/// <summary>
/// Adds and configures a fallback strategy for if the main strategy or remote authentication
/// fail to resolve a tenant.
/// </summary>
public static FinbuckleMultiTenantBuilder WithFallbackStrategy(this FinbuckleMultiTenantBuilder builder,
string identifier)
{
if (identifier == null)
{
throw new ArgumentNullException(nameof(identifier));
}
builder.Services.TryAddSingleton <FallbackStrategy>(sp => new FallbackStrategy(identifier));
return(builder);
}
/// <summary>
/// Adds and configures a ClaimsStrategy to the application.
/// </summary>
/// <remarks>
/// The claims strategy does not rely on TenantContext. Therefore, it is not necessary to
/// register the tenant context here. The only thing it relies on is a tenant claim name and this
/// is registered via a TenantConfiguration object which is injected into the TenantConfigurations
/// object. The TenantConfigurations object will handle duplicates in case app settings are also
/// registered and have a tenant claim name value.
/// </remarks>
/// <param name="builder"></param>
/// <param name="tenantClaimName">The name of the claim holding the tenant id.</param>
/// <returns></returns>
public static FinbuckleMultiTenantBuilder WithClaimsStrategy(this FinbuckleMultiTenantBuilder builder, string tenantClaimName)
{
// add the claim name as a manual configuration
builder.Services.AddSingleton <ITenantConfiguration>(new TenantConfiguration()
{
Key = Constants.TenantClaimName, Value = tenantClaimName
});
// add the configuration wrapper
builder.Services.AddTenantConfigurations();
// register the strategy with the built in finbuckly custom strategy
builder.WithStrategy <ClaimsStrategy>(ServiceLifetime.Scoped);
return(builder);
}
/// <summary>
/// Adds a HttpRemoteSTore to the application.
/// </summary>
/// <param name="endpointTemplate">The endpoint URI template.</param>
/// <param name="clientConfig">An action to configure the underlying HttpClient.</param>
public static FinbuckleMultiTenantBuilder WithHttpRemoteStore(this FinbuckleMultiTenantBuilder builder,
string endpointTemplate,
Action <IHttpClientBuilder> clientConfig)
{
var httpClientBuilder = builder.Services.AddHttpClient(typeof(HttpRemoteStoreClient).FullName);
if (clientConfig != null)
{
clientConfig(httpClientBuilder);
}
builder.Services.TryAddSingleton <HttpRemoteStoreClient>();
return(builder.WithStore <HttpRemoteStore>(ServiceLifetime.Singleton, endpointTemplate));
}
/// <summary>
/// Adds and configures a RouteStrategy to the application.
/// </summary>
/// <param name="tenantParam">The name of the route parameter used to determine the tenant identifier.</param>
/// <param name="configRoutes">Delegate to configure the routes.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder WithRouteStrategy(this FinbuckleMultiTenantBuilder builder,
string tenantParam,
Action <IRouteBuilder> configRoutes)
{
if (string.IsNullOrWhiteSpace(tenantParam))
{
throw new ArgumentException("Invalud value for \"tenantParam\"", nameof(tenantParam));
}
if (configRoutes == null)
{
throw new ArgumentNullException(nameof(configRoutes));
}
return(builder.WithStrategy <RouteStrategy>(ServiceLifetime.Singleton, new object[] { tenantParam, configRoutes }));
}
/// <summary>
/// Adds and configures a FormStrategy to the application with a configuration section configuration which reloads with changes.
/// </summary>
/// <remarks>
/// The form strategy does not rely on TenantContext. Therefore, it is not necessary to
/// register the tenant context here. The only thing it relies on is a FormStrategyConfiguration
/// object. This object is either added as a parameter or injected via IOptionsSnapshot.
