User-defined Header (SDK for Python)

Updated on 2024-11-26 GMT+08:00

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Function

When calling an API, you can configure user-defined headers to meet specific needs. The SDK will automatically calculate the signature for the specified headers if needed.

Method:

You can add the specified headers in extensionHeaders in the dictionary format.

Restrictions

The mapping between OBS regions and endpoints must comply with what is listed in Regions and Endpoints.

Code Examples

This example configures user-defined headers to use the single-connection bandwidth throttling function for downloading object objectname from bucket examplebucket at a limited rate.

    
     
       
       from obs import ObsClient
import os
import traceback

# Obtain an AK and SK pair using environment variables or import the AK and SK pair in other ways. Using hard coding may result in leakage.
# Obtain an AK and SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
ak = os.getenv("AccessKeyID")
sk = os.getenv("SecretAccessKey")
# (Optional) If you use a temporary AK and SK pair and a security token to access OBS, obtain them from environment variables.
# security_token = os.getenv("SecurityToken")
# Set server to the endpoint corresponding to the bucket. CN-Hong Kong is used here as an example. Replace it with the one in use.
server = "https://obs.ap-southeast-1.myhuaweicloud.com" 

# Create an obsClient instance.
# If you use a temporary AK and SK pair and a security token to access OBS, you must specify security_token when creating an instance.
obsClient = ObsClient(access_key_id=ak, secret_access_key=sk, server=server)
try:
    bucketName = "examplebucket"
    objectKey = "objectname"
    # Configure the download rate limit by specifying x-obs-traffic-limit, in bits. The value range is from 819200 (100 KB) to 838860800 (100 MB). 819200 is used as an example.
    extensionHeaders = {'x-obs-traffic-limit': 819200}
    # Specify the full path (localfile as an example) to which objects are downloaded. The full path contains the local file name.
    downloadPath = 'localfile'
    # Download the object at a limited rate.
    resp = obsClient.getObject(bucketName, objectKey, downloadPath, extensionHeaders=extensionHeaders)

    # If status code 2xx is returned, the API was called successfully. Otherwise, the call failed.
    if resp.status < 300:
        print('Get Object Succeeded')
        print('requestId:', resp.requestId)
        print('url:', resp.body.url)
    else:
        print('Get Object Failed')
        print('requestId:', resp.requestId)
        print('errorCode:', resp.errorCode)
        print('errorMessage:', resp.errorMessage)
except:
    print('Get Object Failed')
    print(traceback.format_exc())

      

    
   

This example configures a user-defined header to implement the upload callback.

    
     
       
       from obs import ObsClient
import os
import traceback
from urllib.parse import quote
import base64
import json

# Obtain an AK and SK pair using environment variables or import the AK and SK pair in other ways. Using hard coding may result in leakage.
# Obtain an AK and SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
ak = os.getenv("AccessKeyID")
sk = os.getenv("SecretAccessKey")
# (Optional) If you use a temporary AK and SK pair and a security token to access OBS, obtain them from environment variables.
# security_token = os.getenv("SecurityToken")
# Set server to the endpoint corresponding to the bucket. CN-Hong Kong is used here as an example. Replace it with the one in use.
server = "https://obs.ap-southeast-1.myhuaweicloud.com"

# Create an obsClient instance.
# If you use a temporary AK and SK pair and a security token to access OBS, you must specify security_token when creating an instance.
obsClient = ObsClient(access_key_id=ak, secret_access_key=sk, server=server)
try:
    # Specify a protocol.
    protocol = 'http://'

    # Specify the callback address. If the URL contains any special characters or full-width characters, they must be URL-encoded using quote(str).
    callbackUrl1 = protocol + quote("www.example.com/callback1")
    callbackUrl2 = protocol + quote ("www.example.com/full-width-characters?key=object-name-in-full-width-characters")
    # (Optional) Specify the value of the host header carried in the callback request. If this parameter is not specified, the value of host parsed from callbackUrl is used.
    callbackHost = 'www.example.com'
    # Specify the body of the callback request.
    callbackBody = 'key=$(key)&override=$(override)&size=$(size)&bucket=$(bucket)&etag=$(etag)'
    # Configure the upload callback.
    callBackPolicy = {"callbackBody": callbackBody, "callbackUrl": callbackUrl1 + ';' + callbackUrl2,
                      "callbackHost": callbackHost}

    # Configure the custom headers by specifying extensionHeaders. The input parameters are in the dictionary format.
    # Convert callBackPolicy to a JSON string and then to  binary using json.dumps().encode(). Then, encode the results using Base64 (base64.b64encode()) and convert the encoded data which is in binary mode to a string using str(b'str', "utf-8").
    extensionHeaders = {'x-obs-callback': str(base64.b64encode(json.dumps(callBackPolicy).encode()), "utf-8")}

    bucketName = 'your-bucketName'
    objectKey = 'example.txt'
    content = 'Hello OBS'
    # Upload the text and perform the upload callback.
    resp = obsClient.putContent(bucketName, objectKey, content, extensionHeaders=extensionHeaders)

    # If status code 2xx is returned, the API was called successfully. Otherwise, the call failed.
    if resp.status < 300:
        print('Put Content Succeeded')
        print('requestId:', resp.requestId)
        print('etag:', resp.body.etag)
    else:
        print('Put Content Failed')
        print('requestId:', resp.requestId)
        print('errorCode:', resp.errorCode)
        print('errorMessage:', resp.errorMessage)
except:
    print('Put Content Failed')
    print(traceback.format_exc())

      

    
   

This example changes the expiration time of an object using a user-defined header.

     
      
        
        from obs import ObsClient
import os
import traceback

# Obtain an AK and SK pair using environment variables or import the AK and SK pair in other ways. Using hard coding may result in leakage.
# Obtain an AK and SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
ak = os.getenv("AccessKeyID")
sk = os.getenv("SecretAccessKey")
# (Optional) If you use a temporary AK and SK pair and a security token to access OBS, obtain them from environment variables.
# security_token = os.getenv("SecurityToken")
# Set server to the endpoint corresponding to the bucket. CN-Hong Kong is used here as an example. Replace it with the one in use.
server = "https://obs.ap-southeast-1.myhuaweicloud.com" 

# Create an obsClient instance.
# If you use a temporary AK and SK pair and a security token to access OBS, you must specify security_token when creating an instance.
obsClient = ObsClient(access_key_id=ak, secret_access_key=sk, server=server)
try:
    bucketName = "examplebucket"
    objectKey = "objectname"
    # x-obs-expires indicates how many days after the last modification the object expires. This example configures 3 days.
    extensionHeaders = {'x-obs-expires': 3}
    # Configure the object metadata.
    resp = obsClient.setObjectMetadata(bucketName, objectKey, extensionHeaders=extensionHeaders)

    # If status code 2xx is returned, the API was called successfully. Otherwise, the call failed.
    if resp.status < 300:
        print('Set Object Metadata Succeeded')
        print('requestId:', resp.requestId)
    else:
        print('Set Object Metadata Failed')
        print('requestId:', resp.requestId)
        print('errorCode:', resp.errorCode)
        print('errorMessage:', resp.errorMessage)
except:
    print('Set Object Metadata Failed')
    print(traceback.format_exc())

       

     
    

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