How to deploy dotnetcore/react -au Individual to Azure - sqlite

Question

If you install the dotnetcore3 SDK and create the dotnetcore/react project, it compiles and runs fine. Modifications to use external identity providers are straightforward and work as documented. You will need to add packages for the providers you wish to support, such as Microsoft.AspNetCore.Authentication.MicrosoftAccount.
At this point you might try dotnet publish but the resultant package produces the following (truncated) stack trace:
info: IdentityServer4.Startup[0]
Starting IdentityServer4 version 3.0.0.0
crit: Microsoft.AspNetCore.Hosting.Diagnostics[6]
Application startup exception
System.InvalidOperationException: Key type not specified.
at Microsoft.AspNetCore.ApiAuthorization.IdentityServer.ConfigureSigningCredentials.LoadKey()
at Microsoft.AspNetCore.ApiAuthorization.IdentityServer.ConfigureSigningCredentials.Configure(ApiAuthorizationOptions options)
Service Worker
The template is set up with a service worker. This is a jolly nuisance while debugging our configuration so turn it off by commenting out registerServiceWorker(); in ClientApp/src/index.js and if you've already run the app then you will need to flush your cache to dislodge it.
Certificate
A certificate is required. The project template uses OIDC implemented with IdentityServer4, and therefore requires a PFX. On Windows you can create one of these using CertReq. It would be poor security practice to add this to the project so I made the PFX file sibling to the project folder. The registration in appSettings.json looks like this:
"IdentityServer": {
"Key": {
"Type": "File",
"FilePath": "../cert-name.pfx",
"Password": "cert-password"
}
},
Secrets
dotnet add secret is strictly a development mode thing. We are expected to manually transcribe all the secrets to Azure environment variables and modify the program to include them in its configuration loading process.
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureAppConfiguration((hostingContext, config) =>
{
config.AddEnvironmentVariables();
})
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
The names in dotnet secrets are full of colons. You'll also need to escape these colons as double underscores for cross platform compatibility.
Since dotnet add secret isn't exactly the most convenient tool ever it occurs to me that it might be less bother to just use environment variables all the way through.
Core version madness
Silly me trying to use the LTS version (3.1).
Creating a Classic CI pipeline from the Azure portal, it is impossible to select dotnet core 3.1 because it's not in the list. The list does contain LTS and Latest but both of these selections produce validation errors when you try to finalise the deployment. Choosing 3.0 allows finalisation which results in the deployment running but although it manages to publish to the Web App on Azure, the Web App is set to dotnet core 3.0 and since the project specifies 3.1 it won't start.
You can manually change this in the Web App Configuration blade in the Azure portal, but it just gets mangled on every deployment. Changing the project to use 3.0 and compatible packages seems to work.
Am I using the tools incorrectly, or is the Azure CICD set up really crap?
npm
And now it starts but can't find 'npm'. Installing npm using ssh looks like this (it's already root so sudo is not involved)
curl -sL https://deb.nodesource.com/setup_13.x | bash
apt-get install -y nodejs
and this seems to work but it doesn't survive a restart of the Web App (presumably it is installed outside /home)
Everything works without auth
If I deploy a project created with dotnet new react without the -au Individual qualifier, it works perfectly. The site loads, the web APIs are called, the data returns etc.
What's the difference? There are a couple.
IdentityServer4
SQLite
Generation of the SQLite database
Rummaging in the .csproj I find this
<PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="3.0.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.0.0">
and this is the first thing used in ConfigureServices
services.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlite(Configuration.GetConnectionString("DefaultConnection")));
but this doesn't trigger the exception. That occurs later when IdentityServer is created. Further up the stack trace we find this:
Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore
.MigrationsEndPointMiddleware.Invoke(HttpContext context)
from which I conclude that EF uses Node to do migration, at least for SQLite.
I don't think it would help to add npm to package.json because that would just bundle it for delivery to the browser. It appears that npm is required at the server for the migration process.
But Node and npm are simply not part of the dotnet core Web App stack.
One suggestion (via Reddit) is to use a Node stack Web App and deploy a self-contained build of the dotnet core server code. This is my next port of call. In the spirit of solving one problem at a time I shall first learn to do self-contained build deployment with a minimal Core/React project (no auth).
This almost works. Using SSH I was able to run the app and it started without throwing any errors but listened on port 5000 rather than 8080 which is where it needs to be if you want it surfaced on port 80 on the public interface.
On the Node stack, the startup script is unsurprisingly configured to to launch a Node app, and it barfs before it gets to the startup command you supply. Because it's a Node startup script it also doesn't set up ASPNETCORE_URLS=http://*:$PORT which is required to make the core project serve on port 8080.

Answer 1

Taking a step back, npm is a development thing. Why would anyone deliberately introduce it as a production dependency? That would be crazy, it would create mayhem.
The key word in that question is "deliberately". What if it weren't deliberate? How could you do it accidentally? Well, you could write a script to gather all your environment variables and plonk them into Azure, and this might capture ASPNETCORE_ENVIRONMENT=Development
Lo and behold, there it was. Deleting it restarts the app and HURRAH! no more demands for NPM. Looks like the stack isn't broken after all. Which makes me a happy camper since I didn't want to give up CICD.
This could also be defined in appsettings.json.
The important takeaway is that if you see demands for npm after deployment to Azure, your app is trying to run in development mode in a production environment.