(CkPython) (using AWS Signature Version 2) Streaming Download to File

The main purpose of this example is to demonstrate how to use the older Signature Version 2 authentication w/ S3. It uses V2 authentication to download a file.

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

rest = chilkat.CkRest()

# Connect to the Amazon AWS REST server.
bTls = True
port = 443
bAutoReconnect = True
# The file is located in the bucket named "chilkat100", which becomes part of the domain:
success = rest.Connect("chilkat100.s3.amazonaws.com",port,bTls,bAutoReconnect)

# Provide AWS credentials for the REST call.
authAws = chilkat.CkAuthAws()
authAws.put_AccessKey("AWS_ACCESS_KEY")
authAws.put_SecretKey("AWS_SECRET_KEY")
authAws.put_ServiceName("s3")

# For AWS Signature Version 2, the following two properties need to be set:
authAws.put_SignatureVersion(2)
# See http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#ConstructingTheCanonicalizedResourceElement
authAws.put_CanonicalizedResourceV2("/chilkat100/starfish.jpg")

success = rest.SetAuthAws(authAws)

# Send the request to download the JPG.
success = rest.SendReqNoBody("GET","/starfish.jpg")
if (success != True):
    print(rest.lastErrorText())
    sys.exit()

# Read the response header.
responseStatusCode = rest.ReadResponseHeader()
if (responseStatusCode < 0):
    print(rest.lastErrorText())
    sys.exit()

print("Response status code = " + str(responseStatusCode))

# We expect a 200 response status if the JPG data is coming.
# Otherwise, we'll get a string response body with an error message(or no response body).
if (responseStatusCode == 200):

    bodyStream = chilkat.CkStream()

    # The stream's sink will be a file.
    bodyStream.put_SinkFile("qa_output/starfish.jpg")

    # Read the response body to the stream.  Given that we've
    # set the stream's sink to a file, it will stream directly
    # to the file.
    success = rest.ReadRespBodyStream(bodyStream,True)
    if (success != True):
        print(rest.lastErrorText())
        sys.exit()

    print("Successfully received the JPG file.")

else:
    errResponse = rest.readRespBodyString()
    if (rest.get_LastMethodSuccess() != True):
        print(rest.lastErrorText())
    else:
        print(errResponse)