54 lines
2.6 KiB
Markdown
54 lines
2.6 KiB
Markdown
# The System Bus: syndicate-server
|
|
|
|
- Source code: [`[syndicate-rs]/syndicate-server/`](https://git.syndicate-lang.org/syndicate-lang/syndicate-rs/src/branch/main/syndicate-server)
|
|
- Packaging: [`[synit]/packaging/packages/syndicate-server/`](https://git.syndicate-lang.org/synit/synit/src/branch/main/packaging/packages/syndicate-server)
|
|
|
|
The `syndicate-server` program has a number of closely-related functions. In many ways, it is a
|
|
reification of the [system layer concept](../glossary.md#system-layer) itself.
|
|
|
|
It provides:
|
|
|
|
1. A **[root system bus](#the-root-system-bus)** service for use by other programs. In this way, it is
|
|
analogous to D-Bus.
|
|
|
|
2. A **[configuration language](./scripting.md)** suitable for programming
|
|
[dataspaces](../glossary.md#dataspace) with simple reactive behaviours.
|
|
|
|
3. A general-purpose **[service dependency tracking facility](./service.md)**.
|
|
|
|
4. A [**gatekeeper** service](./builtin/gatekeeper.md), for exposing
|
|
[capabilities](../glossary.md#capability) to running objects as (potentially long-lived)
|
|
[macaroon](../glossary.md#macaroon)-style "sturdy references", plus TCP/IP- and
|
|
Unix-socket-based **[transports](./builtin/relay-listener.md)** for accessing capabilities
|
|
through the gatekeeper.
|
|
|
|
5. An [`inotify`](https://en.wikipedia.org/wiki/Inotify)-based **[configuration
|
|
tracker](./builtin/config-watcher.md)** which loads and executes configuration files written
|
|
in the scripting language.
|
|
|
|
6. [**Process startup and supervision**](./builtin/daemon.md)
|
|
services for running external programs.
|
|
|
|
The program can also be used as an "inferior" bus. For example, there may be a per-user bus, or
|
|
a per-session bus, or both. Each bus would appropriately scope the lifetime of its supervised
|
|
processes.
|
|
|
|
Finally, it can be used completely standalone, outside a Synit context.
|
|
|
|
## The root system bus
|
|
|
|
The [`synit-pid1`](./index.md#sbinsynit-pid1) program invokes `syndicate-server` like this:
|
|
|
|
/usr/bin/syndicate-server --inferior --config /etc/syndicate/boot
|
|
|
|
The first flag, `--inferior`, tells the server to expect to be able to communicate on its
|
|
stdin/stdout using the [standard wire protocol](../protocol.md). This lets `synit-pid1` join
|
|
the community of actors running within the system dataspace.
|
|
|
|
The second flag, `--config /etc/syndicate/boot`, tells the server to start monitoring the
|
|
directory tree rooted at `/etc/syndicate/boot` for changes. Files whose names end with `.pr`
|
|
within that tree are loaded as configuration script files.
|
|
|
|
Almost all of Synit is a consequence of careful use of the configuration script files in
|
|
`/etc/syndicate`.
|