Topic 3, City Power & Light
Current environment
Architecture Overview
The company has a public website located at http://www.cpandl.com/. The site is a single-page web application that runs in Azure App Service on Linux. The website uses files stored in Azure Storage and cached in Azure Content Delivery Network (CDN) to serve static content.
API Management and Azure Function App functions are used to process and store data in Azure Database for PostgreSQL. API Management is used to broker communications to the Azure Function app functions for Logic app integration. Logic apps are used to orchestrate the data processing while Service Bus and Event Grid handle messaging and events.
The solution uses Application Insights, Azure Monitor, and Azure Key Vault.
Architecture diagram
The company has several applications and services that support their business. The company plans to implement serverless computing where possible. The overall architecture is shown below.

User authentication
The following steps detail the user authentication process:
The user selects Sign in in the website.
The browser redirects the user to the Azure Active Directory (Azure AD) sign in page.
The user signs in.
Azure AD redirects the user's session back to the web application. The URL includes an access token.
The web application calls an API and includes the access token in the authentication header. The application ID is sent as the audience ('aud') claim in the access token.
The back-end API validates the access token.
Requirements
Corporate website
Communications and content must be secured by using SSL.
Communications must use HTTPS.
Data must be replicated to a secondary region and three availability zones.
Data storage costs must be minimized.
Azure Database for PostgreSQL
The database connection string is stored in Azure Key Vault with the following attributes:
Azure Key Vault name: cpandlkeyvault
Secret name: PostgreSQLConn
Id: 80df3e46ffcd4f1cb187f79905e9a1e8
The connection information is updated frequently. The application must always use the latest information to connect to the database.
Azure Service Bus and Azure Event Grid
Azure Event Grid must use Azure Service Bus for queue-based load leveling.
Events in Azure Event Grid must be routed directly to Service Bus queues for use in buffering.
Events from Azure Service Bus and other Azure services must continue to be routed to Azure Event Grid for processing.
Security
All SSL certificates and credentials must be stored in Azure Key Vault.
File access must restrict access by IP, protocol, and Azure AD rights.
All user accounts and processes must receive only those privileges which are essential to perform their intended function.
Compliance
Auditing of the file updates and transfers must be enabled to comply with General Data Protection Regulation (GDPR). The file updates must be read-only, stored in the order in which they occurred, include only create, update, delete, and copy operations, and be retained for compliance reasons.
Issues
Corporate website
While testing the site, the following error message displays:
CryptographicException: The system cannot find the file specified.
Function app
You perform local testing for the RequestUserApproval function. The following error message displays:
'Timeout value of 00:10:00 exceeded by function: RequestUserApproval'
The same error message displays when you test the function in an Azure development environment when you run the following Kusto query:
FunctionAppLogs
| where FunctionName = = "RequestUserApproval"
Logic app
You test the Logic app in a development environment. The following error message displays:
'400 Bad Request'
Troubleshooting of the error shows an HttpTrigger action to call the RequestUserApproval function.
Code
Corporate website
Security.cs:

Function app
RequestUserApproval.cs:

Explanation

To create an internal load balancer, create a service manifest named internal-lb.yaml with the service type LoadBalancer and the azure-load-balancer-internal annotation as shown in the following example:
YAML:
apiVersion: v1
kind: Service
metadata:
name: internal-app
annotations:
service.beta.kubernetes.io/azure-load-balancer-internal: "true"
spec:
type: LoadBalancer
ports:
- port: 80
selector:
app: internal-app
References:
https://docs.microsoft.com/en-us/azure/aks/internal-lb

You can create an Azure Function with TrackAvailability() that will run periodically according to the configuration given in TimerTrigger function with your own business logic. The results of this test will be sent to your Application Insights resource, where you will be able to query for and alert on the availability results data. This allows you to create customized tests similar to what you can do via Availability Monitoring in the portal.
Customized tests will allow you to write more complex availability tests than is possible using the portal UI, monitor an app inside of your Azure VNET, change the endpoint address, or create an availability test even if this feature is not available in your region.
Reference:
https://docs.microsoft.com/en-us/azure/azure-monitor/app/availability-azure-functions

Explanation

Backup and Restore: Azure Backup
Scenario: The VM is critical and has not been backed up in the past. The VM must enable a quick restore from a 7-day snapshot to include in-place restore of disks in case of failure.
In-Place restore of disks in IaaS VMs is a feature of Azure Backup.
Performance: Accelerated Networking
Scenario: The VM shows high network latency, jitter, and high CPU utilization.
Accelerated networking enables single root I/O virtualization (SR-IOV) to a VM, greatly improving its networking performance. This high-performance path bypasses the host from the datapath, reducing latency, jitter, and CPU utilization, for use with the most demanding network workloads on supported VM types.
References:
https://azure.microsoft.com/en-us/blog/an-easy-way-to-bring-back-your-azure-vm-with-in-place-restore/