```mermaid
sequenceDiagram
    participant User
    participant REANA
    participant GitLab
    participant CERN SSO
    User->>REANA: login
    REANA-->>User: redirect to cern
    User->>CERN SSO: cern login
    CERN SSO-->>REANA: cern authentication
    User->>REANA: gitlab authorization
    REANA-->>User: redirect to gitlab
    User->>GitLab: gitlab authorization
    GitLab-->>REANA: authorization
    REANA->>GitLab: request user projects
    GitLab-->>REANA: send user projects
    REANA->>User: display projects
    User-->>REANA: select project
    REANA->>GitLab: setup webhook
    User->>GitLab: project commit
    GitLab-->>REANA: trigger workflow execution
    REANA->>GitLab: update commit status
    GitLab-->>User: send commit status notification
    User->>REANA: request logs
    REANA-->>User: display logs
```