/// </remarks>
/// <param name="builder"></param>
/// <param name="formStrategyConfiguration">The configuration section defining the form strategy configuration and resolved with IOptionsSnapshot<></param>
/// <returns></returns>
public static FinbuckleMultiTenantBuilder WithFormStrategy(this FinbuckleMultiTenantBuilder builder, IConfigurationSection configurationSection)
{
// validate the configuration section
var formStrategyConfiguration = new FormStrategyConfiguration();
configurationSection.Bind(formStrategyConfiguration);
ValidateFormStrategyConfiguration(formStrategyConfiguration);
// register configuration so it will reload with changes
builder.Services.Configure <FormStrategyConfiguration>(configurationSection);
// register the strategy with the built in finbuckly custom strategy
builder.WithStrategy <FormStrategy>(ServiceLifetime.Scoped);
return(builder);
}
private static void BypassSessionPrincipalValidation <TTenantInfo>(
FinbuckleMultiTenantBuilder <TTenantInfo> builder)
where TTenantInfo : class, ITenantInfo, new()
{
builder.Services.ConfigureAll <CookieAuthenticationOptions>(options =>
{
var origOnValidatePrincipal = options.Events.OnValidatePrincipal;
options.Events.OnValidatePrincipal = async context =>
{
// Skip if bypass set (e.g. ClaimStrategy in effect)
if (context.HttpContext.Items.Keys.Contains(
$"{Constants.TenantToken}__bypass_validate_principal__"))
{
return;
}
if (origOnValidatePrincipal != null)
{
await origOnValidatePrincipal(context);
}
};
});
}
/// <summary>
/// Configures core functionality for per-tenant authentication.
/// </summary>
/// <param name="builder">MultiTenantBuilder instance.</param>
/// <param name="config">Authentication options config</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithPerTenantAuthenticationCore <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder, Action <MultiTenantAuthenticationOptions>?config =
null)
where TTenantInfo : class, ITenantInfo, new()
{
config ??= _ => { };
builder.Services.Configure(config);
// We need to "decorate" IAuthenticationService so callbacks so that
// remote authentication can get the tenant from the authentication
// properties in the state parameter.
if (builder.Services.All(s => s.ServiceType != typeof(IAuthenticationService)))
{
throw new MultiTenantException(
"WithPerTenantAuthenticationCore() must be called after AddAuthentication() in ConfigureServices.");
}
builder.Services.DecorateService <IAuthenticationService, MultiTenantAuthenticationService <TTenantInfo> >();
// We need to "decorate" IAuthenticationScheme provider.
builder.Services.DecorateService <IAuthenticationSchemeProvider, MultiTenantAuthenticationSchemeProvider>();
return(builder);
}
/// <summary>
/// Adds and configures a SessionStrategy to the application.
/// </summary>
/// <param name="builder">MultiTenantBuilder instance.</param>
/// <param name="tenantKey">The session key to use.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithSessionStrategy <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder, string tenantKey)
where TTenantInfo : class, ITenantInfo, new()
=> builder.WithStrategy <SessionStrategy>(ServiceLifetime.Singleton, tenantKey);
/// <summary>
/// Adds and configures a SessionStrategy to the application.
/// </summary>
/// <param name="builder">MultiTenantBuilder instance.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithSessionStrategy <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder)
where TTenantInfo : class, ITenantInfo, new()
=> builder.WithStrategy <SessionStrategy>(ServiceLifetime.Singleton, Constants.TenantToken);
/// <summary> /// Adds and configures a BasePathStrategy to the application. /// </summary> /// <returns>The same MultiTenantBuilder passed into the method.></returns> public static FinbuckleMultiTenantBuilder WithBasePathStrategy(this FinbuckleMultiTenantBuilder builder) => builder.WithStrategy <BasePathStrategy>(ServiceLifetime.Singleton);
/// <summary>
/// Configures conventional functionality for per-tenant authentication.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithPerTenantAuthenticationConventions <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder, Action <MultiTenantAuthenticationOptions> config = null)
where TTenantInfo : class, ITenantInfo, new()
{
// Set events to set and validate tenant for each cookie based authentication principal.
builder.Services.ConfigureAll <CookieAuthenticationOptions>(options =>
{
// Validate that claimed tenant matches current tenant.
var origOnValidatePrincipal = options.Events.OnValidatePrincipal;
options.Events.OnValidatePrincipal = async context =>
{
await origOnValidatePrincipal(context);
// Skip if no principal or bypass set
if (context.Principal == null || context.HttpContext.Items.Keys.Contains($"{Constants.TenantToken}__bypass_validate_principle__"))
{
return;
}
var currentTenant = context.HttpContext.GetMultiTenantContext <TTenantInfo>()?.TenantInfo?.Identifier;
// If no current tenant and no tenant claim then OK
if (currentTenant == null && !context.Principal.Claims.Any(c => c.Type == Constants.TenantToken))
{
return;
}
// Does a tenant claim for the principal match the current tenant?
