Multiple configuration files asp.net

This is useful in an ISP scenario. NET Provides reference documentation for general. NET Framework configuration. Securing ASP. NET application development. Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. The default JsonConfigurationProvider loads configuration in the following order:.

For example, by default:. If a configuration value must be guaranteed, see GetValue. Using the default configuration, the appsettings. Changes made to the appsettings. The preferred way to read related configuration values is using the options pattern.

For example, to read the following configuration values:. In the preceding code, by default, changes to the JSON configuration file after the app has started are read. The following code shows how to use ConfigurationBinder.

An alternative approach when using the options pattern is to bind the Position section and add it to the dependency injection service container. In the following code, PositionOptions is added to the service container with Configure and bound to configuration:. In the preceding code, changes to the JSON configuration file after the app has started are not read. To read changes after the app has started, use IOptionsSnapshot.

Related groups of registrations can be moved to an extension method to register services. For example, the configuration services are added to the following class:. The remaining services are registered in a similar class.

The following code uses the new extension methods to register the services:. Note: Each services. We recommended that apps follow the naming convention of creating extension methods in the Microsoft. DependencyInjection namespace. Creating extension methods in the Microsoft. DependencyInjection namespace:. By default , the user secrets configuration source is registered after the JSON configuration sources. Therefore, user secrets keys take precedence over keys in appsettings.

NET Core apps. Using the default configuration, the EnvironmentVariablesConfigurationProvider loads configuration from environment variable key-value pairs after reading appsettings.

Therefore, key values read from the environment override values read from appsettings. The : separator doesn't work with environment variable hierarchical keys on all platforms. The following setx commands can be used to set the environment keys and values on Windows. Unlike set , setx settings are persisted.

To test that the preceding commands override appsettings. Call AddEnvironmentVariables with a string to specify a prefix for environment variables:.

NET Core for host and app configuration , but not for user configuration. For more information on host and app configuration, see. NET Generic Host. Azure App Service application settings are:.

See Connection string prefixes for information on Azure database connection strings. Environment variable names reflect the structure of an appsettings. Each element in the hierarchy is separated by a double underscore preferable or a colon.

When the element structure includes an array, the array index should be treated as an additional element name in this path. Consider the following appsettings. Environment variables set in launchSettings. For example, the ASP. NET Core web templates generate a launchSettings. On Linux, the value of URL environment variables must be escaped so systemd can parse it.

Use the linux tool systemd-escape which yields httplocalhost The following code displays the environment variables and values on application startup, which can be helpful when debugging environment settings:. Using the default configuration, the CommandLineConfigurationProvider loads configuration from command-line argument key-value pairs after the following configuration sources:. By default , configuration values set on the command-line override configuration values set with all the other configuration providers.

Switch mappings allow key name replacement logic. Provide a dictionary of switch replacements to the AddCommandLine method.

When the switch mappings dictionary is used, the dictionary is checked for a key that matches the key provided by a command-line argument. If the command-line key is found in the dictionary, the dictionary value is passed back to set the key-value pair into the app's configuration. A switch mapping is required for any command-line key prefixed with a single dash -. For apps that use switch mappings, the call to CreateDefaultBuilder shouldn't pass arguments. The CreateDefaultBuilder method's AddCommandLine call doesn't include mapped switches, and there's no way to pass the switch-mapping dictionary to CreateDefaultBuilder.

The solution isn't to pass the arguments to CreateDefaultBuilder but instead to allow the ConfigurationBuilder method's AddCommandLine method to process both the arguments and the switch-mapping dictionary. Environment and command-line arguments can be set in Visual Studio from the launch profiles dialog:. The Configuration API reads hierarchical configuration data by flattening the hierarchical data with the use of a delimiter in the configuration keys.

The sample download contains the following appsettings. The following code from the sample download displays several of the configurations settings:. The preferred way to read hierarchical configuration data is using the options pattern. For more information, see Bind hierarchical configuration data in this document. GetSection and GetChildren methods are available to isolate sections and children of a section in the configuration data.

Configuration sources are read in the order that their configuration providers are specified. Order configuration providers in code to suit the priorities for the underlying configuration sources that the app requires. A common practice is to add the Command-line configuration provider last in a series of providers to allow command-line arguments to override configuration set by the other providers. The preceding sequence of providers is used in the default configuration.

The Configuration API has special processing rules for four connection string environment variables. These connection strings are involved in configuring Azure connection strings for the app environment.

Environment variables with the prefixes shown in the table are loaded into the app with the default configuration or when no prefix is supplied to AddEnvironmentVariables. When an environment variable is discovered and loaded into configuration with any of the four prefixes shown in the table:. FileConfigurationProvider is the base class for loading configuration from the file system. The following configuration providers derive from FileConfigurationProvider :.

The following code clears all the configuration providers and adds several configuration providers:. In the preceding code, settings in the MyIniConfig. The sample download contains the following MyIniConfig. You typically don't want a custom JSON file overriding values set in the Environment variables configuration provider and the Command-line configuration provider. Repeating elements that use the same element name work if the name attribute is used to distinguish the elements:.

The key is the file name. The value contains the file's contents. The Key-per-file configuration provider is used in Docker hosting scenarios. To activate key-per-file configuration, call the AddKeyPerFile extension method on an instance of ConfigurationBuilder.

The directoryPath to the files must be an absolute path. Call ConfigureAppConfiguration when building the host to specify the app's configuration:.

The MemoryConfigurationProvider uses an in-memory collection as configuration key-value pairs. The following code from the sample download displays the preceding configurations settings:. In the preceding code, config. AddInMemoryCollection Dict is added after the default configuration providers. For an example of ordering the configuration providers, see JSON configuration provider.

See Bind an array for another example using MemoryConfigurationProvider. Kestrel specific endpoint configuration overrides all cross-server endpoint configurations.

Cross-server endpoint configurations include:. When the preceding highlighted markup is used in an ASP. NET Core web app and the app is launched on the command line with the following cross-server endpoint configuration:. Kestrel binds to the endpoint configured specifically for Kestrel in the appsettings. In the preceding environment variable, Https is the name of the Kestrel specific endpoint.

The preceding appsettings. By default , environment variables using the Environment Variables configuration provider are read after appsettings. In the preceding code, if NumberKey isn't found in the configuration, the default value of 99 is used.

GetSection returns a configuration subsection with the specified subsection key. GetSection never returns null. If a matching section isn't found, an empty IConfigurationSection is returned.

When GetSection returns a matching section, Value isn't populated. A Key and Path are returned when the section exists. The following code calls IConfiguration. GetChildren and returns values for section2:subsection0 :.

The preceding code calls ConfigurationExtensions. Exists to verify the section exists:. The ConfigurationBinder. Bind supports binding arrays to objects using array indices in configuration keys. Any array format that exposes a numeric key segment is capable of array binding to a POCO class array.

To read the connection setting from the Config file, you have to use a single line of code:. AppSettings "ConnectionInfo". The appSettings element can contain a file attribute that points to an external file. I will change my web. Next, we can create the external file "externalSettings. If the external file is present, ASP. Net combines the appSettings values from web. Net will use the setting from the external file. This feature is useful when one keeps user-specific or environment-specific settings in the external file.

It is better to design web. This approach makes it easier to move around global web.