Architecture

microCMDB.CLI is a single-process console application. This page describes how it is put together.

Process flow

Program.Main
  └─ Shell.Prep()           # create the in-memory Db and seed example data
  └─ loop: Shell.CLI()      # read a line, dispatch a command, repeat

• Program.Main (Program.cs) sets the working directory, marks the session as hosted, and runs the shell loop until Program.running becomes false.
• Shell.Prep (Util/Shell.cs) constructs a Db and seeds it.
• Shell.CLI reads a line, splits it into a command and arguments, and dispatches through a switch. On EOF (Ctrl-D / end of piped input) it exits cleanly.

The in-memory database

Db (Db.cs) is not a real database — it is a bag of List<T> collections (one per entity and per mapping type) held in a single static instance:

public static Db? CurrentDbContext { get; set; }

All reads and writes go through Db.CurrentDbContext. The naming mirrors Entity Framework’s DbContext, but there is no persistence: state lives only in memory and is lost on exit unless you export.

Self-registering entities

Entities do not need to be added to the database explicitly. Every model’s constructor registers the new instance into the current context. The base Entity constructor assigns a DbTag and adds the instance to Entities; each derived constructor also adds itself to its specific collection:

public ConfigItem() : base()
{
    Db.CurrentDbContext.ConfigItems.Add(this);
}

This keeps seeding and creation terse, but it has consequences worth knowing — see Known Issues (e.g. a live Db.CurrentDbContext must exist before any entity is constructed, and explicit Add calls can double-register).

Layers

Namespace	Responsibility
microCMDB.CLI	Entry point (Program) and the Db context.
microCMDB.CLI.Models	Entity types (ConfigItem, Node, Host, Service, Software, NetworkUser, Publisher, Developer, Manufacturer).
microCMDB.CLI.Models.NavProps	Mapping/join types that express relationships.
microCMDB.CLI.Util	Command handlers and helpers: Shell, Get, Set, New, IO, Help, Table.

Output rendering

Util/Table.cs provides the fixed-width table primitives (PrintLine, PrintRow) used to render entities. Each entity overrides PrintInfo() to lay out its own fields.

Import / export

Util/IO.cs handles CSV export (one file per collection) and import. Each entity implements ExportObject() to produce its CSV row. See the Data Model page for the on-disk format.

Runtime targeting

The CLI targets net6.0 for source compatibility with microCMDB.OS, which is harder to move off .NET 6. Because no .NET 6 runtime is typically installed, the project sets <RollForward>Major</RollForward> so it runs on .NET 8/9 on the host. The Docker image instead uses the .NET 6 base images and runs natively.