the tenant to which the key belongs. key_id is the key ID created in KMS.

Example:

1. x-obs-server-side-encryption-kms-key-id: region:domainiddomainiddomainiddoma0001:key/4f1cd4de-ab64-4807-920a-47fc42e7f0d0

2. x-obs-server-side-encryption-kms-key-id:4f1cd4de-ab64-4807-920a-47fc42e7f0d0

No

x-obs-server-side-encryption-customer-algorithm | Encryption algorithm. The header is used in SSE-C mode. Type: string Example: x-obs-server-side-encryption-customer-algorithm:AES256 Constraint: This header must be used together with x-obs-server-side-encryption-customer-key and x-obs-server-side-encryption-customer-key-MD5. | No. This header is required when SSE-C is used.

x-obs-server-side-encryption-customer-key

A key used to encrypt objects. The header is used in SSE-C mode. This key is used to encrypt objects.

Type: string

Example: x-obs-server-side-encryption-customer-key:K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=

Constraint: This header is a Base64-encoded 256-bit key and must be used together with x-obs-server-side-encryption-customer-algorithm and x-obs-server-side-encryption-customer-key-MD5.

No. This header is required when SSE-C is used.

x-obs-server-side-encryption-customer-key-MD5

Indicates the MD5 value of a key used to encrypt objects. The header is used in SSE-C mode. The MD5 value is used to check whether any error occurs during the transmission of the key.

Type: string

Example: x-obs-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ==

Constraint: This header is a Base64-encoded 128-bit MD5 value and must be used together with x-obs-server-side-encryption-customer-algorithm and x-obs-server-side-encryption-customer-key.

No. This header is required when SSE-C is used.

x-obs-expires | Indicates the expiration time of an object, in days. An object will be automatically deleted once it expires (calculated from the last modification time of the object). Type: integer Example: x-obs-expires:3 | No

#### Response Syntax

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    HTTP/1.1 status_code
    Content-Type: application/xml
    Location: location
    Date: date
    ETag: etag

#### Response Headers

The response to the request uses common headers. For details, see Table 1.

In addition to the common response headers, the following message headers may also be used. For details, see Table 3.

Table 3 Additional response header parameters
Header | Description
--- | ---
x-obs-version-id | Object version ID. If versioning is enabled for the bucket, the object version ID will be returned. A string null will be returned if the bucket housing the object has versioning suspended. Type: string
Access-Control-Allow-Origin | Indicates that the origin is included in the response if the origin in the request meets the CORS configuration requirements when CORS is configured for buckets. Type: string
Access-Control-Allow-Headers | Indicates that the headers are included in the response if headers in the request meet the CORS configuration requirements when CORS is configured for buckets. Type: string
Access-Control-Max-Age | Indicates MaxAgeSeconds in the CORS configuration of the server when CORS is configured for buckets. Type: integer
Access-Control-Allow-Methods | Indicates that methods in the rule are included in the response if Access-Control-Request-Method in the request meets the CORS configuration requirements when CORS is configured for buckets. Type: string Possible values are GET, PUT, HEAD, POST, and DELETE.
Access-Control-Expose-Headers | Value of ExposeHeader in the CORS configuration of a server when CORS is configured for buckets. Type: string
x-obs-server-side-encryption | This header is included in a response if SSE-KMS is used. Type: string Example: x-obs-server-side-encryption:kms

x-obs-server-side-encryption-kms-key-id

Indicates the master key ID. This header is included in a response if SSE-KMS is used.

Type: string

Format: regionID:domainID:key/key_id

regionID is the ID of the region to which the key belongs. domainID is the account ID of the tenant to which the key belongs. key_id is the key ID used in this encryption.

Example: x-obs-server-side-encryption-kms-key-id:region:domainiddomainiddomainiddoma0001:key/4f1cd4de-ab64-4807-920a-47fc42e7f0d0

x-obs-server-side-encryption-customer-algorithm | Indicates an encryption algorithm. This header is included in a response if SSE-C is used. Type: string Example: x-obs-server-side-encryption-customer-algorithm:AES256
x-obs-server-side-encryption-customer-key-MD5 | Indicates the MD5 value of a key used to encrypt objects. This header is included in a response if SSE-C is used. Type: string Example: x-obs-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ==

#### Response Elements

This response involves no elements.

#### Error Responses

No special error responses are returned. For details about error responses, see Table 2.

#### Sample Request 1

Common POST upload

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    POST / HTTP/1.1
    Date: WED, 01 Jul 2015 04:15:23 GMT
    Host: examplebucket.obs.region.example.com
    Content-Type: multipart/form-data; boundary=7db143f50da2
    Content-Length: 2424
    Origin: www.example.com
    Access-Control-Request-Headers:acc_header_1

    --7db143f50da2
    Content-Disposition: form-data; name="key"

    object01
    --7db143f50da2
    Content-Disposition: form-data; name="acl"

    public-read
    --7db143f50da2
    Content-Disposition: form-data; name="content-type"

    text/plain
    --7db143f50da2
    Content-Disposition: form-data; name="expires"

    WED, 01 Jul 2015 04:16:15 GMT
    --7db143f50da2
    Content-Disposition: form-data; name="AccessKeyId"

