Microservice Startup Template: Microservices

There are four microservices are included in the microservice startup template;

• IdentityService is located under services/identity folder. This service is an infrastructural microservice and hosts Identity and IdentityServer related functionality and data store.
• AdministrationService is located under services/administration folder. This service is an infrastructural microservice and hosts administrative functionality such as permission-management, setting-management, language-management, audit-logging and such.
• SaasService is located under services/saas folder. This service is an infrastructural microservice and hosts multi-tenancy related functionality and data store.
• ProductService is located under services/product folder. This is a sample microservice to examine and take as a reference for your services.

The infrastructural microservices typically use the pre-built modules.

The microservices are highlighted in the overall solution diagram below:

All microservices;

• Have their own solutions (.sln files) including test projects under their respected folders.

• Depend on SharedHostingMicroservicesModule which contains configuration helpers for JwtBearer authorization, Swagger and DbMigrations,
• Contains configurations for AuthServer, Redis, RabbitMQ, ElasticSearch in appsettings.json file,
• Are capable of on-the-fly database migration; have DbMigrations folder that contains MigrationChecker and MigrationEventHandler. This allows microservices migrate and seed their databases using distributed event bus as an alternative usage to shared DbMigrator,
• Use Sql Server, containing .EntityFrameworkCore layer. This layer contains related database contexts, database context factories and migrations along with related module db configurations

If you want to switch your database provider to MongoDb instead of EntityFrameworkCore for any of the microservice, you need to create .MongoDb project instead of .EntityFrameworkCore. Afterwards, add related modules MongoDb packages dependencies along with similar configurations made in EntityFrameworkCore layer like db context replacement and such. For more, check MongoDB integration.

IdentityService

IdentityService is an infrastructural microservice that provides modular solution by combining the Identity and Identity-Server modules. All the related layers references respected layers of these modules.

Identity-Server Authorization

IdentityService is defined as api resource and api scope with the name IdentityService in IdentityServerDataSeeder.

private async Task CreateApiResourcesAsync()
{
    ...

    await CreateApiResourceAsync("IdentityService", commonApiUserClaims);
    await CreateApiResourceAsync("AdministrationService", commonApiUserClaims);
    await CreateApiResourceAsync("SaasService", commonApiUserClaims);
    await CreateApiResourceAsync("ProductService", commonApiUserClaims);
}

private async Task CreateApiScopesAsync()
{
    await CreateApiScopeAsync("IdentityService");
    await CreateApiScopeAsync("AdministrationService");
    await CreateApiScopeAsync("SaasService");
    await CreateApiScopeAsync("ProductService");
}

See IdentityService Data Seeding for seeding options.

In order make make authorized requests to IdentityService by applications/microservices, IdentityService scope must have been granted for that client.

Web application (Mvc/Angular/Blazor) clients are allowed to request IdentityService scope when created:

private async Task CreateClientsAsync()
{
    ...        
    scopes: commonScopes.Union(new[]
    {
        "AuthServer",
        "IdentityService",
        "AdministrationService",
        "SaasService",
        "ProductService"
    }),
    ...
}

Web Gateway Swagger and Internal Gateway Swagger clients are allowed to request IdentityService scope when created:

private async Task CreateSwaggerClientsAsync()
{
    await CreateSwaggerClientAsync("WebGateway", new []{"AuthServer","IdentityService","AdministrationService","SaasService","ProductService"});
    await CreateSwaggerClientAsync("PublicWebGateway", new []{"ProductService"});
	...
}

AdministrationService client is allowed to request IdentityService scope when created:

private async Task CreateClientsAsync()
{
    ...
    //Administration Service Client
    await CreateClientAsync(
        name: "MyProjectName_AdministrationService",
        scopes: commonScopes.Union(new[]
        {
            "IdentityService"
        }),
        grantTypes: new[] {"client_credentials"},
        secret: "1q2w3e*".Sha256(),
        permissions: new[] {IdentityPermissions.Users.Default}
    );
}

Database Configuration

IdentityServiceDbContext implements

• IIdentityDbContext
• IIdentityServerDbContext

in order to use these module db contexts as combined single db context. However DI container must also dynamically inject IdentityServiceDbContext whenever IIdentityDbContext or IIdentityServerDbContext is requested. The configuration under ConfigureServices provides the runtime database replacement:

context.Services.AddAbpDbContext<IdentityServiceDbContext>(options =>
{
    options.ReplaceDbContext<IIdentityDbContext>();
    options.ReplaceDbContext<IIdentityServerDbContext>();
    ...
});

There is also a SQL configuration for changing the migration table name to separate each service migration history table:

Configure<AbpDbContextOptions>(options =>
{
    options.Configure<IdentityServiceDbContext>(c =>
    {
        c.UseSqlServer(b =>
        {
            b.MigrationsHistoryTable("__IdentityService_Migrations");
        });
    });
});

AdministrationService

AdministrationService is an infrastructural microservice that hosts Permission Management Module, Feature Management Module, Setting Management Module, Audit Logging, Language Management Module, Text Template Management Module, Lepton Theme Module and functioning as combination of these modules. All the related layers references respected layers of these modules.

