User-defined Header (SDK for Python)

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.

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/eu/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. EU-Dublin is used here as an example. Replace it with the one in use.
server = "https://obs.eu-west-101.myhuaweicloud.eu" 

# 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 user-defined headers 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/eu/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. EU-Dublin is used here as an example. Replace it with the one in use.
server = "https://obs.eu-west-101.myhuaweicloud.eu" 

# 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 special characters or fullwidth characters, the URL must be encoded using quote(str).
    callbackUrl1 = protocol + quote("www.example.com/callback1")
    callbackUrl2 = protocol + quote ("www.example.com/fullwidth characters?key=fullwidth 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/eu/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. EU-Dublin is used here as an example. Replace it with the one in use.
server = "https://obs.eu-west-101.myhuaweicloud.eu" 

# 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())

         

       

     
    