In this lab, we use Azure CLI to create multiple slots in an Azure Function App Service, then deploy two different versions of an app to each slot. Once that is finished, we run the app in each slot, swap the two slots, and then run the apps again. Finally we verify that the output has swapped.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Log In to the Azure Portal
Log in to the Azure Portal using the username and password supplied by the lab.
- Open a browser.
- Navigate to the provided Azure Portal URL.
- Use the supplied username and password to authenticate.
- Remote into the Windows VM
Starting in the Azure dashboard, perform the following tasks:
- Open the navigation menu in the upper-left of the Portal.
- Click on All resources.
Wait for all the resources to appear.
In the list, click on the lab-VM resource.
Wait for the VM overview page to open. On that page, make note of the public IP address.
Using a remote desktop client, connect to the IP address of the VM. Log in using the credentials provided on the lab page.
Accept the certificate if asked to do so.
Wait for the desktop to load and stabilize. If the server manager opens, click ‘No’ for network sharing and close it.
- Install Azure Functions Core Tools
Open PowerShell ISE as an administrator. Open a new script window. Paste the following into the editor window (not the blue pane).
choco install nodejs-lts -y --force npm i -g azure-functions-core-tools@3 --unsafe-perm true code --install-extension ms-vscode.csharp code --install-extension ms-vscode.azurecli code --install-extension ms-azuretools.vscode-azurefunctions code --install-extension ms-vscode.azure-account code --install-extension ms-azuretools.vscode-azurestorage code --install-extension ms-vscode.powershellRun the script by pressing
F5or the play button.Wait a few minutes for it to complete.
Close the PowerShell ISE window.
- Open the Project in Visual Studio Code
Open an administrative command prompt. Change the directory using the following command:
cd codeslotsNow open the project in visual studio code with the following command:
code .Wait for Visual Studio Code to open the solution.
On the toast message about detecting an Azure Functions project being found in the folder, press the Yes button.
On the toast message about "There are unresolved dependencies…", Click the Restore button.
- Log In to Azure with AZ CLI
In Visual Studio Code, open the file
scripts.ps1.Highlight the line with the code:
az loginNow press
F8to run the single line of code.Internet Explorer will open. One tab will open with a login form (there will be several other nag screens we need to avoid or close). Log in with the Azure credentials given by the lab environment, the same ones used to log in to the Portal.
When the login is complete, Internet Explorer will say so, and the
az logincommnand will return in the Visual Studio Code terminal.- Retrieve the Name of the Function App and Resource Group
Execute the following lines of code in the
scripts.ps1file:$funcappname = $(az functionapp list --query "[0].name" -o tsv) $funcappname $group = $(az group list --query "[0].name" -o tsv) $group- Create the Staging Slot and Production Slot
Execute the following lines of code in the
scripts.ps1file:az functionapp deployment slot create --name $funcappname -g $group --slot production az functionapp deployment slot create --name $funcappname -g $group --slot stagingNote that the production slot is already created, and the one line has essentially no effect and is present just for example.
- Build and Deploy the Production Application
Execute the following lines of code in the
scripts.ps1file:# modify code (A) dotnet clean dotnet build func azure functionapp publish $funcappname --force --csharp- Update the Function
Open the
MyHttpFunction.csfile. Modify the following line of code from:return (ActionResult)new OkObjectResult($"A");To:
return (ActionResult)new OkObjectResult($"B");Then execute the following lines of code in the
scripts.ps1file:# modify code (B) dotnet clean dotnet build func azure functionapp publish $funcappname --slot staging --force --csharp- Run the Production and Staging Apps and Examine Output
In the Azure Portal, navigate to the Function App Service.
Starting in the Azure dashboard perform the following tasks:
- Open the navigation menu in the upper-left of the Portal.
- Click All resources.
Wait for all the resources to appear.
In the list, click the app service that has a name that starts with fa-. This will open the overview page of the function app service.
Click on the MyHttpFunction in the production slot near the top of the function apps navigation tree, not in the Slots section of this tree. When the function opens, press the Run button. The test panel will open and show "A" in the output panel.
Now click on the MyHttpFunction in the staging slot. When the function opens, press the Run button. The test panel will open and show "B" in the output panel.
- Swap Slots, Run Functions, and Check Output
Back in Visual Studio Code, run the following line of the
scripts.ps1file:az functionapp deployment slot swap -g $group -n $funcappname --slot staging --target-slot productionBack in the Azure Portal, click on the MyHttpFunction in the production slot near the top of the function apps navigation tree, not in the Slots section of this tree. When the function opens, press the Run button. The test panel will open and show "B" in the output panel.
Now click on the MyHttpFunction in the staging slot. When the function opens, press the Run button. The test panel will open and show "A" in the output panel.
The functions in the two slots have been swapped.
