Container

A Container represents an application or a data store. It is something that needs to be running in order for the overall software system to work.

Note: In C4, “Container” does not mean a Docker container. It means a deployable unit like:

• Server-side web application (e.g., Java Spring, ASP.NET Core)
• Client-side web application (e.g., React, Angular)
• Mobile app
• Database schema
• File system

Syntax

import { * } from 'sruja.ai/stdlib'


ID = container "Label/Name" {
technology "Technology Stack"
tags ["tag1", "tag2"]
// ... contains components
}

Example

import { * } from 'sruja.ai/stdlib'


BankingSystem = system "Internet Banking System" {
WebApp = container "Web Application" {
  technology "Java and Spring MVC"
  tags ["web", "frontend"]
}
}

Scaling Configuration

Containers can define horizontal scaling properties using the scale block:

import { * } from 'sruja.ai/stdlib'


API = container "API Service" {
technology "Go, Gin"
scale {
  min 3
  max 10
  metric "cpu > 80%"
}
}

Scale Block Fields

• min (optional): Minimum number of replicas
• max (optional): Maximum number of replicas
• metric (optional): Scaling metric trigger (e.g., “cpu > 80%”, “memory > 90%”)

This helps document your auto-scaling strategy and can be used by deployment tools.