Configuring MongoDB for SCIM Server Persistence

Instead of relying on traditional relational databases, MongoDB offers a document-oriented approach that can simplify schema management and enhance performance in distributed systems. The SCIM server can be configured to connect seamlessly with MongoDB by installing the corresponding NuGet package and updating your application’s startup configuration. With a few lines of code, you can connect to MongoDB, set up your collections, and adjust transaction settings as needed.

To integrate MongoDB with your SCIM server, begin by installing the NuGet package SimpleIdServer.Scim.Persistence.MongoDB. This package provides all the necessary functionality to handle the persistence of SCIM data using MongoDB as the storage engine.

cmd.exe

dotnet add package SimpleIdServer.Scim.Persistence.MongoDB

Next, update your Program.cs file to leverage the MongoDB storage by calling the UseMongodbStorage method. The configuration process involves specifying key parameters such as the connection string, database name, and various collection names.

The following code snippet demonstrates a sample configuration in your Program.cs file:

Program.cs

const string connectionstring = "";
builder.Services.AddScim()
    .UseMongodbStorage(d =>
    {
        d.ConnectionString = connectionstring;
        d.Database = "scim";
        d.CollectionMappings = "mappings";
        d.CollectionRepresentations = "representations";
        d.CollectionSchemas = "schemas";
        d.SupportTransaction = false;
    });
var app = builder.Build();
app.UseScim();
app.Run();

Several properties can be customized during the configuration process. Understanding these properties is crucial for tailoring your SCIM server to meet your organizational needs:

Property	Description
ConnectionString	This is the connection URI used to establish a connection to your MongoDB instance. An example value is mongodb://localhost:27017.
Database	The name of the database where your SCIM data will be stored.
CollectionRepresentations	Specifies the collection used to store core representations such as users, groups, or other entities.
CollectionRepresentationAttributes	Defines the collection for storing specific attributes of the representations—for instance, user first names or other properties.
CollectionSchemas	Indicates the collection where schemas are kept. Schemas define the structure and validation rules for the stored data.
CollectionRealms	Used for storing realms if your SCIM server segregates data based on different domains or contexts.
SupportTransaction	Boolean flag indicating if your MongoDB deployment supports transactions. When set to true, the application can take advantage of atomic operations, which are essential in environments requiring strong consistency.

For more detailed reference, you can check out the example project available on GitHub: SimpleIdServer Sample.

Creating MongoDB Collections

Once your SCIM server is configured and ready to use MongoDB, you can create the necessary collections by calling the EnsureMongoStoreDataMigrated function in your Program.cs file.

Program.cs

var app = builder.Build();
app.Services.EnsureMongoStoreDataMigrated(new List<SCIMSchema>(), new List<SCIMAttributeMapping>(), new List<Realm>());;

This function takes three input parameters:

1. List of SCIM Schemas : You can use the SCIMSchemaExtractor class to extract a SCIM schema from a JSON file. For example:

var userSchema = SimpleIdServer.Scim.SCIMSchemaExtractor.Extract(Path.Combine(basePath, "UserSchema.json"), SCIMResourceTypes.User, true);

2. List of attribute mappings : These mappings define parent-child relationships between different representation types. For instance, between a Group and a User.

The following code snippet defines the relationship from a Group to a User. The members property of a group contains a list of users:

new SCIMAttributeMapping
{
    Id = Guid.NewGuid().ToString(),
    SourceAttributeId = groupSchema.Attributes.First(a => a.Name == "members").Id,
    SourceResourceType = StandardSchemas.GroupSchema.ResourceType,
    SourceAttributeSelector = "members",
    TargetResourceType = StandardSchemas.UserSchema.ResourceType,
    TargetAttributeId = userSchema.Attributes.First(a => a.Name == "groups").Id,
    Mode = Mode.PROPAGATE_INHERITANCE
}

The next snippet defines the reverse relationship, from a User to a Group. The groups property of a user contains a list of groups:

new SCIMAttributeMapping
{
    Id = Guid.NewGuid().ToString(),
    SourceAttributeId = userSchema.Attributes.First(a => a.Name == "groups").Id,
    SourceResourceType = StandardSchemas.UserSchema.ResourceType,
    SourceAttributeSelector = "groups",
    TargetResourceType = StandardSchemas.GroupSchema.ResourceType,
    TargetAttributeId = groupSchema.Attributes.First(a => a.Name == "members").Id
}

3. List of realms : The third parameter specifies the list of realms to initialize. For more details, refer to the dedicated chapter on realms.