This product is a Go implementation of the CAPIF Core function, which is based on the 3GPP "29.222 Common API Framework for 3GPP Northbound APIs (CAPIF)" interfaces, see https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=3450.
The nearly complete data model for CAPIF is shown in the diagram below.
The data used within CAPIF Core for registering rApps that provide and consume services is shown in the diagram below.
Some examples of interactions between components using the CAPIF interface are shown in the sequence diagram below.
NOTE! It has not been decided that CAPIF Core will actually handle the Helm chart installation. The prototype includes this as an example of what CAPIF Core could potentially do.
If Helm is used, before publishing a service, the chart belonging to the service must be registered in ChartMuseum. When publishing the service the following information should be provided in the ServiceAPIDescription::description attribute; "namespace", "repoName", "chartName", "releaseName". An example of the information: "Description of rApp helloWorld,namespace,repoName,chartName,releaseName".
The CAPIF APIs are generated from the OpenAPI specifications provided by 3GPP. The generate.sh script downloads the specifications from 3GPP, fixes them and then generates the APIs. It also generates the mocks needed for unit testing. The specifications are downloaded from the following site; https://www.3gpp.org/ftp/Specs/archive/29_series. To see the APIs in swagger format, see the following link; https://github.com/jdegre/5GC_APIs/tree/Rel-16#common-api-framework-capif. NOTE! The documentation in this link is for release 16 of CAPIF, the downloaded specifications are for release 17.
To fix the specifications there are three tools:
commoncollector, collects type definitions from peripheral specifications to keep down the number of dependencies to other specifications. The types to collect are listed in the definitions.txtfile. Some fixes are hard coded.enumfixer, fixes enumeration definitions so they can be properly generated.specificationfixer, fixes flaws in the specifications so they can be properly generated. All fixes are hard coded.When a dependency to a new specification is introduced in any of the CAPIF specifications, see example below, the following steps should be performed:
For the CAPIF specification "TS29222_CAPIF_Discover_Service_API" a new dependency like the following has been introduced.
websockNotifConfig:
$ref: ✅TS29122_CommonData.yaml#/components/schemas/WebsockNotifConfig✅'
definitions.txt file. This step is not needed if the type is already defined in the file.generate.sh script, between the "<replacements_start>" and "<new_replacement>" tags, to see if "TS29122_CommonData" has already been replaced in "TS29222_CAPIF_Discover_Service_API".The security requirements applicable to all CAPIF entities include providing an authorization mechanism for service APIs from third-party API providers and supporting a common security mechanism for all API implementations to ensure confidentiality and integrity protection.
In the current implementation Keycloak is being used as identity and access management (IAM) solution that provides authentication, authorization, and user management for applications and services. Keycloak provides robust authentication mechanisms, including username/password, two-factor authentication, and client certificate authentication that complies with CAPIF security requirements.
A docker-compose file is included to start up keycloak.
To generate mocks manually, run the following command:
go generate ./...
NOTE! The helmmanagement package contains two mocks from the helm.sh/helm/v3 product. If they need to be regenerated, their interfaces must be copied into the helm.go file and a generation annotation added before running the generation script.
To build the application, run the following command:
go build
To run the unit tests for the application, run the following command:
go test ./...
The application can also be built as a Docker image, by using the following command:
docker build . -t capifcore
To run the Core Function from the command line, run the following commands from this folder. For the parameter chartMuseumUrl, if it is not provided CAPIF Core will not do any Helm integration, i.e. try to start any Halm chart when publishing a service.
./capifcore [-port <port (default 8090)>] [-secPort <Secure port (default 4433)>] [-chartMuseumUrl <URL to ChartMuseum>] [-repoName <Helm repo name (default capifcore)>] [-loglevel <log level (default Info)>] [-certPath <Path to certificate>] [-keyPath <Path to private key>]
Use docker compose file to start CAPIF core together with Keycloak:
docker-compose up
NOTE! There is a configuration file in configs/keycloak.yaml with information related to keycloak host, when running locally the host value must be set to localhost (Eg. host: "localhost") and when using docker-compose set value of host to keycloak (Eg. host:"keycloak")
Before using CAPIF API invoker management, an invoker realm must be created in keycloak. Make sure it is created before running CAPIF core. After creating the realm in keycloak, set the name in the keycloak.yaml configuration file.
To run CAPIF Core as a K8s pod together with ChartMuseum, start and stop scripts are provided. The pod configurations are provided in the configs folder. CAPIF Core is then available on port 31570.
A Postman collection has been included in this repo at sme/postman/CAPIF.postman_collection.json.