C4 services model

scope project Dockingjudge:
    "Simple on-premise programming contests management system"




scope context Dockingjudge


system PCMS:
    Programming Contest Management System
    links:
        <-> Monitoring System


system Monitoring System


actor Participant:
    Contest participant
    links:
        --> PCMS over Web UI:
            Reads statements and submits solutions


actor Administrator:
    PCMS Admin
    links:
        --> PCMS over Web UI:
            Creates and manages contests
        --> Monitoring System over Web UI:
            Checks logs and metrics




scope containers Dockingjudge


service Web UI:
    system = PCMS
    tech = React, MUIv1, Nginx
    links:
        <-- Participant
        <-- Administrator
        --> Account Service over HTTP REST API
        --> Contest Service over HTTP REST API
        --> Solution Service over HTTP REST API
        --> Solution Storage over HTTP


service Account Service:
    Manages accounts and performs auth, register, login
    system = PCMS
    tech = DRF
    links:
        --> Account DB


service Account DB [database]:
    Stores account info
    system = PCMS
    tech = Postgres



service Contest Service:
    CRUD for contests and tasks
    system = PCMS
    tech = DRF
    links:
        --> Account Service over HTTP REST API:
            Auth & get user info
        --> Contest DB


service Contest DB [database]:
    Stores contest and task info
    system = PCMS
    tech = Postgres



service Solution Service:
    CRUD for solutions, check quiz solutions, queue code solutions
    system = PCMS
    tech = Python, Litestar, Faststream
    links:
        --> Account Service over HTTP REST API:
            Auth & get user info
        --> Contest Service over HTTP REST API:
            Get contest & task info
        --> Solution DB
        --> Solution Storage
        <-> MQ:
            Queue code solutions and get judge verdicts


service Solution DB [database]:
    Stores solutions
    system = PCMS
    tech = Postgres


service Solution Storage [database]:
    S3 object storage for code solutions
    system = PCMS
    tech = Minio


service MQ:
    "Message queue."
    "Used for asynchronous communication between solution service"
    "and judge services. Also an event queue for object deletion"
    "events for synchronising cascade deletion."
    system = PCMS
    tech = RabbitMQ


service Judge Service:
    Performs routing of solution check requests
    system = PCMS
    tech = Python, Faststream
    links:
        <-> MQ:
            Get queued solutions and queue verdicts
        --> Judgelet over HTTP REST API


service Judgelet [scalable]:
    Performs code solution checks
    system = PCMS
    tech = Python, FastAPI


service Promtail:
    "Logs collector from docker."
    system = Monitoring System
    links:
        --> Loki
        --> PCMS


service Loki:
    "Logs manager. Receives log pushes."
    system = Monitoring System


service cAdvisor:
    "Metrics collector for docker system."
    system = Monitoring System
    links:
        --> PCMS


service Node Exporter:
    "Metrics collector of host."
    system = Monitoring System


service Prometheus:
    "Metrics collector. Attached to all services"
    system = Monitoring System
    links:
        --> cAdvisor
        --> PCMS
        --> Node Exporter


service Grafana:
    Web metrics UI
    system = Monitoring System
    links:
        --> Loki
        --> Prometheus



scope deployment Dockingjudge


deployment VPS Deployment:
    Docker compose:
        deploy Web UI = Docker container
        deploy Account Service = Docker container
        deploy Contest Service = Docker container
        deploy Solution Service = Docker container
        deploy Account DB = Docker container
        deploy Contest DB = Docker container
        deploy Solution DB = Docker container
        deploy Solution Storage = Docker container
        deploy MQ = Docker container
        deploy Judge Service = Docker container
        deploy Judgelet = "Docker container (Scalable)"

        deploy Loki = Docker container
        deploy Grafana = Docker container
        deploy Promtail = Docker container
        deploy Node Exporter = Docker container
        deploy cAdvisor = Docker container
        deploy Prometheus = Docker container