Identity-Server Authorization

As default; Web application (Mvc/Angular/Blazor), Public Web application, Web Gateway Swagger and Internal Gateway Swagger clients are granted to make requests to AdministrationService scope. The definition of this api resource and scope is done in IdentityServerDataSeeder.

AdministrationService has synched interservice-communication with IdentityService and should be able to make synched http requests to IdentityService order to function properly. This is done by adding this service as a client using client_credentials grant type with name MyProjectName_AdministrationService requesting IdentityService with IdentityPermissions.Users.Default permission. This is used for administration service requesting the user list in administration pages.

//Administration Service Client
await CreateClientAsync(
    name: "MyProjectName_AdministrationService",
    scopes: commonScopes.Union(new[]
    {
        "IdentityService"
    }),
    grantTypes: new[] {"client_credentials"},
    secret: "1q2w3e*".Sha256(),
    permissions: new[] {IdentityPermissions.Users.Default}
);

To make the client_credential requests, IdentityModel configuration is done under IdentityClients section of appsettings along with RemoteServices configuration which points to AbpIdentity to locate IdentityService endpoint. This is done by using [Static C# Client Proxies](https://github.com/abpframework/abp/blob/dev/docs/en/Blog-Posts/2021-11-18 v5_0_Preview/POST.md#static-generated-client-proxies-for-c-and-javascript).

If you need to make requests from AdministrationService to other microservices, you need to add their scope to client creation with required permission as in IdentityService user list request.

Database Configuration

AdministrationServiceDbContext implements

• IPermissionManagementDbContext
• ISettingManagementDbContext
• IFeatureManagementDbContext
• IAuditLoggingDbContext
• ILanguageManagementDbContext
• ITextTemplateManagementDbContext
• IBlobStoringDbContext

in order to use these module db contexts as combined single db context. DI container dynamically injects AdministrationServiceDbContext whenever one of the used modules dbcontext is requested. The configuration under ConfigureServices provides the runtime database replacement

context.Services.AddAbpDbContext<AdministrationServiceDbContext>(options =>
{
    options.ReplaceDbContext<IPermissionManagementDbContext>();
    options.ReplaceDbContext<ISettingManagementDbContext>();
    options.ReplaceDbContext<IFeatureManagementDbContext>();
    options.ReplaceDbContext<IAuditLoggingDbContext>();
    options.ReplaceDbContext<ILanguageManagementDbContext>();
    options.ReplaceDbContext<ITextTemplateManagementDbContext>();
    options.ReplaceDbContext<IBlobStoringDbContext>();
    ...
});

There is also a SQL configuration for changing the migration table name to separate each service migration history table

Configure<AbpDbContextOptions>(options =>
{
    options.Configure<AdministrationServiceDbContext>(c =>
    {
        c.UseSqlServer(b =>
        {
            b.MigrationsHistoryTable("__AdministrationService_Migrations");
        });
    });
});

SaasService

SaasService is an infrastructural microservice that for multi-tenancy functionality and data store.

Identity-Server Authorization

In order make make authorized requests to SaasService by applications/microservices, SaasService scope must have been granted for that client.

As default; Web applications (Mvc/Angular/Blazor), Web Gateway Swagger and Internal Gateway Swagger clients are granted to make requests to SaasService scope. The definition of this api resource and scope is done in IdentityServerDataSeeder.

Database Configuration

SaasServiceDbContext implements

• ISaasDbContext

in order to use this module db context. DI container dynamically injects SaasServiceDbContext whenever the Saas module db context is requested. The configuration under ConfigureServices provides the runtime database replacement

context.Services.AddAbpDbContext<SaasServiceDbContext>(options =>
{
    options.ReplaceDbContext<ISaasDbContext>();
    ...
});

There is also a SQL configuration for changing the migration table name to separate each service migration history table

Configure<AbpDbContextOptions>(options =>
{
    options.Configure<SaasServiceDbContext>(c =>
    {
        c.UseSqlServer(b =>
        {
            b.MigrationsHistoryTable("__SaasService_Migrations");
        });
    });
});

ProductService

ProductService is a sample microservice for examination, created with using Module Development Best Practices & Conventions. Since Microservice template solution is created with modularity in mind, it is pretty straight forward to integrate modules as microservices into the solution.

ProductService solution structure contains .Web layer as library instead of traditional running project which provides modular UI development. When you develop the UI of your application inside the module, it will be rendered in your host application.

Identity-Server Authorization

As default, Web applications (Mvc/Angular/Blazor), Public Web application and all the Gateway Swagger clients are granted to make requests to ProductService scope. The definition of this api resource and scope is done in IdentityServerDataSeeder.

Database Configuration

ProductService.EntityFrameworkCore project contains ProductServiceDbContext, ProductServiceDbContextFactory, EfCoreEntityExtensionsMapping, Migrations, EfCore configuration and ProductRepository implementation. ProductServiceDbContext implements

• IProductServiceDbContext

which contains ProductService specific DbSets. Moreover, there is no need for runtime db context replacement hence there is no configuration related with it.

There is a SQL configuration for changing the migration table name to separate each service migration history table

Configure<AbpDbContextOptions>(options =>
{
    options.Configure<ProductServiceDbContext>(c =>
    {
        c.UseSqlServer(b =>
        {
            b.MigrationsHistoryTable("__ProductService_Migrations");
        });
    });
});

Next

• Microservice Startup Template: Gateways