Setting up custom config when hosting an api in a testconatiner using a private k8s image.

[Anchita]

Hi there, I am wondering if someone can point me to useful documentation or examples around my use-case please. I'm trying to host a web api in a kubernetes pod for testing. I'm using test containers instead of WebApplicationFactory as this test is meant to be more end to end. I am able to wire up dependencies such as queues, database. However, I don't seem to be able to get appsettings working using bind mounts. For example, I'd like to set some flags in the config to disabled for testing purposes. Do we have any examples around this that I can refer to? So this is the test flow
Set up containers for dependencies
Pull private image for the api (netcore)
Use custom appsettings to set up test flag used for development - stuck here !?
Host the api in a container

Thanks,
Anchita

[HofmeisterAn]

I'm using test containers instead of WebApplicationFactory

You don't have to choose one or the other, you can use both and test your application in-process. I'll leave a few examples and articles below.

Use custom appsettings to set up test flag used for development - stuck here !?

Avoid mounting files or directories into the container, as this won't work in every container runtime environment (see our best practices). To configure an ASP.NET application, you can do one of the following:

1. Copy the AppSettings file (or other files) into the container.
2. Use environment variables to override the AppSettings configuration (out-of-process).
3. Or use WebApplicationFactory to override the configuration directly (see Set Redis connection string as an example).

---

• Out-of-process example (it's using env vars, but you can also copy the config file).
• In-process example (using WebApplicationFactory).
• Testcontainers with ASP.NET Core Apps.
• Testcontainers Best Practices for .NET Integration Testing.

[Anchita]

Thank you, I'll try to follow these examples. I already have integration tests using WebApplicationFactory where I set up the required config in a CustomTestHost using the ConfigureHostConfiguration. Now, the requirement is to add some more tests which host the api in a pod to make them more prod like. Its just that I haven't yet found an equivalent of ConfigureHostConfiguration in testcontainers.

[HofmeisterAn]

to make them more prod like

I'd probably go with env vars, since that's usually how it's configured in prod.

[Anchita]

Thank you, that worked