    14RZT432N80TGDF2Y2G2
    --7db143f50da2
    Content-Disposition: form-data; name="policy"

    ew0KICAiZXhaaXJhdGlvbiI6ICIyMDE1LTA3LTAxVDEyOjAwOjAwLjAwMFoiLA0KICAiY29uZGl0aW9ucyI6IFsNCiAgICB7ImJ1Y2tldCI6ICJleG1hcGxlYnVja2V0IiB9LA0KICAgIHsiYWNsIjogInB1YmxpYy1yZWFkIiB9LA0KICAgIHsiRXhaaXJlcyI6ICIxMDAwIiB9LA0KICAgIFsiZXEiLCAiJGtleSIsICJvYmplY3QwMSJdLA0KICAgIFsic3RhcnRzLXdpdGgiLCAiJENvbnRlbnQtVHlwZSIsICJ0ZXh0LyJdLA0KICBdDQp9DQo=
    --7db143f50da2
    Content-Disposition: form-data; name="signature"

    Vk6rwO0Nq09BLhvNSIYwSJTRQ+k=
    --7db143f50da2
    Content-Disposition: form-data; name="file"; filename="C:\Testtools\UpLoadFiles\object\1024Bytes.txt"
    Content-Type: text/plain

    01234567890
    --7db143f50da2
    Content-Disposition: form-data; name="submit"

    Upload
    --7db143f50da2--

#### Sample Response 1

After CORS is configured for a bucket, the response contains the Access-Control-* information.

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    HTTP/1.1 204 No Content
    x-obs-request-id: 90E2BA00C26C00000133B442A90063FD
    x-obs-id-2: OTBFMkJBMDBDMjZDMDAwMDAxMzNCNDQyQTkwMDYzRkRBQUFBQUFBQWJiYmJiYmJi
    Access-Control-Allow-Origin: www.example.com
    Access-Control-Allow-Methods: POST,GET,HEAD,PUT
    Access-Control-Allow-Headers: acc_header_01
    Access-Control-Max-Age: 100
    Access-Control-Expose-Headers: exp_header_01
    Content-Type: text/xml
    Location: http://examplebucket.obs.region.example.com/object01
    Date: WED, 01 Jul 2015 04:15:23 GMT
    ETag: "ab7abb0da4bca5323ab6119bb5dcd296"

#### Sample Request 2

Upload an object with the x-obs-acl, storage class, and redirection header fields carried in the request message.

Before encoding, the policy content is as follows:

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    {
        "expiration":"2018-07-17T04:54:35Z",
        "conditions":[
            {
                "content-type":"text/plain"
            },
            {
                "x-obs-storage-class":"WARM"
            },
            {
                "success_action_redirect":"http://www.example.com"
            },
            {
                "x-obs-acl":"public-read"
            },
            [
                "starts-with",
                "$bucket",
                ""
            ],
            [
                "starts-with",
                "$key",
                ""
            ]
        ]
    }

Sample request:

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    POST / HTTP/1.1
    Host: examplebucket.obs.region.example.com
    Accept-Encoding: identity
    Content-Length: 947
    Content-Type: multipart/form-data; boundary=9431149156168
    User-Agent: OBS/Test

    --9431149156168
    Content-Disposition: form-data; name="x-obs-acl"

    public-read
    --9431149156168
    Content-Disposition: form-data; name="AccessKeyId"

    H4IPJX0TQTHTHEBQQCEC
    --9431149156168
    Content-Disposition: form-data; name="key"

    my-obs-object-key-demo
    --9431149156168
    Content-Disposition: form-data; name="signature"

    WNwv8P1ZiWdqPQqjXeLmAfzPDAI=
    --9431149156168
    Content-Disposition: form-data; name="policy"

    eyJleHBpcmF0aW9uIjoiMjAxOC0wNy0xN1QwODozNDoyM1oiLCAiY29uZGl0aW9ucyI6W3siY29udGVudC10eXBlIjoidGV4dC9wbGFpbiJ9LHsieC1vYnMtYWNsIjoicHVibGljLXJlYWQifSxbInN0YXJ0cy13aXRoIiwgIiRidWNrZXQiLCAiIl0sWyJzdGFydHMtd2l0aCIsICIka2V5IiwgIiJdXX0=
    --9431149156168
    Content-Disposition: form-data; name="content-type"

    text/plain
    --9431149156168
    Content-Disposition: form-data; name="file"; filename="myfile"
    Content-Type: text/plain

    c2c6cd0f-898e-11e8-aab6-e567c91fb541
    52b8e8a0-8481-4696-96f3-910635215a78

    --9431149156168--

#### Sample Response 2

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    HTTP/1.1 204 No Content
    Server: OBS
    Location: http://examplebucket.obs.region.example.com/my-obs-object-key-demo
    ETag: "17a83fc8d431273405bd266114b7e034"
    x-obs-request-id: 5DEB00000164A728A7C7F4E032214CFA
    x-obs-id-2: 32AAAUJAIAABAAAQAAEAABAAAQAAEAABCSwj2PcBE0YcoLHUDO7GSj+rVByzjflA
    Date: Tue, 17 Jul 2018 07:33:36 GMT

Parent topic: Operations on Objects