Lua

Azure Storage: CORS Preflight Blob Request

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Azure Storage Blob Service REST API: Sample code to send a CORS pre-flight blob request. Lua

local chilkat = require("chilkat")

-- Azure Blob Service Example: CORS Preflight Blob Request
-- See also: https://msdn.microsoft.com/en-us/library/azure/dn535599.aspx

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

local rest = chilkat.Rest.new()

-- Connect to the Azure Storage Blob Service
local bTls = true
local port = 443
local bAutoReconnect = true
-- In this example, the storage account name is "chilkat".
local success = rest:connect("chilkat.blob.core.windows.net", port, bTls, bAutoReconnect)
if not success then
    print(rest.last_error_text)
    return
end

-- Provide Azure Cloud credentials for the REST call.
local azAuth = chilkat.AuthAzureStorage.new()
azAuth.access_key = "AZURE_ACCESS_KEY"
-- The account name used here should match the 1st part of the domain passed in the call to Connect (above).
azAuth.account = "chilkat"
azAuth.scheme = "SharedKey"
azAuth.service = "Blob"
-- This causes the "x-ms-version: 2021-08-06" header to be automatically added.
azAuth.xms_version = "2021-08-06"
success = rest:set_auth_azure_storage(azAuth)

-- Note: The application does not need to explicitly set the following
-- headers: x-ms-date, Authorization.  These headers
-- are automatically set by Chilkat.

-- The preflight blob request requires the following two HTTP headers.
-- The Origin is the domain from which the actual request will be issued.
success = rest:add_header("Origin", "www.contoso.com")
-- The Access-Control-Request-Method is the HTTP method (such as GET, POST, PUT, etc.) of the actual request.
success = rest:add_header("Access-Control-Request-Method", "PUT")

-- The expected response is a 202 response status code with no response body.
-- The name of the container or blob resource in this example is "test". (Replace "test" with your container name.)
local responseStr = rest:full_request_no_body("OPTIONS", "/test")
if not rest.last_method_success then
    print(rest.last_error_text)
    return
end

-- When successful, the Azure Storage service will respond with a 200 response code,
-- with no response body.

-- If CORS is not enabled or no matching rule is found for the request,
-- then a 403 status code is returned, with the following status text:
-- "CORS not enabled or no matching rule found for this request."
if rest.response_status_code ~= 200 then
    -- Examine the request/response to see what happened.
    print("response status code = " .. rest.response_status_code)
    print("response status text = " .. rest.response_status_text)
    print("response header: " .. rest.response_header)
    print("response body (if any): " .. responseStr)
    print("---")
    print("LastRequestStartLine: " .. rest.last_request_start_line)
    print("LastRequestHeader: " .. rest.last_request_header)
    return
end

print("Success: Preflight Blob Request is accepted.")