if (!context.Principal.Claims.Where(c => c.Type == Constants.TenantToken && String.Equals(c.Value, currentTenant, StringComparison.OrdinalIgnoreCase)).Any())
{
context.RejectPrincipal();
}
};
// Set the tenant claim when signing in.
var origOnSigningIn = options.Events.OnSigningIn;
options.Events.OnSigningIn = async context =>
{
await origOnSigningIn(context);
if (context.Principal == null)
{
return;
}
var identity = (ClaimsIdentity)context.Principal.Identity;
var currentTenant = context.HttpContext.GetMultiTenantContext <TTenantInfo>()?.TenantInfo?.Identifier;
if (currentTenant != null &&
!identity.Claims.Where(c => c.Type == Constants.TenantToken && c.Value == currentTenant).Any())
{
identity.AddClaim(new Claim(Constants.TenantToken, currentTenant));
}
};
});
// Set per-tenant cookie options by convention.
builder.WithPerTenantOptions <CookieAuthenticationOptions>((options, tc) =>
{
var d = (dynamic)tc;
try { options.LoginPath = ((string)d.CookieLoginPath).Replace(Constants.TenantToken, tc.Identifier); } catch { }
try { options.LogoutPath = ((string)d.CookieLogoutPath).Replace(Constants.TenantToken, tc.Identifier); } catch { }
try { options.AccessDeniedPath = ((string)d.CookieAccessDeniedPath).Replace(Constants.TenantToken, tc.Identifier); } catch { }
});
// Set per-tenant OpenIdConnect options by convention.
builder.WithPerTenantOptions <OpenIdConnectOptions>((options, tc) =>
{
var d = (dynamic)tc;
try { options.Authority = ((string)d.OpenIdConnectAuthority).Replace(Constants.TenantToken, tc.Identifier); } catch { }
try { options.ClientId = ((string)d.OpenIdConnectClientId).Replace(Constants.TenantToken, tc.Identifier); } catch { }
try { options.ClientSecret = ((string)d.OpenIdConnectClientSecret).Replace(Constants.TenantToken, tc.Identifier); } catch { }
});
var challengeSchemeProp = typeof(TTenantInfo).GetProperty("ChallengeScheme");
if (challengeSchemeProp != null && challengeSchemeProp.PropertyType == typeof(string))
{
builder.WithPerTenantOptions <AuthenticationOptions>((options, tc)
=> options.DefaultChallengeScheme = (string)challengeSchemeProp.GetValue(tc) ?? options.DefaultChallengeScheme);
}
return(builder);
}
// #endif
/// <summary>
/// Adds and configures a HostStrategy with template "__tenant__.*" to the application.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithHostStrategy <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder)
where TTenantInfo : class, ITenantInfo, new()
=> builder.WithHostStrategy($"{Constants.TenantToken}.*");
/// <summary>
/// Adds and configures a ClaimStrategy for claim name "__tenant__" to the application. Uses the default authentication handler scheme.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithClaimStrategy <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder) where TTenantInfo : class, ITenantInfo, new()
{
return(builder.WithClaimStrategy(Constants.TenantToken));
}
/// <summary>
/// Adds and configures a BasePathStrategy to the application.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.></returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithBasePathStrategy <TTenantInfo>(this FinbuckleMultiTenantBuilder <TTenantInfo> builder)
where TTenantInfo : class, ITenantInfo, new()
=> builder.WithStrategy <BasePathStrategy>(ServiceLifetime.Singleton);
/// <summary>
/// Adds and configures a Header to the application.
/// </summary>
/// <param name="builder">MultiTenantBuilder instance.</param>
/// <param name="tenantKey">The template for determining the tenant identifier in the host.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithHeaderStrategy <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder, string tenantKey)
where TTenantInfo : class, ITenantInfo, new()
{
return(builder.WithStrategy <HeaderStrategy>(ServiceLifetime.Singleton, tenantKey));
}
/// <summary>
/// Adds and configures InMemoryStore to the application using the provided ConfigurationSeciont.
/// </summary>
/// <param name="config">The ConfigurationSection which contains the InMemoryStore configuartion settings.</param>
/// <param name="ignoreCase">Whether the store should ignore case.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder WithInMemoryStore(this FinbuckleMultiTenantBuilder builder,
IConfigurationSection configurationSection,
bool ignoreCase)
=> builder.WithInMemoryStore(o => configurationSection.Bind(o), ignoreCase);
/// <summary>
/// Adds and configures a case-insensitive InMemoryStore to the application using the provided action.
