Configuration and environments

The rule

Settings come from appsettings.json, then appsettings.<environment>.json, then environment variables (Section__Key). The base file holds safe defaults for anywhere; the environment files hold what's only true for that environment.

The Lambda template has no appsettings files or environments. Its startup builds configuration from environment variables alone, so the same keys are set as ConnectionStrings__MovieReviews and Database__SeedSampleData, and the defaults live in Startup.

Settings that exist today:

Steps

1. Put the safe default in appsettings.json. If the default is "off" or empty, still write the key so people can find it.
2. Override it only in the environment files that need a different value.
3. Read a single value with configuration.GetValue<T>("Section:Key"); read a group into a settings class with a SectionName constant and a FromConfiguration(IConfiguration) method, like AuthenticationSettings in a solution with authentication.
4. Document the key in docs/RUN.md if someone running the app might change it.
5. Tests override settings in memory (integration-tests), never by editing the JSON.

Don't

• Put secrets, passwords or tokens in any appsettings*.json file. Use environment variables or user secrets.
• Check IsEnvironment("local") for behaviour that should be a setting. Add a setting instead.
• Read Environment.GetEnvironmentVariable directly. Go through IConfiguration.

Check

dotnet test