Working a lot with .NET Core, using colon (‘:’) in appsettings is quite common. This allow a better separation of variables and, in the end, a better visibility.
Today, I’ve encountered an issue when trying to deploy my ASP.NET Core application on Kubernetes cluster:
##[error]The Deployment "XXXX" is invalid: spec.template.spec.containers[0].env[10].name: Invalid value: "PropertyName:PropertyValue": a valid environment variable name must consist of alphabetic characters, digits, '_', '-', or '.', and must not start with a digit (e.g. 'my.env-name', or 'MY_ENV.NAME', or 'MyEnvName1', regex used for validation is '[-._a-zA-Z][-._a-zA-Z0-9]*')
Ok, that’s gonna be funny 🙂
As I didn’t wanted to change my code to replace colon with something else, I searched on Internet and found the following Github issue: https://github.com/kubernetes/kubernetes/issues/53201
This allow me to find the good solution (as usual, explained in the documentation: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration/index?tabs=basicconfiguration&view=aspnetcore-3.1#environment-variables-configuration-provider). Indeed, the current workaround is just to replace ‘:’ with “__” (double underscore) when you define your environment variable:
env:
- name: PropertyName
value: "PropertyValue"
Pretty simple actually (when you know it ;))
Happy coding !