/// </summary>
/// <param name="config">A delegate or lambda for configuring the tenant.</param>
/// <param name="ignoreCase">Whether the store should ignore case.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder WithInMemoryStore(this FinbuckleMultiTenantBuilder builder,
Action <InMemoryStoreOptions> config)
=> builder.WithInMemoryStore(config, true);
/// <summary>
/// Adds an empty InMemoryStore to the application.
/// </summary>
/// <param name="ignoreCase">Whether the store should ignore case.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder WithInMemoryStore(this FinbuckleMultiTenantBuilder builder,
bool ignoreCase)
=> builder.WithInMemoryStore(_ => { }, ignoreCase);
/// <summary> /// Adds an empty, case-insensitive InMemoryStore to the application. /// </summary> /// <returns>The same MultiTenantBuilder passed into the method.</returns> public static FinbuckleMultiTenantBuilder WithInMemoryStore(this FinbuckleMultiTenantBuilder builder) => builder.WithInMemoryStore(true);
/// <summary>
/// Adds and configures a HostStrategy with template "\_\_tenant\_\_.*" to the application.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder WithHostStrategy(this FinbuckleMultiTenantBuilder builder)
=> builder.WithHostStrategy("__tenant__.*");
/// <summary>
/// Adds and configures a RemoteAuthenticationCallbackStrategy to the application.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithRemoteAuthenticationCallbackStrategy <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder)
where TTenantInfo : class, ITenantInfo, new()
{
return(builder.WithStrategy <RemoteAuthenticationCallbackStrategy>(ServiceLifetime.Singleton));
}
/// <summary>
/// Adds an EFCore based multitenant store to the application. Will also add the database context service unless it is already added.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithEFCoreStore <TEFCoreStoreDbContext, TTenantInfo>(this FinbuckleMultiTenantBuilder <TTenantInfo> builder)
where TEFCoreStoreDbContext : EFCoreStoreDbContext <TTenantInfo>
where TTenantInfo : class, ITenantInfo, new()
{
builder.Services.AddDbContext <TEFCoreStoreDbContext>(); // Note, will not override existing context if already added.
return(builder.WithStore <EFCoreStore <TEFCoreStoreDbContext, TTenantInfo> >(ServiceLifetime.Scoped));
}
/// <summary>
/// Adds and configures a BasePathStrategy to the application.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.></returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithBasePathStrategy <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder)
where TTenantInfo : class, ITenantInfo, new() => WithBasePathStrategy(builder, configureOptions =>
{
configureOptions.RebaseAspNetCorePathBase = false;
});
/// <summary>
/// Adds and configures a ClaimStrategy with tenantKey "__tenant__" to the application.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithClaimStrategy <TTenantInfo>(this FinbuckleMultiTenantBuilder <TTenantInfo> builder) where TTenantInfo : class, ITenantInfo, new()
{
return(builder.WithStrategy <ClaimStrategy>(ServiceLifetime.Singleton, Constants.TenantToken));
}
/// <summary>
/// Configures authentication options to enable per-tenant behavior.
/// </summary>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithPerTenantAuthentication <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder)
where TTenantInfo : class, ITenantInfo, new()
{
return(WithPerTenantAuthentication(builder, _ => { }));
}
/// <summary>
/// Configures per-tenant authentication behavior.
/// </summary>
/// <param name="config">Authentication options config</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithPerTenantAuthentication <TTenantInfo>(this FinbuckleMultiTenantBuilder <TTenantInfo> builder, Action <MultiTenantAuthenticationOptions> config)
where TTenantInfo : class, ITenantInfo, new()
{
builder.WithPerTenantAuthenticationCore(config);
builder.WithPerTenantAuthenticationConventions();
builder.WithRemoteAuthenticationCallbackStrategy();
return(builder);
}
/// <summary>
/// Adds and configures a RouteStrategy with a route parameter Constants.TenantToken to the application.
/// </summary>
/// <param name="configRoutes">Delegate to configure the routes.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithRouteStrategy <TTenantInfo>(this FinbuckleMultiTenantBuilder <TTenantInfo> builder,
Action <IRouteBuilder> configRoutes)
where TTenantInfo : class, ITenantInfo, new()
=> builder.WithRouteStrategy(Constants.TenantToken, configRoutes);
/// <summary>
/// Adds and configures a RouteStrategy with a route parameter "\_\_tenant\_\_" to the application.
