string Environment { get; }
Source
The current environment name. Read from command-line --environment
, "ASPNETCORE_ENVIRONMENT", or "DOTNET_ENVIRONMENT"; defaults to "Production" if none is set.
Defaults
DefaultEnvironmentProvider
Source
Default implementation of IEnvironmentProvider
that retrieves the environment from command-line host arguments or system environment variables. Command-line --environment
wins when supplied, otherwise it checks for "ASPNETCORE_ENVIRONMENT" first, then "DOTNET_ENVIRONMENT", and defaults to "Production" if neither is set. Can be overridden by passing a custom implementation to the StartupContext
, when building the host.
GetEnvironmentVariable
string? GetEnvironmentVariable(string name, string? defaultValue = null)
Gets the value of an environment variable from the system.
Parameters
-
nameThe exact environment variable name to query. -
defaultValueThe default value to return if the environment variable is unset.
Returns
The environment variable value, an empty string when explicitly set empty, or the provided default if the variable is unset.
Remarks
Use GetEnvironmentVariable
when callers need the provider's centralized lookup and unset-value defaulting behavior. Use Environment
or IsDevelopment
for the active application environment, and prefer direct System.Environment
access only for low-level infrastructure code. Passing a null or empty name
follows System.Environment.GetEnvironmentVariable(string)
semantics. Do not log returned values unless the variable is known to be non-sensitive, and do not trim or alter casing unless the caller intentionally wants to change the platform-specific value.
ResolveEnvironmentArgument
string? ResolveEnvironmentArgument(IReadOnlyList<string> args)
Resolves the effective command-line environment value from host arguments.
Parameters
-
argsCommand-line arguments supplied to the host startup pipeline.
Returns
The last valid command-line environment value, or null
when none is supplied.
Remarks
Recognizes split and inline forms such as --environment Development
and --environment=Development
. Blank, switch-like, or assignment-shaped split values are ignored, and the last valid command-line value wins to match Microsoft configuration duplicate-key behavior. Returns null
when the arguments do not contain a valid command-line environment value.
Environment
IsDevelopment
bool IsDevelopment { get; }
Source
True if the current environment is "Development".
NoHostModule
Source
A basic implementation of IAppSurfaceHostModule
that does nothing. This is useful for providing implementations of apps that do not require a module.
Remarks
Use NoHostModule
only when no part of the application expects module-provided services, dependency registrations, middleware, endpoints, or host configuration. It is safe for minimal hosts that rely entirely on framework defaults. Create a real IAppSurfaceHostModule
when the app needs service registration, dependency wiring, or host lifecycle hooks.
ConfigureServices
void ConfigureServices(StartupContext context, IServiceCollection services)
Configures services for the module. This implementation is empty.
Parameters
-
contextThe startup context. -
servicesThe service collection.
Remarks
No services are added. Callers that expect module-owned services must not use NoHostModule
.
RegisterDependentModules
void RegisterDependentModules(ModuleDependencyBuilder builder)
Registers dependent modules. This implementation is empty.
Parameters
-
builderThe module dependency builder.
Remarks
No dependencies are declared. Create a concrete module when startup ordering or dependency modules matter.
ConfigureHostBeforeServices
void ConfigureHostBeforeServices(StartupContext context, IHostBuilder builder)
Configures the host before services are registered. This implementation is empty.
Parameters
-
contextThe startup context. -
builderThe host builder.
Remarks
No host configuration is applied before service registration.
ConfigureHostAfterServices
void ConfigureHostAfterServices(StartupContext context, IHostBuilder builder)
Configures the host after services are registered. This implementation is empty.
Parameters
-
contextThe startup context. -
builderThe host builder.
Remarks
No host configuration is applied after service registration.
InternalServicesModule
SourceInternal Services Registration