Azure Queues are a great way to provide reliable, cloud-based messaging between applications. There are multiple ways in which you can interact with Queues, including through the use of RESTful API calls. In this lab, you will have the opportunity to read from and write to an Azure Queue using the Azure Queue service REST API.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Save a list of the current messages to a file.
- Set up some environment variables to aid in generating a signature. For the
storage_accountandaccess_key, provide the actual storage account name and access key. One way to obtain these is to log in to the Azure portal. The access key can be found by clicking the storage account, then clickingAccess Keys:
storage_account=${your storage account name} access_key=${your storage account access key} queue_name=incoming-items request_date=$(TZ=GMT date "+%a, %d %h %Y %H:%M:%S %Z") resource="/${storage_account}/${queue_name}/messages" request_method="GET" headers="x-ms-date:$request_date"- Generate a signature and Authorization header:
string_to_sign="${request_method}nnnn${headers}n${resource}" hex_key="$(echo -n $access_key | base64 -d -w0 | xxd -p -c256)" signature=$(printf "$string_to_sign" | openssl dgst -sha256 -mac HMAC -macopt "hexkey:$hex_key" -binary | base64 -w0) authorization_header="SharedKey $storage_account:$signature"- Make a request to peek the current messages in the queue, redirecting the output to a file:
curl -s -X $request_method -H "x-ms-date:$request_date" -H "Authorization:$authorization_header" "https://${storage_account}.queue.core.windows.net/${queue_name}/messages?peekonly=true&numofmessages=32" > /home/cloud_user/messages.txt- Check the contents of the file to see the messages:
cat /home/cloud_user/messages.txtYou should see some XML representing one existing message.
- Set up some environment variables to aid in generating a signature. For the
- Manually add the lost data to the queue.
- Set up some environment variables to aid in generating a signature.
request_date=$(TZ=GMT date "+%a, %d %h %Y %H:%M:%S %Z") resource="/${storage_account}/${queue_name}/messages" request_method="POST" content_type="application/x-www-form-urlencoded; charset=utf-8" storage_service_version="2018-11-09" headers="x-ms-date:$request_datenx-ms-version:$storage_service_version" message="Item 4489: Coin Collection" message_base64=$(echo $message | base64) message_xml="<QueueMessage><MessageText>$message_base64</MessageText></QueueMessage>" message_length=${#message_xml}- Generate a signature and Authorization header.
string_to_sign="${request_method}nnn$message_lengthnn$content_typennnnnnn${headers}n${resource}nmessagettl:-1" hex_key="$(echo -n $access_key | base64 -d -w0 | xxd -p -c256)" signature=$(printf "$string_to_sign" | openssl dgst -sha256 -mac HMAC -macopt "hexkey:$hex_key" -binary | base64 -w0) authorization_header="SharedKey $storage_account:$signature"- Make a request to peek the current messages in the queue, redirecting the output to a file.
curl -X $request_method -H "x-ms-date:$request_date" -H "x-ms-version:$storage_service_version" -H "Content-Type:$content_type" -H "Authorization:$authorization_header" --data "$message_xml" "https://${storage_account}.queue.core.windows.net/${queue_name}/messages?messagettl=-1"- If you wish, you can check the Queue in Azure Portal to verify that your new message appears.