/// </summary>
/// <param name="configRoutes">Delegate to configure the routes.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder WithRouteStrategy(this FinbuckleMultiTenantBuilder builder,
Action <IRouteBuilder> configRoutes)
=> builder.WithRouteStrategy("__tenant__", configRoutes);
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithPerTenantAuthenticationConventions <TTenantInfo>(
this FinbuckleMultiTenantBuilder <TTenantInfo> builder,
Action <MultiTenantAuthenticationOptions>?config = null)
where TTenantInfo : class, ITenantInfo, new()
{
// Set events to set and validate tenant for each cookie based authentication principal.
builder.Services.ConfigureAll <CookieAuthenticationOptions>(options =>
{
// Validate that claimed tenant matches current tenant.
var origOnValidatePrincipal = options.Events.OnValidatePrincipal;
options.Events.OnValidatePrincipal = async context =>
{
// Skip if bypass set (e.g. ClaimsStrategy in effect)
if (context.HttpContext.Items.Keys.Contains(
$"{Constants.TenantToken}__bypass_validate_principal__"))
{
return;
}
var currentTenant = context.HttpContext.GetMultiTenantContext <TTenantInfo>()?.TenantInfo
?.Identifier;
string?authTenant = null;
if (context.Properties.Items.ContainsKey(Constants.TenantToken))
{
authTenant = context.Properties.Items[Constants.TenantToken];
}
else
{
var loggerFactory = context.HttpContext.RequestServices.GetService <ILoggerFactory>();
loggerFactory?.CreateLogger <FinbuckleMultiTenantBuilder <TTenantInfo> >()
.LogWarning("No tenant found in authentication properties.");
}
// Does the current tenant match the auth property tenant?
if (!string.Equals(currentTenant, authTenant, StringComparison.OrdinalIgnoreCase))
{
context.RejectPrincipal();
}
await origOnValidatePrincipal(context);
};
});
// Set per-tenant cookie options by convention.
builder.WithPerTenantOptions <CookieAuthenticationOptions>((options, tc) =>
{
var d = (dynamic)tc;
try
{
options.LoginPath = ((string)d.CookieLoginPath).Replace(Constants.TenantToken, tc.Identifier);
}
catch
{
}
try
{
options.LogoutPath = ((string)d.CookieLogoutPath).Replace(Constants.TenantToken, tc.Identifier);
}
catch
{
}
try
{
options.AccessDeniedPath =
((string)d.CookieAccessDeniedPath).Replace(Constants.TenantToken, tc.Identifier);
}
catch
{
}
});
// Set per-tenant OpenIdConnect options by convention.
builder.WithPerTenantOptions <OpenIdConnectOptions>((options, tc) =>
{
var d = (dynamic)tc;
try
{
options.Authority =
((string)d.OpenIdConnectAuthority).Replace(Constants.TenantToken, tc.Identifier);
}
catch
{
}
try
{
options.ClientId = ((string)d.OpenIdConnectClientId).Replace(Constants.TenantToken, tc.Identifier);
}
catch
{
}
try
{
options.ClientSecret =
((string)d.OpenIdConnectClientSecret).Replace(Constants.TenantToken, tc.Identifier);
}
catch
{
}
});
var challengeSchemeProp = typeof(TTenantInfo).GetProperty("ChallengeScheme");
if (challengeSchemeProp != null && challengeSchemeProp.PropertyType == typeof(string))
{
builder.WithPerTenantOptions <AuthenticationOptions>((options, tc)
=> options.DefaultChallengeScheme =
(string?)challengeSchemeProp.GetValue(tc) ?? options.DefaultChallengeScheme);
}
return(builder);
}
/// <summary>
/// Adds and configures a HostStrategy to the application.
/// </summary>
/// <param name="template">The template for determining the tenant identifier in the host.</param>
/// <returns>The same MultiTenantBuilder passed into the method.</returns>
public static FinbuckleMultiTenantBuilder <TTenantInfo> WithHostStrategy <TTenantInfo>(this FinbuckleMultiTenantBuilder <TTenantInfo> builder, string template)
where TTenantInfo : class, ITenantInfo, new()
{
if (string.IsNullOrWhiteSpace(template))
{
throw new ArgumentException("Invalid value for \"template\"", nameof(template));
}
return(builder.WithStrategy <HostStrategy>(ServiceLifetime.Singleton, new object[] { template }));
}